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Vorshlag 2015 Mustang GT Road Race Build #TRIGGER

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  • #16
    continued from above

    The radiator hoses we make have proven to be reliable over the years. We're just trying to connect the radiator to the engine with hoses that have some flexibility, the right sizes, and never leak. The hoses often need to compensate for size changes between the water pump and the radiator; 1-1/2", 1-5/8" and 1-3/4" are all common sizes.

    We start at the ends, sourcing these from Pegasus, HPS, and others. Parts took weeks to all arrive, test fit (above left), then it was time to connect the ends with aluminum tubing - all while trying to leave as much access room and radiator exhaust airflow room as possible. Sure, we could have modified the radiator and water pump to use -20 AN ends and built AN braided hoses for all of this, but it adds 5x the fab time and cost - plus makes sourcing a replacement water pump at a remote race weekend impossible.

    We tend to make the hose bends and the adaptation between diameters on these silicone hose end sections. We connect the hose ends & bends on this install with straight 1.5" OD aluminum tubing, as shown above. We add these raised beads on the tubing at the ends, to help secure the hoses, using our little bead roller. Sure, you can often hack together some OEM rubber hoses from a car parts store, but these silicone + aluminum assemblies look good, work well, and do not leak - when built correctly.

    These also have just enough flexibility to allow the engine a little movement (from torque). We use these turbo style T-bolt clamps to secure each junction, which have smooth inner clamp surface - unlike worm gear hose clamps. I will talk about the "steam vent" port and plumbing we added in the highest hose (see above right) in a future post.


    The trunk of this car has two GIANT mufflers, a differential cooler, battery, remote surge tank and more. The rear seat is never going back into this car, so we have a giant hole between the trunk and the cabin. So let's make that hole even bigger!

    To make the trunk firewall the rear speaker deck became pointless - it had two massive holes in it, plus lots of little holes and raised bits. Brad and I discussed this in February and he marked the main upper "structural beam" at the upper leading edge. This ties the two shock towers together and we want to keep that structure for now. The perimeter was marked and he used lots of tools to cut out this piece.

    This speaker deck amounted to only 2.5 pounds (above left), but there were some raised sections in the remaining portion (above right) that had to be cut & ground away so a flat sheet could go over this panel with tight gaps. The point here is to seal air, fumes, and potential fuel / fire from reaching the cabin, so tight gaps to the remaining structures the firewall bolts to are key.

    Brad got all of the metal trimmed and flat, taped off the raw ends and primed them - no more rusty metal - then got to work on the two pieces that would be made from aluminum sheet for the firewall.

    Hot bits in the trunk with big openings that need to be sealed off from the cabin, as seen above.

    The main "vertical" matches the back seat angle and mounts to a flat section of vertical structure on both sides of the main opening. This sheet was relatively easy to shear and fit to the car. The upper deck replacement was trickier and Brad made a full sized cardboard template for that.

    There are two other portions that will remain in place on the sides of the back seat opening (see above left). These are riveted in place. The main vertical panel is bolted in place with button head bolts into rivnuts. The upper panel has a bend along the top leading edge and that bolts to the cross structure and overlaps the vertical panel (see above right). There are bolts along the back edge of the upper panel as well. Don't worry, the Lexan rear window will be removed with bolts as well - so if we need to remove this firewall we can, just takes a bit of time.


    Things were really speeding up on the project here - with a bulk of the work in this post done in February '22, when we had a gap in customer work while we waited on a bunch of parts. Instead of making the trunk mounting complicated I decided to go ahead and ask Brad to install the stock trunk release latch and striker. It has never been closed up until now...

    As I mentioned in previous posts before, this is an Anderson Composites carbon trunk, and it is very light - but has all the features and mounting points of the OEM trunk. This allows all of the factory hinges, brackets, and latches to bolt right up. As you can see above it also fits very well - we just bolted it on, and it fit like this.

    Then it was time to really look at the trunk release. There won't be "keys" or remote solenoids on the doors or trunks on this race car, so we kept it simple and used an extra Lifeline remote fire bottle pull handle cable as the trunk release (above right). This would attach to the "emergency release" handle on the latch, mandated to be inside all trunks - in case someone is trapped inside. Brad made a bracket to mount the cable pull to the inner sheet metal behind the passenger door and the handle is reachable from the passenger side window opening.

    Simple, effective, easy to see - and we'll add a proper label to the "pull" and a decal outside that window pointing to "trunk release", too. First time we have closed the trunk on this car, which was a nice thing to check off the ever shrinking To Do List.


    As I have stated before, we're re-using an OEM fuel tank in this build along with a remote surge tank. This mega-stripped salvage car came with nothing back here - no tank, zero fuel system plumbing, nothing. So we had to track down some OEM bits (tank + stock pump / float assembly + in-tank crossover hoses) and then build the rest.

    We got a stock fuel pump and sump assembly from my buddy Paul at Tri State Autoparts, and then got to work modifying that. The stock pump will be used just as a lift pump, which should be more than adequate at pushing fuel from the stock tank to the Radium remote surge tank.

    Paul left us the stock "pig tail" so we can wire up the stock pump easily. We've drilled into the top of this plastic housing for the "overflow" return from the surge tank at the top. Then the quick connect for the stock feed line from the stock pump has an adapter to a -8 AN end, as shown above right. That's how we get fuel out of the stock pump and excess goes back in.

    The feed and "overflow" lines are both -8 AN braided Fragola hoses, which Doug built and attached to this side. These feed up through the back seat and unto the trunk. The top of this side of the fuel tank will get another cover to act as a "firewall" to the cabin - I'll show that next time.

    The stock filler neck nipple (not shown) connects to the filler neck hose, which is the only stock plumbing hose left on the fuel system. Above left is the big 5/8" quick connect for the "vent" on the stock tank. This allows air to escape when the tank is being filled as well as to allow air back in when the fuel level goes down. We found this AN adapter from Motion Raceworks and it connects to a big -10 AN hose that goes to the vent stack, shown below.

    Next up comes the fuel tank vent system, and all this was done so we can do away with the factory charcoal filter (which is long gone). We are trying to vent the tank for filling and use, as well as make a "rollover valve". We started with a valve cover breather with a 5/8" opening, then a 5/8" barbed fitting to -10 AN, and finally this Vibrant -10 AN/ORB one-way check valve. The check valve was opened up and the spring modified to have a lower spring pressure. This way if the car ever rolls over on its lid, it acts as the rollover valve. It still should have enough spring pressure to keep the fuel separated from atmosphere as a check valve. If there are excess fuel fumes in use we will address this then, but with the sealed trunk firewall, it may be a non-issue.

    Doug made a bracket to hold for the lower check valve portion, then machined that fitting to work like a bulkhead fitting at the bracket. The check valve is mounted at the trunk floor level (as shown below), then a ~18" long hose goes up to another bracket at the top of the trunk, which mounts the breather. This is mounted higher than the external fuel filler neck on the fender, to keep fuel from ever coming up and out this vent.

    Next up was the Radium Remote Surge Tank, which we spec'd out with two Walbro 450 LPH pumps. This is tad overkill for the Phase 1 engine, but the single pump setup was a bit short. This has room for up to 3 pumps, and we will add a third when we go to Phase 2. We ordered this one "bare" so we needed to add the pumps, fuel hose, and wiring.

    These setups are modular and easy to work with. We ordered it made for the Walbro 450s and Doug made quick work of the assembly. The included screen at the bottom is made to hold these Walbros and he used submersible hose for the connections at the top. The included wiring was connected to the machined Radium top plate, which has wiring bulkhead connectors for all 3 pumps (6 posts) and another spot for a fuel level sensor.

    We added this optional fuel level float sensor, which basically tells you that the surge tank is NOT full - which is usually a "OMFG GET TO THE PITS NOW" warning. We'll mount a big LED in the center stack to warn the driver when this ever happens.

    The Radium sensor has the two pink wires that come out of the hole, which is sealed by the float assembly from the underside. As you can see the float only moves about 1/2" and it is near the top of the surge tank, letting you know you have drained the main fuel tank and are on the emergency reserve that is within the surge tank only.

    With the pumps and sensor installed and wired inside the Radium surge tank it was re-mounted in the trunk and the fuel lines plumed to and from that to the main tank. Two of these line run under the back seat floor and into the trunk, as shown in the two pictures above. The other two lines go to the rear bulkhead under the car for the main -10 / -8 lines to and from the engine bay. Fuel system plumbing is now complete - wiring and relays will happen in the next installment.


    I have a lot of experience with car batteries, which can be made very light - but it always comes at a cost. After 3 decades of this stuff I have settled on larger batteries of AGM / gel cell types. Of the Optima series I like their 75/25 group options, and on a race car we use the heavier Yellow Tops (thicker plates/can be discharged to zero) vs the lighter Red Tops (thinner plates/higher CCA).

    Nobody makes a good battery mount for these, but we do - shown below. Our mount is a steel lower tray we CNC cut and bend, then an aluminum upper. We've used these in numerous race car builds. First step is to find a good place to mount it.

    I looked all over the LS550 for a spot and had my eye on this this lateral cross beam in the forward section of the trunk floor. There was a thick layer of sound deadening material here but otherwise it was flat, so I asked Doug to use a heat gun and scrape that area clean.

    The bottom of our battery tray has 6 holes pre-cut for hold-down bolts, which can sit above the top of the tray and fit inside the voids on the bottom of these spiral wound Optima designs (see above left). I asked Doug to add 4 more tabs for even more bolt holes - because the section where we can bolt down the steel tray is "blind". This area is a thick hollow section and we would need to add Rivnuts here to mount the battery.

    Yes I know this is less than ideal, but it was the "least bad" spot to put the battery for easy access, weight bias, and where much of the rear wiring would be anyway. These are LARGE for rivnuts, they were installed with a pneumatic gun, and there are eight of them. This battery is not coming loose in any crash, and we have a bomb-proof rear bulkhead right in front of it. I have zero worries here. I will show the battery wiring in the next forum update.


    Some of you saw in my last post where I talked about buying this narrow body 2006 C6 we bought last year. We bought this to hold me and my wife over until this LS550 and her LS 86 are both on track, to keep our track skills fresh and to not wither away behind a keyboard for the ~3 years it took us to get this LS550 almost ready. Some wondered if this C6 would be a distraction or replacement that kept us from working on our two race cars.

    We had upgraded to these cheap flow formed 19x10" wheels (2 sets) and 275/35R19 Hankook RS-4s - which I bought for long term testing consistency, but as an "endurance" 200TW tire is gives up some speed. We chased a particularly nasty ABS issue on this car for a long time, but eventually just punted and swapped in BMW Mk60 ABS and that solved that. This ABS fix & 275mm tire upgrade helped this stock LS2 powered (360 whp) car go from 1:30.0 to 1:26.2 lap times at MSR on the 1.7. Then this 3100 pound C6 got MCS RR2s coilovers and it dropped nearly 4 more seconds into the 1:22 range on these same tires just a week ago.

    Honestly, this big lap time drop on the C6 motivated me to get our LS550 finished - because this C6 is roughly the final weight we will be at in this S550 (see recent weight check, above left), but we should start phase 1 at nearly +180 whp and be on better 305mm RE-71Rs (I have a fresh set to test with) and then the 315mm Hoosiers.


    I think this is a good place to stop, before this post gets too long. This round of updates caught us up with work done into March 2022, which is close to when I'm writing this. We have some more work completed during the period while I was writing this - the heater core is mounted, the coolant reservoir as well, and the Peterson vented oil catch can. Some small plumbing to wrap up on this round, too.

    The carbon doors are already being fitted to be installed soon, to keep the total weight down for Phase 1. Just some final wiring to knock out, digital dash, and tuning. Then we'll be on track "sooner rather than later".

    Thanks for reading!
    Terry Fair -
    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


    • #17
      Project Update for September 20th, 2022: The last update here was April '22 and I'm updating it again in September - only a five month gap - so we're getting caught up on many build threads. I used one of the boring "sea days" on board a cruise (Sept 17th) to write much of this update, and my internet connection was crap, but its better than staring at the ocean for 8 straight hours.

      We haven't really attacked the LS550 build as much as I wold have hoped, but between customer builds we are getting more and more done - and all four remaining customer builds are wrapping up and leaving quickly! That means we will be able to pour more man hours into this car and get it fired up VERY soon. We're are down to wiring then First Fire followed by alignment and dyno tune.

      The shop is still full of cars, and my former red 2018 GT even arrived for a T56 Magnum XL swap (among other work) earlier in 2022, and you can see that + our black LS550 + our narrow body C6 in the image above.

      Looking back over the last 5 months now, we actually did knock out a decent chunk of work, with Brad and Doug tag teaming the punch list on this Mustang. And I'm not helping things, as I keep adding more features and details along the way (just like our customers do!) - but this car is going to be our main "shop race car" for a few years, so it has to perform well AND look good.

      In this installment we cover the last steps of the cooling system, the oil vent catch can plumbing, the Lexan back window install, carbon doors and even the new paint applied to the front fenders and nose - so now the car is all black or raw carbon! We also cover the steering wheel quick disconnect with a horn, digital dash mock-ups, shifter modifications, and a detailed guide to installing a fire suppression system. Its a big 3-part installment so get to a real computer (ie: a larger monitor - every image is linked to a higher rez version!), grab a snack and/or drink, and lets get caught up on this build!


      We covered the radiator mounts and main radiator hoses last time, but in this round we will show the last bits of the cooling system being installed - namely, the heater core, defroster plenum, coolant reservoir, then heater and steam vent hoses .


      We race 12 months out of 12 here in Texas, and our winters can and do get below freezing. I have been to a number of January events where there was frost or fog on the windshield so we always like to add a defroster to all of our race cars. Having a working heater will also help in Optima events - which this car will do.

      The first step to getting the heater core mounted was removing the dash, which needs the doors off to access the mounting bolts - shown above left. And this step led to the carbon doors going on, shown below!

      The dash in this 2015 GT was only loosely installed, as it was a parts car quickly thrown together from leftovers before I bought it. Brad worked on fitting the dash better for the reinstall by adjusting these screw-in width adjusters, so it won't be flopping around. With the 22.5 pound OEM "HVAC" box out of the way, the new 7.4 pound motorsports heater core looks tiny sitting on the trans tunnel.

      We have used this 7.4 pound heater core from Summit Racing on many race cars for the past decade. It has a heater core inside, two outlets which fit up to 3" hoses, and a variable speed fan on the back side. All self contained and easy to mount - but we never use the included "universal" mounting brackets.

      Doug made up a simple aluminum sheet metal bracket which bolts to the tunnel (into rivnuts), placing the core far enough behind the dash's center stack portion, but still with enough room to access the heater hose nipples. I am a fanatic about firewall integrity and insist on bulkhead connectors for all plumbing and virtually all wiring pass-thrus for any firewall.

      The heater hoses going to and from the heater core here were another place for these stainless bulkheads. These have nipples made for simple hose clamps and hoses, which are fine for low pressure cooling systems (16 psi) we tend to run. For a higher pressure fluid system we would be using AN fittings. The placement for these two were planned out along with the reservoir mounting spot and several other items in that area. I will show the final plumbing in the heater hose section below.


      In this step I will show how we will turn our heater box into a defroster - without trying to hobble together something with the OEM defrost plenum, which would be pretty ugly. I had found a potential "plenum" on Amazon, which you will see below.

      First up was measuring the defroster inlet on the factory dash, shown above. Then Doug made a block off plate for part of that, which will make sense in a later step. This is made from aluminum sheet stock and bolts to the underside of the plastic dash.

      Above you can see the "plenum" that i found online - its a shop vac attachment that was $12. Much cheaper than making a complicated aluminum structure. This bolts to the opening that we left from the block off plate above and has a 3" OD hose inlet that will attach to one of the two 3" outlets from the heater core. Above right you can see the silicone heater hoses that go from the core to the bulkheads at the firewall.

      The dash went back in and I missed the connection of the hoses to the defroster plenum and eyeball vent, but they are there. The second outlet from the heater box feeds a single heater vent - one of the three "eyeball" vents in the center of the dash. I can open that vent up if I need to warm my hands in grid, but mostly it will remain closed. When the heater fan is on that will blow the warm air to the base of the windshield, to keep it from fogging up on cold / wet days. The other 2 round vents on the dash will house some gauges, later on.


      We use a remote coolant reservoir in these LS builds. This allows us to mount the reservoir and radiator cap high in the engine bay, which allows for a better "purge" of air pockets. The larger the tank the more coolant we can have on board also. We tie this into the cooling system in two ways - via the steam vent system as well as through one of the heater hoses. And we try to use an aluminum version whenever possible, as these don't age and crack like the OEM plastic style.

      We have used this big Canton remote reservoir before, as well as the Canton 16 psi cap. We test fit a 1/2" NPT fitting for the bottom bung and it was a bit too shallow so Doug ran a 1/2"-14 NPT tap a little further into that bung to allow the elbow to sit a little deeper.

      The Fragola lower 90 deg elbow went from the threaded 1/2" NPT to a 5/8" diameter hose barb. This is Teed into one of the 5/8" dia heater hoses going to the firewall bulkhead. Above right you can see the steam vent hose which went into the upper 1/8" NPT bung. That ties into our 4 port steam vent system AND the same port at the top of the upper radiator hose.

      The two images above show the routing of the heater hoses from the LS7 water pump to the bulkheads at the firewall as well as the "T" that diverts some of that flow to fill the reservoir (and also to fill the cooling system from above, when the cap is off).

      The upper radiator hose is the highest part of the cooling system and radiator below the reservoir, and we added a small port to that with a nipple that Tees into the 4 port steam vent outlet. This hose then runs from that junction at the radiator hose to the reservoir at the back right corner of the engine bay.

      This should tie the highest part of the cooling system inside the engine (steam vent system) to the highest part of the radiator (the upper radiator hose port) to the highest part of the entire system (the remote reservoir), removing any steam pockets in the system.


      Any car driven on a road course with an internal combustion engine should have an oil/air separator and catch can system. This prevents excessive crank case pressure from spewing oil out of the engine - either into a sealed EGR system or an open vented system, like on this car. I explain the difference between these two types of oil catch can systems in this recent post on our narrow body C6 - and it applies here.

      Since this going to be more "Race car" than "Daily driver", we went with a vented oil catch can from Peterson oil systems. This has an internal filter to catch the liquid oil droplets and keep them from spewing out of the vent at the top of the can (again, see the post on the C6 section showing this). This Peterson can is our "go to" option for race cars that have a wet sump oiling system.

      To feed the crankcase pressure to this air/oil separator we needed to run big vent lines from both valve covers. The cast aluminum, tall, red "CHEVROLET" valve covers both got holes drilled to have 1/2" NPT fittings threaded. the Fragola fittings were then shortened on the bottom side so that they do not come close to the rocker arms - that would be bad!

      That leaves two big -12 AN fittings on the back of both valve covers, which Doug then plumbed to the two inlet ports on the Peterson can with AN12 Fragola hoses.

      This works our for a clean, dual fed, crank case vent system with an oil / air separator inside the can. There is a drain port at the bottom of the can which has a petcock, that Doug then plumbed with a hose down inside the RF fender area. After every track event we can open this petcock and drain the captured oil to keep the can from filling up. Again - every road raced car should have some sort of oil / air separators with a catch can and drain.

      S197 ABS INSTALL

      Wait, what?! We already had an S550 ABS system installed on this car earlier! Alas, since we installed a salvage yard sourced S550 ABS unit, as well as a master cylinder and lines from Ford, we have learned of CAN challenges with S550 ABS swaps. Namely - that is has never been done, and involves a LOT more CAN signals from OEM computers we don't have in this car. That is more work than we are ready to tackle at the moment.

      The S550 ABS unit has been removed, boxed up, and shelved - for now. Instead of tilting that windmill, we instead decided to go with an ABS unit we know well and have successfully swapped into other chassis - the S197 ABS unit from a 2011-14 Mustang GT. These exist in the tens of thousands in salvage yards, after countless Mustangs have unsuccessful avoided ditches, trees, curbs and crowds.

      Now I personally have driven 100s of laps in S197 Mustangs with this late 2011-14 ABS, both on track as well as autocross. And we know that we can make this work without ANY of the stock CAN inputs, if we use the right Ford Racing ABS computer, which we do have on hand for this car. But using a factory manual & wiring diagrams, plus a donor car we have on site (2011 Mustang chassis), we want to test some theories on an S197 ABS swap without using the expensive and rare Ford Racing computer (it is out of production and getting very hard to source!)

      Again, if I thought there was a way to make the S550 ABS unit work with this completely CAN-free car, we would. This will save us months of frustration - and help prove out some alternatives for other chassis we want to ABS swap. We've done a number of Mk60 ABS swaps and one S197 swap, so this is just another option. We reached out to our friend Paul at Tri-State Auto to source a 2011-14 ABS brick + mount + harness connector, and he delivered once again. The image above right shows the S197 ABS next to the S550 - similar in many ways but still very different.

      Now to be on the safe side we went ahead and mounted the S197 ABS unit at the same angle as Ford did (see above left). This will be oriented the same way and tilted at the same 18 deg angle. The S550 ABS unit (above right) sits "straight up", without this tilt. We planned to place the S197 unit in the same basic spot as the S550 unit, but with the 18 deg tilt.

      I labeled the two units with the outputs of both units on the "top, but the input ports are on different planes. Doug then mocked up the S197 ABS brick in the engine bay with the 18 deg tilt, and it looks accessible. Now it was time to make the bracket and then the lines.

      Doug took the S197 ABS brick's mounting bracket (which was bent / damaged) and flattened it out, then made a template of that. This was then modified to fit the S550 chassis. It took two versions to get everything aligned correctly but the CNC plasma table made this go quickly.

      The second version was bent up to fit the ABS brick and the S550 chassis mounting points, then the S197 isolators were added to the big holes cut to accept those. This allows the hydraulic unit to not vibrate as it cycles, which can throw off the actuation. We do this isolation mounting on every ABS swap.

      We received the S197 unit from salvage with the correct hard line fittings (tube nuts) and the harness with a "tail" of wires we can re-use. That proved to be critical, as the S197 and S550 used different end fitting flare angles on the M10 and M12 ends. Why? Nobody knows! You can see our S197 adapter bracket bolted into the S550, above right.

      Doug caught this tube nut fitting difference - it was all lining up perfectly, but now we had to cut each hard line in the car, swap in the S197 tube nut, then re-flare each end. A bit cumbersome with the hard lines still in the car, but Doug used this pneumatic flaring tool to get them all swapped.

      continued below
      Last edited by Fair!; 09-20-2022, 01:56 PM.
      Terry Fair -
      2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
      EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


      • #18
        continued from above

        Even the two "flex" feed lines from the master cylinder to the ABS brick (which we purchased new for an S550) had to be cut for new S197 tube nuts (both were the larger M12 sizes) and re-flared. This wrapped up the plumbing for the brake system and the ABS brick mounting. Next time we will show the wiring for the speed sensors as well as the additional yaw sensor needed to (hopefully) make this work with the OEM ABS computer.

        We want to test the OEM S197 ABS system on this car (to verify that it can work on ABS swapped cars), then we will have found a good, low cost ABS system we can swap onto any car without needing the rare and expensive Ford Racing ABS computer. After we get this tested we can then swap in the Ford Racing ABS computer and retest the brakes with that setup - to see how much better it stops, if any.


        Back in 2020 we had "The Carboning" - which was when a huge shipment of carbon fiber arrived from Anderson Composites & Seibon (sister companies) for several of our cars - including this 2015 Mustang. We have already showed the carbon Anderson trunk going on, as well as their carbon "GT500" hood that was transferred over from my 2015 GT.

        I had honestly planned on adding the carbon doors AFTER we had a full roll cage, but the weight was already creeping up and I threw caution to the wind and since the lightened steel doors had to come off for the dash removal during the heater core install, it was a good time to drop some pounds.

        The door handles and hinges were removed from the steel doors, as well as the stock mirrors and inner release handles. Now we did not add the crash bars from the stock doors, as that involves a lot of surgery and ultimately we want the future roll cage to provide that side intrusion protection. We will likely add some down bars from the main 4-point roll bar as a stop gap solution to this.

        There was a lot of grinding, fitting, sanding and fiddly work getting the mirror pockets in the doors to fit the stock side mirrors. These are hand made doors, so this is to be expected. Doug spent a couple of hours creeping up on the right sized pockets, then both mirrors bolted in and fit snug.

        The doors went on without any fuss - amazingly they fit the stock hinges and opening without any sanding or grinding, unlike other brands of composite doors we have worked with in the past. These fit like OEM parts, which is likely why Ford has Anderson build some of their factory race car carbon parts.

        We have added lots of parts since the last weight check (3060 lbs on 4/1/22) but the carbon doors helped offset some of that and more, with this 3045 lb check (4/21/22). This 3045 weight was with all of the safety gear, both seats, and all of the plumbing. We still lack some wiring work and of course fluids, so a 3100 pound initial race weight is likely.


        Up until this point we still had the original steering wheel installed, but that was never going to see any track use. To get from the stock wheel to the Momo model 88 wheel with a steering wheel Quick Release AND a working horn, took a bit of work.

        I wanted a smaller steering wheel on at this point in the build so we could size and place the digital dash unit. Of course if we are adding an aftermarket steering wheel, and not hoping to keep any airbag or wheel mounted buttons working, we want to add a Quick Release steering wheel hub (aka: "QR").

        Normally we would reach into the Sparco/Lifeline catalog and pick one of their beautiful units - but I did want a working horn, and a thinner QR unit. Having driven recently with an NRG branded QR, I rolled the dice and bought the hub adapter and "thin" style QR from them. Unlike other import QR hubs, this brand has an SFI rated unit - so its better than most.

        To make the horn button work we needed a clock spring, which was missing along with virtually all wiring on this salvage car. So we went to eBay and bought one for $34, $100 cheaper than the Ford supplied unit. Hey, its just for a horn.

        The NRG branded QR hub had a 2 wire pass-thru, which Sparco/Lifeline charge a large up-charge to get. The listing they had for the adapter hub showed "2005-up", but I worried that the 2015-2023 Mustang S550 unit would be different. And it was. I will show below what it took to make their hub adapter fit the S550 with a working clock spring, so we could have a working horn.

        Once we bought the clock spring we had to chase down the steering wheel sub-harness, to connect to the wiring of the clock spring once it was mounted. We found that on eBay and only needed one connector - to connect two wires into the clock spring.

        This is where the "2005-up" adapter hub from NRG needed major modifications. First up, Doug had to mark and drill the two holes in the hub to align with the clock spring pins, otherwise the tunable clock sprung unit would never rotate. Next up a pocket had to be machined into the back side of the hub to clear the clock spring wiring connector...

        You can see the connector on the clock spring, above left. This has to fit within the pocket on the back of the hub adapter. Doug also added a hole for the wiring connector that stays within the hub and sends the wires to the horn button on the Momo wheel.

        Details of the steering wheel harness that normally connects to the stock steering wheel, which has a lot of pins for a lot of circuits. We only need two pins for the horn, and those are being connected, above right.

        The automotive horn circuit is very simple... it is just a momentary button that closes the circuit, that then triggers a relay that runs the horn. And yes, we use horns on race cars - this has saved me from being backed into in grid TWICE. Thousands of dollars of bodywork damage avoided by a quick "HONK!". The two pass-through contacts for the horn circuit are seen on the open QR hub, above right. again, most QR hubs do NOT have wiring pass-thrus.

        We were a bit short on stainless M5 countersunk bolts, so we had a mix of black oxide and SS bolts when mounting the Momo model 88 wheel. I chose the 330 mm version over the larger 350 mm, as it fits my legs and still allows plenty of visibility to a digital dash when looking through it.

        All of that work just to have a horn? Yep - hopefully NRG will see this and make a proper S550 hub adapter, so you don't have to drill and machine pockets into your hub if you go with this brand. But this NRG unit is very low cost for the quality of the actual "release" and connection of this unit, and it is also very thin. Moving the wheel away from your body is much more difficult than when using a spacer to move it closer to you. A thin QR setup is tough to find.


        When we were attacking the steering wheel I noticed that the direct mounted shifter on our Tremec T56 Magnum XL was a little too close to the round opening on the S550 transmission tunnel (the "LS" version of this transmission just dropped $400 in price, BTW!) I asked Doug to open that up and prep it for a proper fire-proof shift boot. You can see below how much he cut away, and it now fits perfectly. No, the normal T56 F wouldn't fit this chassis - it places the shifter 5.5" further forward, which would be buried under the dash. And taking a direct shifted trans and adding a remote shifter to it is so backwards that it hurts my brain.

        Now there is a bigger hole in the tunnel that needs to be covered up, and the rubber OEM shifter "gasket" wouldn't fit - but it isn't exactly a great fire-proof covering for a hole in the tunnel. We want something better in every race car - to prevent fluids, gasses, heat and fire from breaching the cabin from underneath the car.

        I love this Joe's Racing fire-proof and heat repelling shift boot assembly. These are about $125 for the aluminum mounting base + the multi-layer shift boot shown above. This is easy to mount to a flat transmission tunnel like the S550 has, and Doug used 4 riv nuts and bolts to mount the base. The fire-proof shift boot snaps onto the base with 8 snaps.

        Now was the time to clean up the center console plastics, which came with this car fortunately. This stuff was pretty gross but Doug cleaned all of this up with some Armor All and rags. This 8.3 pound unit was then placed into the chassis and we looked at the shifter location with the console in place.

        Well that added some new restrictions to the shifter path up from the tunnel to the console opening. This led to THREE different shifter extensions which were cut on the CNC plasma table, then threaded and bolted to the shifter base in the transmission and the included shift handle from Tremec. These were each made and tested with the console and stock shift boot in place, then tweaked to fit my driving position.

        I will admit that I like a taller shifter, with the knob as close to the steering wheel as possible. But the "S" shaped handle is necessary to allow the shifter to clear the console opening. If you have a gutted interior this won't be necessary, and possibly a T56 Magnum F transmission might fit this swap on a race car. Given enough time I would like to test fit that trans and possibly offer that + the matching driveshaft as an option. Once I drive the car on track we will see how all of this works.


        With the Momo steering wheel in place we could finally mock-up some digital dash cut-outs we made to scale off of 4 of the main AiM dash options. And yes, it is no secret that we would rather choose one of this brands digital dash systems if at all possible, simply from how well their on-board PREDICTIVE TIMING systems work. That one feature makes this brand coveted above all others - the ubiquitous AiM lap timer feature.

        Of their many sizes we have a handful we tend to use on most race cars - the MXG, the MXP and the MXS. There is also a new wide 10" display that comes with their PDM system shown below that we have been dying to try out on one of our builds. This wide screen is full color and has all sorts of LEDs and icons (or not, you can order it either way) and strangely this would fit well within the S550's dash.

        Jason drew these four AiM dash outlines up in CAD and Austin cut them on the CNC plasma table, and these have now been used in a number of cars to size the right unit to fit the dash / driver / steering wheel.

        As you can see below, the tall and narrow units did not fit as well as the low and wide - but we have tried to buy the 10" AiM "PDM" dash many times over the last 2.5 years, with zero luck. We keep trying to get one of these from AiM but we keep getting the "well these should be back in stock in 6-8 weeks", which is code for "we have no idea when these will be back in stock". Real lead times have been in the 3-6 month range for this unit every time we try to order. Since AiM is based out of Italy they got really hammered by Covid restrictions, then this new PDM system had some software development delays, this might not be a viable option for a while yet.

        We're holding off as long as possible to try to get this 10" digital dash unit - but who knows if we ever will? We might have to punt and try another AiM dash or worse - try another digital dash. The Holley Dominator EFI only works with a handful of brands, and if we do a non-AiM display we would have to utilize an AiM SOLO lap timer separately, which is how we've been doing predictive lap timing in my own cars for 15+ years.


        Thinking we would lose some weight by ditching the rear glass, I decided to go with a Lexan rear window a while ago. We got these from a UK company called Plastics4Performance, and they always produce great fitting Lexan that is pre-cut, curved to shape and pre-painted borders. Even with overseas shipping from the UK their parts cost less than domestic suppliers. We love using P4P whenever we can!

        We had Titan Glass (a windshield company) back in the shop in June 2021 and had them pull the rear window, which they got out cleanly and in one piece. Modern glued in windshield and rear glass can be tricky to remove, and tempered side and rear glass literally explodes if you break it - so we let the pros handle removal and reinstallation most times.

        Fast forward to Spring 2022 and it was time to get the Lexan installed. Doug mocked these up in the empty back window channel and they fit perfectly. They looked pretty close on the quarter windows as well, but I decided to hold off on installing these for now - seeing how little weight these actually remove.

        As you can see the rear Lexan window is only 9 pounds lighter than the stock glass window. Hmm, not much weight loss, which is why I held off on the quarter windows. Remember: glass windows are VERY hard and scratch resistant, but Lexan is the opposite of that.

        Doug cleaned out the stock weather strip material and (after the steps below) installed the 1" wide x 1/8" thick, adhesive backed weather strip material we purchased for this install.

        Dozens of M4 rivnuts were installed along the perimeter to mount this window in place. We like to use these Tinnerman countersunk stainless steel washers to make the M4 countersunk bolts fit flush to the surface of this window. Drilling the Lexan is easy with a sharp drill bit, and we leave the outer (blue) film on until after all holes are drilled and counter sunk.

        continued below
        Terry Fair -
        2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
        EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


        • #19

          continued from above

          The final Lexan install looks great, but again, all of this work only dropped 9 pounds. We still like these removable Lexan windows for the rear, as they can be unbolted without breaking the glass or needing special cutting tools, which we needed to attack the rear deck lightening and the trunk bulkhead install. Also, when a Lexan window breaks it doesn't shatter, so that's a plus for a race car.


          I was going to add a full fire suppression system on this car later, to keep the "initial race weight" down (trying to win a bet with a buddy!), but I just don't like taking chances with fire - so a Lifeline Zero 2000 4.0 liter AFFF Fire Suppression System was added before the car ever turned a tire in anger. With as many plumbing and wiring changes made here, this is just smart insurance. The further from stock your race car gets the more likely you will need to use a fire system. We also added one of these to our old red 2018 GT for the next owner in early 2021 - and some of those images are shown below.

          This is the exact same "aqueous foam" system going into our black 2015 GT, and on the red 2018 we mounted the bottle in the trunk, the nozzles in the cabin the same as our '15, and even the engine bay nozzles we well. But we are making some small changes from this point forward. After talking to a fellow racer at PRI in December of 2021 - who had suffered a horrific race car fire fire - we used some improvements based on what he saw. For one, we are changing how we will install the two fire pulls in all cars from here on out. I will pull this section out and make that its own forum post in our "Safety" section, too.

          On the red 2018 GT above, which is still very much a street driven car and track car, we put the two fire system "pulls" in the same places we always used to - one below the headlight switch on the driver's left, and a secondary pull in the center console within reach of the driver. Let's call this "driver-centric placement".

          That was a common way to place fire pulls for a fire system for a decade of more. But in Mark Patronis' Corvette crash and subsequent fire (his helmet above should tell you a lot), the right side of his car was buried in a tree - which was where his only externally accessible fire pull was located. The other pull was in the middle of the car - which was on fire - but he was knocked unconscious. So nobody could get to either fire system pulls, and precious seconds were lost before the fire truck could arrive.

          As you will see below on our 2015 GT, we have started placing both pulls with an emphasis on "corner worker access", with a strapped in driver's easy access as a secondary concern. Hey, you can always grab the fire pull on your way out of the car. Hopefully we can all learn and progress over time to avoid these situations.

          After Jason and I went all over the 2015 GT, and the very crowded trunk area, we found a place to mount the Lifeline 4 liter fire bottle, it came down to the back seat area. Instead of mounting this above the factory fuel tank covers, it looked like this could fit right behind the driver's seat and still allow access to the fuel tank cover. Doug made the domed aluminum sheet metal cover for this side of the saddle tank at the same time as he made this fire bottle bracket, which itself bolted to the rear "cross beam" normally under the back seat.

          The next step in any fire system install is to locate the best places to mount the nozzles that discharge the fire suppressant. Aluminum sheet metal brackets are mounted and the nozzles are aimed at the common fire source locations - a pair of nozzles are aimed at the two fuel rails, where the fuel injectors live. These are also near the exhaust headers, a high source of heat. In the trunk we mounted a nozzle above the remote fuel surge tank, which houses the two fuel pumps and many fittings for the fuel system.

          Inside the passenger cabin we have two nozzles. One points to the passenger's lap and the second points at the driver's lap. These areas are eventually covered in plastic trim, but with holes to allow the nozzles free aim.

          With the nozzles all placed it was time to plumb them from the main tank. The system comes with plenty of aluminum tubing, T fittings, and is relatively easy to connect. These are cut with a tubing cutter then pressed into the quick connect fittings. To remove them, a tool is used to release the locking clamps internally.

          From the bottle one line goes into the trunk to feed the nozzle there, then another goes forward to feed the cabin nozzles and engine bay nozzles. These were routed to fit underneath the center console, with notches in the plastics to fit these without crimping the lines.

          With all of the nozzles plumbed, the final step is mounting the fire system PULL handles. We used to put one in the center console by the driver and another at the driver's side front window front corner - but after hearing about a crash where one side was buried in a tree, we have opted to put one on each side, reachable from the outside but also within reach of the driver (on the left side). You can see the first pull on the above right image, where one of the aluminum panels Doug built fits in place of the outermost air vents. A custom machined bung is attached to this flat panel to point the pull handle at an angle for easy access by a corner worker from the outside.

          This type of placement of the two fire pulls allows a corner worker from either side of the car to reach and pull the fire suppression, even if the cabin is engulfed in flames or one side is buried into a barrier or another car. Now there are other safety measures you can take - like an automated (170F) release, which could help a driver who is unconscious to be safe before a corner worker can get there. I will cover this and more in that separate fire system install forum post.


          I talked to our painter Shiloh about our multi-colored Mustang. Making this car with salvage yard parts and marketplace finds, it was 4 colors.

          The driver's side of the Mustang had black, white, blue and carbon fiber panels. But the passenger side was all black, with the black primer RF fender. It looks a lot better and once we got rid of the steel doors and had carbon doors / hood / trunk, I decided to have Shiloh paint the front nose and front fenders a matching factory black. I took him these panels plus the stock trunk to match the paint to that.

          I dropped these panels off in April and picked them up a few weeks later in May, and it was time to install them for a black and carbon car. I will admit that my original plans were to paint this entire car red but my painter and everyone here at Vorshlag talked me into an all black car, and we can just add graphics for some color.

          Brad began reassembly of the front end by installing both front fenders, which had both been on the car so they fit up nicely. Next it was time to install the newly painted black nose.

          The bumper cover plastics are flimsy but when the grills and lower lip are installed it all "firms up" and takes shape. This is a bit of a fiddly process and it takes 4 hands to get everything popped into place, but once assembled the nose went onto the car - held on at the top by the radiator support and on the sides by the fenders. The headlight assemblies went in last.

          The ride heights on the MCS remote double struts were setup for the 3650 lb weight of the 2018 GT, but with 600 fewer pounds on this car the front ride height needed a big adjustment. Brad lowered the lower collars on the struts and got the front end to drop another inch, now with "normal" fender gaps up front.

          I am not a huge fan of black paint jobs, but changing colors was going to be a LOT of work and a LOT of expense. I'm glad I let everyone convince me to go ahead and paint the fenders and nose - it was affordable and really looks a LOT better than the multi-colored mess from before.


          The temporary 2006 Corvette light build we did "just to get some track time" has fallen right into a great class for SCCA Time Trial called Tuning 2, or T2. After adding some 2 year old 315mm Yokohama A052 "200TW" tires and then some headers + a cold air, its actually won 3 TT events in a row in T2 class. At two of those, it was the 2nd quickest car of the entire event. Nobody is more surprised about this than me! Getting in a lot of test events in this car helped me blow the cob webs out of my driving, but there is more to it than that.

          Why does this matter for this LS550 build? Well the C6 weighs 3117 lbs (virtually the same as this LS550 should weigh in Phase 1) and makes 382 whp, and runs on very similar suspension (MCS RR2), tires (315mm 200TW), but much worse brakes (Z51 2 piston PBR + Mk60 ABS) - yet it has turned a 1:19.702 lap at MSR Cresson 1.7 CCW course, on street tires. That's quicker than we ever ran on 200TW tires on the red 2018 GT - and it did that with 100 whp less than the red car.

          The S197 ABS and 380mm 6 piston Powerbrake setup we have for #Trigger are both much better, race weight should be similar or less, and the stroker LS6 should have +150 whp more than the C6's LS2. This all bodes well for my guesstimated performance of this 2015 GT from day one with fresh 305mm RE-71Rs I have on hand. We shall see soon enough!

          WHAT'S NEXT?

          We are closing in on the last items on the punch list before we attempt "first fire" for the 385" LS6 - when we fire up the engine for the first time. There is a big check list to go through for that milestone, and we will cover that next time.

          Most of what lies ahead is wiring - both chassis wiring and Holley EFI wiring, as well as the main battery cable work (which is nearly done at the moment). We have to nail down a digital dash to use as well - but we have something on hand that might work. Tune in next time to see that and hopefully some video of this engine running.

          Until next time!
          Terry Fair -
          2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
          EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


          • #20
            Project Update for January 25th, 2023: We are now into 2023 but I have been cranking out the forum build thread updates! Several customer cars have been wrapped up and left, our C6 Corvette is pretty much completed all of the testing and product development we wanted, our 2023 BRZ arrived and is already 4 track tests into a detailed modification plan, and the #LS550 swap 2015 Mustang is running, driving, aligned and already been to the dyno.

            We should be on track in a few weeks or less, if I can coordinate the tuner and reschedule more dyno time, but I'm happy with where we are. The Mustang makes glorious noises and I cannot wait to get it on track! Let's catch up on the last few months of work, where Doug and Brad have poured some hours into the final tasks, suspension tweaks, massive EFI work, two digital dash installs (ugh), first fire testing and more.

            Many lessons have been learned on this build - and as always, I want to share those mistakes, misjudgements, and lapses in experience with you! Hopefully I can prevent one of you from duplicating some of the problems we ran into here. If so, then the work in writing this was worth it. Not trying to take your money with some ridiculous "you have to get us to build your car" fake expertise, just a shop owner who has made plenty of mistakes and is not afraid to share them.


            This sentence above might be the best advice I can give anyone on a modern car (2010-up) that you think about turning into a race car. The amount of CAN network wiring in modern cars is staggering, and making any OEM sub-system work without the factory CAN network is daunting. Things like the ABS system, EPAS steering, climate control, factory gauges, or of course the Engine Control Management is extremely difficult and in some cases *impossible.

            (*nothing is truly "impossible", with enough time, money and expertise thrown at it. I mean "impossible" in a practical sense. Some CAN systems we ran into were just not worth the extreme effort / cost / time it would take to make them "work" on our completely re-wired car).

            Why do you want to re-wire a race car? Well... sometimes people say "to save weight" but that's not real. Sometimes to "make things simpler", and I can see that, but you have to know you will lose a LOT of functionality. I bought this car as a wrecked, salvage title car that had been picked over and put together from multiple leftover parts by The Parts Farm in Lyons, GA. They specialize in parting out cars at The Parts Farm, and they took every shred of wiring. What I asked for is what I got, but I wasn't very clear about the factory wiring - it would have been REALLY NICE to have kept the factory harness and sub-systems, then weeded out what we didn't need. Instead we got a car completely devoid of all wiring, fuses, relays and all computers.

            What this lead to was an immense amount of wiring re-work to get the even systems to work as a "stand-alone" system - just having functional brake lights took some work. The S550 Mustang's ABS has not been made to work stand-alone (we tried on another chassis, too), so we swapped in an S197 ABS. The EPAS steering rack was made to work, but we lost some of the factory features. The wipers, turn signals, steering wheel controls, horn and some other systems proved to be so daunting that we have abandoned hope in getting them to work without major loss of features or complete replacement.

            If you are building a 100% dedicated race car, maybe a loss of factory functionality doesn't affect you, but the loss of the factory ABS (which is REALLY GOOD on this S550) should not be overlooked. If you want a "dual purpose" track / street car (like we are building here - to be able to run some "street car" classes) you are going to really miss a lot of the features that the factory CAN System controls. Do not just think you can toss the CAN / wiring / ECU without major downsides. PLEASE THINK BEFORE YOU GUT a modern car of wiring! This loss of CAN systems cost us a year of time if not more - this was the most frustrating and tedious aspect of this build. There was a LOT of work to lose the ~20 pounds of factory computers and wires on this build - again, not by choice.

            CHASSIS WIRING

            There were a couple of weeks spent in the trunk of this Mustang wrapping up wiring, bulkhead connectors, battery cables, the kill switch, circuit breakers, fuel pump and diff cooler wiring systems.

            We had to wire in even basic systems like the cooling fan, brake lights, the horn and transponder, and other basic systems. These would normally be existing in a normal car with factory wiring, but again - we had nothing to start with.

            Watching someone wire a race car isn't exactly riveting reading material, so I will just show some highlights of this work in these sections and focus on the unique things we have done along the way. The Radium remote surge tank has 2 pumps inside and we kept the stock in-tank fuel pump as a lift pump to feed the surge.

            The Cartek GT "remote battery isolator" (remote battery kill) was added to a panel in the trunk, which Brad added a 200 amp main power circuit breaker do. The main battery cable from the Optima yellow top feeds right through this circuit breaker and the negative cable feeds through the Cartek.

            The main battery cable goes through the rear seat bulkhead panel via an insulated bulkhead wiring terminal. We added a Deutsch 20 pin bulkhead connector in this same panel for the smaller wiring to pass through into the trunk as well.

            This round 20 pin connector was added after a rectangular bulkhead connector was maxed out. Always plan your wiring ahead of time and you won't have to go back and add more bulkhead connectors, like we did here.

            Adding this rear seat to trunk firewall was a good idea as we had the Radium surge tank with two fuel pumps, differential cooler pump and other flammable fluids and electrical bits going on back there. This is the trunk wiring almost finished, above. The negative cable goes from the Optima battery to the Cartek kill and then to a big lug on the chassis. If you trigger the Cartek it kills the ground to the battery and shuts down everything.

            Once the battery / Cartek / 200 amp breaker were wired in, the main battery cable was run forward through the cabin to another bulkhead pass-thru at the engine bay firewall (can't find the pic), then routed down to the starter. The starter solenoid wires were run from the Painless Harness and to our push button starter.

            This is just the same LS1 starter we sell for all of our LS swaps, and it works great. Brad wrapped the areas of the cable and solenoid trigger with some heat wrap, as they are close to the header. If we notice it getting heat soaked by the proximity to the ceramic coated stainless header we will add a heat shield around the starter - but so far, so good.

            There are lots of little systems that we have wired in - the AMB transponder, a big loud horn, the brake pedal switch. I will cover the important systems in their own sections.


            Programmable Power Distribution Management or "PDM" systems are all the rage the last 3-5 years in Motorsports. These are used widely in industry (my John Deere tractor has a PDM, and OEM car makers use them also) to minimize discrete wiring runs from every switch to each powered motor. This bundle of wires is replaced with a CAN network that sends commands to the devices, removing a lot of wiring and relays from a vehicle, and allowing some basic ladder logic to control multiple systems - based on alarm conditions or "if/then" logic.

            Sounds great, right? Well - it is! Right up until the point when your PDM takes a dump. I've heard from more than a few racers that they always keep a 100% backup PDM on hand for critical race weekends. Instead of a spare relay or switch, you need a spare PDM! Still, the desire to have this build on "the cutting edge" of PDM hotness inspired me to order the AiM PDM32 system. Twice.

            After TWO YEARS of waiting for two orders from AiM Sports for PDM systems, starting back in early 2020, we threw in the towel. Each order we sent them was ignored for 6+ months and every time we asked for an update it was "8-12 weeks" out. We cancelled both orders and went another route. AiM Sports, being based out of Italy, had MAJOR supply chain and remote employee work issues getting these new PDM systems launched during the Global Pandemic. Even now in 2023, fully THREE YEARS after this new system was announced and released, they still have very real problems. I do not recommend going this route, for now, until more racers / guinea pigs have helped AiM work out the bugs in their PDM. And with a Holley, well... none of the display would have worked anyway.

            Instead of waiting years longer, we ordered this harness from Current Performance. This "mini PDM" was a $225 unit made specifically for the Holley EFI system we are using. This can control 2 Fans 2 Pumps plus an auxiliary system. Pretty basic but it is a programmable "PDM" in the strictest sense of the definition.

            We used one Fan control for the main radiator fan, the other for the diff cooler pump and fan, and the two fuel pump circuits control the two main pumps inside the Radium surge. We had the lift pump on the "aux" circuit but removed that and run that separately (some programming issues cleaned up and we will move that back). It communicates directly with and is controlled by the Holley Dominator ECM - which we have mounted right below the Current Performance box.

            Brad modified the panel in the glove box area we built to hold the Painless Wiring harness' main fuse/relay panel. This is thru-mounted in this panel for easy access to the relays and fuses, for easier maintenance.

            This little mini PDM worked perfectly when we fired up and dyno tuned the car, with the exception of the lift pump. Again, some programming changes should get that cleared up. All of this is hidden behind the glove box door, with the rest of the Painless harness and Holley ECM. And yes, there is an LED light that can be switched on (with the "dome" light circuit), to make maintenance even easier.


            One small oversight when the Accusump was installed - we didn't order the Canton triggering solenoid. This is what electronically "dumps" the pressurized cylinder into the engine's oiling system.

            This large 3 quart Accusump unit barely fits between the frame rails so adding this solenoid to the end wasn't possible, but Brad built a bracket out of some 1/2" thick aluminum plate. This was shaped to fit against the frame rail and drilled it to fit the bolt spacing on the solenoid.

            This was then mounted remotely and will be triggered by the Holley EFI system or manually from a switch on the center stack dash panel. The Holley EFI was programmed to release the pressure when the engine is running above 2000 rpm and oil system pressure is under 20 psi. Simple, safe, let's go.

            continued below
            Terry Fair -
            2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
            EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


            • #21
              continued from above


              Another OEM system we lost with this "CAN-free" car was the Electric Power Assist Steering, or EPAS. The 2011-14 S197 and 2015-up S550 models all went to EPAS, removing the hassles and dangers of hydraulic power steering pumps / lines / coolers.

              This car has a junkyard sourced 2015 Mustang EPAS rack. We then purchased a "stand-alone" harness for the S197/S550 racks from Cortex (the blue/white wires coiled up inside the big red/black cables), then a power harness for this from a late model F150 (the outer coiled cables). This Cortex harness has some sort of circuitry to "trick" the EPAS rack to work without CAN signals. We lose speed input changes and the dash-mounted 3-mode selections using their harness, but I don't really care or notice.

              The image above left shows both connectors - the control and power harnesses. The main power cable (#4) is fed from the power distribution through a 100 amp circuit breaker before going to the rack (see above right).

              All of this works like a champ - I made a demo video last week, which shows how this works, even with the engine off. This is handy when you are pushing a race car around. We just power on the Cartek kill and - VOOM! - we have EPAS.


              We don't have the factory HVAC controls or radio - which is what takes up a majority of the center part of the dash. I like to call this the "center stack switch panel", and it is valuable real estate in most race cars. If the driver can reach part or all of this we can add buttons, switches and dials. We started with a cardboard template that Brad cut out, then I scanned that for a CAD version that Jason would ultimately create based on my layout.

              For the Center Stack Panel on our Mustang, I wanted to spend a little more time on, really get this dialed in correctly. So many times on race car builds the center stack is a flat panel with switches, dials and ports added over a long period of time without any real long term planning or "cohesive plan". This area adapts as things like a cool suit or new systems that need switches get added (see below left).

              I also wanted to use a type of rectangular paddle switch that is common in trucking, marine, and lately race car use. These come in 2 position, 3 position and even momentary push button versions, and can be backlit. I had a gaggle of these I got stuck with on a customer's build he flaked out on, so we had some initial switches we could start with. Long term I will get these custom made with laser etched lettering and symbols that are backlit, but these will do for now.

              These rectangular holes are a REAL CHORE to cut out manually, so we created a design in CAD that we could cut out quickly on the CNC plasma table. Brad and I planned out the switch placements early on, along with some additional items: a 7" LCD screen (for a back up camera / lose cam), some USB ports, a digital volt meter, push button start, Cartek main battery kill switch, AiM remote memory card holder, and a control panel / readout for a driver cooling system that would we added later. We also had a comms port for the AiM dash.

              Getting the shape of the panel to fit the center stack opening on the S550 dash took a couple of iterations, as did the final sizing of the rectangular switch openings. We also changed the layout of a few items after mocking them up in the car - with me strapped in the driver's seat - after finding the limit of my reach. The 4th version was just about perfect and Brad got that one painted up.

              To mount the center stack panel into the dash required some custom brackets, which themselves adapt to the radio mounting area - which is further back and at an angle. Brad whipped these out and bolted them into the partially gutted dash structure. Later on the mounting holes to these brackets was added to the CAD file for the panel, to make later iterations quicker to mount up.

              Once we had the layout right Brad wired in the various switches to a DW multi-pin connector, so the whole unit can be unbolted and removed quickly. As you can see above left there is a lot going on behind this panel, but the finished unit (above right) looks clean, purposeful and well thought out. Later on as we add more systems we might need another version but I think this one will last us a bit.

              Brad also created a lower mounting bracket at the bottom of the opening, then a horizontal filler panel that that ties the bottom of the center stack panel to the lower console - fills in a section that is normally a plastic storage cubby. And that big blank section at the bottom of the panel is for the driver cooling system controller, which we will add later (basically an air conditioner for water that will go through a driver worn cool suit).

              This is the completed center stack switch panel, along with the functional 7" LCD screen for a back up camera - which has been surprisingly useful on this car! I use this in my street car daily drivers, and every single time I back up this Mustang it gets used. With Halo style racing seats and a HANS device on this will be a welcomed addition for visibility behind. I bought this screen ages ago and I think it was about $50. The license plate frame with included camera and LED light was about the same amount, so for $100 we have a useful addition - an more D&E points for Optima, haha!


              This section of the project was an unpleasant surprise - which we learned about after the fact - Holley doesn't support any other aftermarket digital dash. AiM Sports made it sound like they worked with Holley HP and Dominator EFI systems, so I purchased an AiM MXG dash, but that was a lie. There is a nerfed Holley output that supposedly works on RacePak digital dashes, but you lose ~75% of the Holley data channels with that protocol.

              We spent a chunk on this AiM MXG and the remote SD card holder, and spent a chunk of time mounting it all - all for naught. I really like AiM dash units because they (can) log data and I am familiar with their data analysis software. These units also have an industry leading lap timer and predictive lap readout feature. Words cannot describe how pissed off I was at the end of this section of work to realize that we HAD to use a Holley dash...

              I will show the steps where Brad made the mounting brackets and panels - because we re-used all of this to mount the Holley digital dash. I wanted the steering column plastics installed, to keep the interior looking "finished" for a few racing classes we had in mind. The trimmed hole above fits the AiM and Holley screens.

              I had purchased missing items like the factory gauge bezels, then Brad made a "gauge block off" panel starting with cardboard and going to aluminum. Sections of the angled and round bezels had to be modified to fit this blanking panels.

              Mounting brackets for the blanking panel were added inside the back section of the gauge bezels, then the AiM dash template was used to transfer the mounting holes for this screen.

              I was happy with the finished install, but very UNhappy to learn this screen won't work with any Holley EFI system. I will use a remote AiM SOLO lap timer for use on track for now, but that is more clutter on the windshield I was hoping to avoid.

              We're not giving up all hope, however, and have a CAN integration specialist working on a custom box to help the to devices talk together. Its much harder than just "sniffing the CAN signals", but I will cover this in more detail next time - if we can make this work.


              One of the things that can happen when you have a LOT of sensors and data displayed on a digital screen is DATA OVERLOAD. So we have some warning indicator LEDs we planned for and I purchased. These cover things like low fuel level and ABS warning lights, but also left and right turn indicators, high beam lights, and even Reverse light indicator. These have already proven useful in testing.

              I purchased 6 of these units online at $8.95 each and Brad got to work on the layout and placement of each, testing with me in the car for each one.

              These all are wired into another DW 12 pin connector for easier panel removal and work. The first one to be wired in was the low fuel indicator from a level switch in the top of the Radium remote surge tank. This was an optional item when purchasing the surge tank and lets you know as soon as the tank goes from "full" to just a bit under - which means you have about a liter of fuel left. This is a "BACK OFF THE LAP AND PIT RIGHT NOW" light.

              We have also added a Reverse solenoid controller and when the transmission is shifted into Reverse the "R" indicator on the dash lights up. We have 4 other indicators that we will wire in as time allows, after the dyno testing is complete.


              By Mid-November 2022 we were ready to start adding fluids and bump the starter, crank the engine, and check oil pressure. This would also be a full plumbing system leak test.

              I decided to use a Motul break-in oil for the first dyno test, which we would change out for proper Motul 5W50 Ester synthetic before the first track test. We needed THREE GALLONS of oil to fill the oil pan, filter, oil cooler and Accusump.

              We filled the cooling system with distilled water and a touch of anti-freeze. We used a cheap AC Delco DOT3 hydraulic fluid for the brake and clutch systems - anticipating some small leaks, which of course did happen. This will be flushed and bled with proper Motul RBF600 or 660 once the initial dyno work and test driving is completed.

              Filling the diff cooler system was a challenge. We had a "T" fitting high up in the system with a cap, just for this purpose. But since the cooler was above the diff housing, we would have to do a calculated fill. The pump acts as a check valve so once fluid gets pumped into the cooler is stays there (again, this is by design). We had to run the pump to get everything full, until it was coming out of the top hole (the normal fill line). Then added the amount that goes into the cooler. Doug used a long funnel and added the 3.6 quarts of Valvoline 80W90 diff fluid (Motul Gear300 was out of stock globally) and some Auburn Gear limited slip additive.


              One of the things Brad noticed when he want to add some sensor wiring was that the Aero fuel pressure regulator was in a tough spot to reach and had some plumbing that got a little to close to the exhaust header. After looking at this closely I agreed and set him loose.

              After making a new bracket he relocated the regulator, re-routed the hoses, and made one new Fragola hose. That keeps the regulator as far away from the headers as possible without putting it too far from the fuel rail to be useful.

              We had somehow missed adding a MAP sensor, so we ordered the correct LS6 style from AC Delco. There are two options for the one O2 sensor on a Holley - NTK or Bosch. We also ordered and installed the wide band Oxygen sensor, the NTK "0.9 Lamda" unit (for NA engines), from MAD Racing.

              FIRST FIRE TESTING

              All sensors were installed and wired, all fluids filled, now the battery was charged up. The starter had been bumped several times, even cranked, to fill fluids into the oil system.

              We took the start-up tune from our tooner and Doug loaded that to the Holley ECM. We added fuel and cranked... checked fuel pumps, checked spark plugs, but it would NOT start.

              We had to triple-check major sensors, like the crank sensor. We verified that I had ordered the right 58X reluctor sensor and that we had a 58x reluctor on the crank.

              We were getting weird faults and then checked the distance from the crank sensor to the reluctor wheel, using a socket, marking the depth and checking against the sensor. That wasn't it.

              After a two days of testing, checking, new tunes, phone calls and more cranking we found the issue - the Holley ECM will LOSE THE TUNE sometimes when the battery voltage to the computer dips below 10V when cranking. And sure enough, the battery would drop nearly 2 volts cranking (see above images) and we had to reload the tune and re-run the TPS setup wizard. This isn't a bug its a FEATURE, haha! (this is a MAJOR bug Holley... major).

              On November 18th, 2022 we finally figured out the "tune disappeared" mystery and got it to fire up, which you can see in this ugly video. We still had a massive vacuum leak and the idle was high, but that was found later and the idle RPM calmed way down. We needed to bleed the brakes and clutch systems, but hearing the engine run was huge.

              SPL PARTS REAR ARMS

              If you followed our 2018 Mustang GT development thread you know that we had some of the earliest SPL Parts for the S550 Mustang on that car. We are an early tester stuff for their parts, and I know Sean and Turner from that company well - they are the current NASA Texas Time Trial directors and TT racers we see on track.

              They sent us these upper rear control arms right after they went into production in 2022 and they look amazing - even with a schlub like me "modeling" them. Gorgeous parts they design in-house and have machined here in Texas, with some parts on their own CNC machines at their new facility. I was more than happy to test these out on Trigger!

              It didn't take Doug long to swap out the stock, heavy steel upper arms for these new adjustable units. This will allow us to finally get more than -2.2 degrees of rear camber! (We ended up at -3.2 deg when it was aligned - see more below).

              continued below
              Terry Fair -
              2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
              EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


              • #22
                continued from above

                I like this feature above - the O-rings installed around the spherical bearings will help keep water and grit out of these metal bearings. This is even more important once you get sphericals near ground level. After that was rough adjusted (we had an alignment scheduled soon) you can see all of the many SPL parts we have in the back of this Mustang. Only the lower control arm is stock - and we suspect an SPL replacement will be coming along eventually for that.


                One of the last mechanical "challenges" we had before we first test drove the Mustang happened when bleeding the clutch. But to get to that point we had to order and install a stand-alone clutch reservoir (see below left), which we sourced from a C5 Corvette. This was mounted to the firewall and allows for a separate source of fluid for the clutch - instead of commingling that with the brake fluid. Segregated clutch fluid reservoirs are always best. We also finished the main vacuum line from the back of the manifold to the Mustang brake booster (see below right).

                As I mentioned in a previous installment, back in 2020 I decided to re-use a clutch I had "bought back" from a customer after only a couple of days of use. It was a brand I trusted (ClutchMasters) and I even drove the Camaro it was installed in, and liked the feel. Would this make for a daily driven perfect clutch? Maybe not, but for what I had in mind the "weight / feel / cost" was perfect.

                The entire clutch + flywheel assembly was 27.2 pounds - which is a good balance between uber-light 5.5" or 7.25" dia race only "on off" 2-3 plate clutches and stock dual mass flywheel 11" diameter versions. This twin disc ClutchMasters 850 series clutch kit came with an aluminum flywheel, pressure plate, the clutches and the associated hydraulic throw out bearing (TOB) slave.

                Two key steps were missed during the install back in 2020 - the first one being MEASURING the thickness of the clutch and shimming the TOB to have the correct gap from the pressure plate fingers when released (clutch pedal out), which helps keep it from over-traveling to disengage the clutch when you press the pedal in. Once it was out we noted that there were zero shims - I should have noticed this when it went together, but I missed it.

                PRO TIP: Whenever you are installing any clutch into any car and it is not a 100% factory stock single disc with stock slave, DO THE MATH. Every clutch manufacturer has a worksheet and often some simple template tools to help you get the proper throw and setup depth. Measure, calculate, and know that you have the right stack-up height on your slave. avoid this mistake - it only takes about 10 minutes to measure and shim the TOB!

                When Doug and Brad went to bleed the clutch hydraulics, the clutch wasn't disengaging properly - the pedal had to travel too far to release, but this is hard to realize when bleeding. They had assumed that this had been checked and shimmed previously. - to fix this you need to remove the transmission, measure, then re-shim the TOB slave.

                But our luck kept turning south - during the bleeding process, after the suction bleed didn't give a good clutch pedal feel, it was time to use the remote bleed hose and manually pump the pedal and release the bleeder, using a 2 man bleed operation. Pump and press the pedal, release the bleeder, close it off, release the clutch, repeat. That's when The second mistake popped up - not having an adjustable clutch pedal stop - and into the bleeding process the slave cylinder over-traveled and blew the seal out...

                PRO TIP: Whenever you do not have a 100% stock pedal assembly, clutch / pressure plate / slave (like this car - a GM style clutch in a Ford Mustang with aftermarket clutch and slave!), do yourself a favor and build or buy a clutch pedal stop! Then adjust that to allow proper disengagement and NO MORE pedal travel. Over-traveling a clutch slave can blow the seal out, like we did.

                When we had first purchased this clutch in 2017 the TOB slave was 2 pieces - one of which was an adapter that bolted to the T56, the second piece was the hybrid slave / TOB. It was thicker than the new version we ordered to replace it with. The 2022 version was 1-piece and much thinner, and needed to be shimmed to reach the pressure plate fingers. Doug did the math and got the new unit shimmed properly with the new clutch slave.

                We had to create a clutch stop for another car (CTS-V) recently, which had an aftermarket clutch master with a stock pedal assembly. On that mess - which was supposedly "working fine" before it came into our shop - it had blown out a Tilton clutch master. We had to re-align the replacement Tilton because it the pushrod from the pedal was way-off-axis from the master. At least on the Mustang here we could reuse the Ford clutch master, so we wouldn't have to mess with that potential issue. But the pedal stop we made on that car was needed on the S550.

                I sketched out a simple bracket for Doug and he built it quickly from some 1/8" thick steel sheet. The back of the bracket was bent to fit the very non-flat firewall shape, then mocked up with the pedal (which has massive travel).

                That was then removed from the car and drilled for the adjustable stop. An M14 nut was welded to the back side, then an M14 bolt and jam nut added to the top side. A pair of rivnuts were then added to the firewall and the bracket painted, bolted in, and adjusted to have enough travel to completely disengage the clutch.

                The clutch system was then bled and the pedal stop adjusted with the car on the lift. When the clutch pedal was pressed in and the wheels stopped spinning, then the pedal stop was adjusted to only allow a tiny bit more pedal travel. This prevents the over-travel situation that blew the seal out on the last slave cylinder. When driving the car you don't even notice the stop, but it just cannot over-travel.

                A few weeks later the replacement seal arrived from ClutchMasters, which a FB friend noted was available from them for only $12. Money well spent, and Doug had the old 2017 slave cylinder rebuilt in a few minutes - this will be our spare slave cylinder in case we somehow lose another.

                With the working clutch we could finally test drive the Mustang for the first time! I drove it out of the shop and around our parking lot a bit, but a high idle kept me from going too far at that time (mid-December 2022). We brought the car back into the shop to diagnose the running issues and work on some other final details.

                ​​FRONT GRILL DUCTING

                While we waited the ~2 weeks for the new CM clutch slave cylinder to arrive, Brad tackled the task of ducting the front grill openings to all of the coolers.

                This ducting wasn't 100% necessary for the dyno tuning, but it really does help a lot when on track + when the electric fans are running while traveling under 40 mph. Ducting is actually pretty critical between the grill openings and the coolers - air will always take the path of least resistance, and if you allow air to go around the coolers, much of it will.


                As always, Cardboard Assisted Design was utilized and after the cardboard was cut to fit around the intricate shapes, Brad transferred that to .063" thick aluminum sheet.

                The four main "duct box" pieces were cut, corners bent, the various shapes fitted, and cleaned up with a file and finger belt sander.

                A new and better upper radiator bracket was built at the same time - we didn't like an earlier version, so Brad did this thing of beauty, with dimpled dies added. And you won't ever see it.

                At this point the duct box was held together by Cleco fasteners and we were ready to get it final bolted and sealed up. The front bumper cover and front crash beam had been on and off several times to check fit.

                Now the front tubular bumper beam we had built went back on and the panels were bolted together - with simple nuts and bolts. The fit from the front grills to the duct box panels is exceptionally good. Probably better than most racers would bother with, but like me, Brad is a perfectionist. Why just make it, when you can make it RIGHT.


                Lastly this series of panels was built to tie the front left grill opening to feed the cold air filter box. This forces air into the air filter box cleanly, and the back of the hexagonal grill was modified (above right) to open up the entire area for airflow (in stock form this is only about 1/3rd open).


                The two Fragola -12AN oil cooler hoses pass through the cold air inlet opening, but that was the safest hose routing and won't impact performance of the engine. After these final air inlet panels were covered in DEI gold foil, the front bumper cover went back on and the ClutchMasters TOB arrived (shown above).


                We had been desperately trying to make the ~$2800 AiM MXG digital dash to talk with the Holley, like AiM and others have said works.

                We went around and around, triple checking CAN settings in the Holley software, configurations, firmware versions, and on and on. The "Racepak" CAN config in the Holley Dominator system is just one big fat lie - the AiM folks made excuses but they do NOT have a working config for Holley CAN.

                I was pretty angry at this point, and was tempted to chuck the entire Holley EFI system altogether and start over with another brand. I know this - I will NEVER use another Holley EFI in my life, not after this. Starting over now would add months to get to our first track test.

                Cooler heads prevailed and we borrowed a Holley digital dash from former Vorshlag technician, Even at Pure Performance. He had a Holley 7" LCD dashes new in box and said I could borrow it for as long as we needed. It is roughly the same shape as the AiM MXG so it wasn't hard to swap them out.

                We tested the dash while just wired in, and it worked immediately. It seems there is an encrypted CAN handshake between a Holley ECM and Holley dash that nobody else has figured out. Brad got to work and added new mounting holes in the gauge delete panel he built, and the dash was mounted in no time.

                Some of you might think - "hey, it works and its 1/3rd the cost, why not just use a Holley dash?" Well there are several down sides to their dash, namely it doesn't log (the AiM dash does). But mostly the AiM has built in lap timing and predictive lap timing that is world renowned. I'm not giving up on the AiM dash, and we started working immediately with a CAN integration specialist on making a "black box" to help the AiM and Holley systems communicate.

                He told me to order this PEAK brand CAN sniffer, which I did. It arrived a few days later and we built a serial cable to connect that in series with the Holley CAN network.

                We made several 3-5 minute engine running sessions, where we logged the Holley data on the ECM and the CAN data going to the dash via the PEAK sniffer. We are hopeful that someone can create a new product or AiM configuration that works. I am NOT happy about this "Holley EFI only talks to Holley dashes" limitation.


                Up until now we had the reservoirs zip-tied to a lower bumper cover bracket, but it was time to move these into the trunk area. I wanted to be able to access the compression knobs quickly, but the canisters needed to be kept away from heat.

                Doug took a simple sketch I made and built these reservoir brackets from aluminum sheet. It is more than the bare minimum needed, but I want to make sure when I pop the trunk that you can see the spendy bits!

                Each side of the trunk is different, due to the filler neck on the left side, but Doug managed to make the canisters sit symmetrically - which pleases my ACD mind a bit. Yes, the mufflers are still open to the trunk, but we will make a lightweight metal cover for these before we run SCCA Time Trial Max1 class (which requires a "cover").


                On January 5th, 2023 we had many of the above mentioned problems sorted - the car runs and drives, the clutch hydraulics and pedal stop were working, and we had the brakes bled. The SPL rear upper arms were added and the car now BADLY needed an alignment. But first it was time to set ride heights and corner balance the Mustang.

                Brad took the measurements I wanted and set the ride heights, then got a weight. It weighs more than I had hoped at 3256 lbs, but that is "ready to race" with all fluids and fuel in the tank. We added 175 pounds of ballast for driver weight and he got the corner weights to 50.5/49.5%. That's good enough for now (we still have a few things we might change) and we will re-work this before it goes on track.

                Brad took the measurements I wanted and set the ride heights, then got a weight. It weighs more than I had hoped at 3256 lbs, but that is "ready to race" with all fluids and fuel in the tank. We added 175 pounds of ballast for driver weight and he got the corner weights to 50.5/49.5%. That's good enough for now (we still have a few things we might change) and we will re-work this before it goes on track. Some people ask me all the time - why doesn't Vorshlag own a laser alignment rack?

                continued below
                Terry Fair -
                2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                • #23
                  continued from above

                  Well I can give you 100,000 reasons. Cost for a good alignment machine plus a proper 4 post rack ranges between $20-100K, and we stopped taking in "customer day work" 5 years ago. We could never justify the cost, so about once a month I haul a car to a nearby motorsports shop that does proper alignments. It gobbles up time (2 round trips @ 2 hours each) but its cheaper than a hundred grand. And with these multi-link rear suspensions, string aligning becomes a REAL chore that gobbles up 3-5 hours and is never quite as accurate.

                  I drove the car around the shop a bit getting it over to the trailer - wow, the toe settings at both ends were JACKED, it was crab walking sideways a a lot. But I got it winched into and strapped down in the trailer. Adding the front tow hooks makes the front SO EASY to tie down.

                  On January 9th I drove the ~45 minutes over and unloaded at BSP Motorsports, then gave them my "alignment goals" print out, which we do for any alignment shop. They got to work and the next day they had it all sorted.

                  As I mentioned, our initial settings on the camber and toe settings were way off. But BSP worked their magic and adjusted the front camber to -4.25 deg, the rear to -3.2 deg, and the rear toe-in that I wanted. They also followed my instructions by adjusting rear upper SPL arms in a way to maximize rear tire clearance, and up front getting the tops of the tires tucked in by juggling the camber plates and lower arms. Perfection.

                  This makes the 19x11" wheels look downright TUCKED on the back, and the front tires are also well inside the stock fenders. We won't keep the stock fenders for too long, but for now we won't have to worry about any tire to fender contact. This setup just looks aggressive - I'm so ready to get this car on track! But we have some work left...


                  As mentioned above, the S550 Mustang ABS doesn't work "stand-alone" yet - there are necessary CAN channels from the chassis and stock ECU that are needed. Some CAN wizards we know have tried to crack this puzzle, and we have got a number of these S550 ABS units in the shop. When time allows we will try to work with one of the CAN experts to conquer the S550 ABS swap. For now, we have already made a late 2011-14 Mustang S197 ABS swap work stand-alone - using the ford Racing ABS computer and custom tone rings on this C5.

                  This C5 stops better than any Corvette I've ever driven, and we're now trying to make this S197 swap work withOUT the rare Ford Racing ABS computer. We've also done Mk60 BMW ABS swaps, but that is much older tech (circa 2003) and the more modern the ABS, generally the faster it can cycle and the better it can work. The S197 system from 2011 works VERY well and we will move forward with that ABS swap on our S550.

                  We already built an S550 stand-alone ABS wiring harness when we tried to swap one of these onto our C6 (it was a total bust). But we can re-use much of that harness for this S197-to-S550 ABS swap (above left). For this S550 install which has zero CAN wiring we need to add a brake pedal position switch (above right).

                  One thing we are testing with this S197 ABS install is adding the OEM airbag sensor box (above left) to the tunnel, which supposedly allows these 2011-14 S197 ABS systems to work stand-alone without the Ford Racing ABS computer. Since those Ford Racing ABS computers are out of production and getting rare, this is a worthwhile detour to test. If it doesn't work we will stick the racing module in - we know that works. Brad wired that in following a late S197 wiring diagram, and the sensor box sits on the tunnel just like it does on an S197 - hidden under the center console.

                  Next up it was time to wire in the four wheel speed sensors, which are each two wire twisted pairs that run to the factory S550 sensors at each corner. These come from a plug at the S197 ABS unit in the back left corner of the engine - again, mounted in the same orientation as it is in an S197 (see previous entry showing that).

                  To power the ABS system requires two high amp fuses - a 30 amp for the ABS valves and a 40 amp for the ABS pump, per the factory manual. To make room for those Brad built this aluminum bracket and mounted those + a 30 amp headlight fuse + two relays that were already mounted nearby. All of this sits above the 100 amp circuit breaker for the EPAS power harness.

                  The ABS system had been plumbed before just by re-flaring and bending the four S550 factory brake lines and two (big bore) master cylinder feed lines. But the lengths for the two feed lines from the master to the ABS brick were a bit short and had some extreme bends to fit - making for a less than perfect seal. These had been weeping a small amount and I wanted them replaced, so I sourced some 5/16" steel brake hard lines from our local Pirtek supplier.

                  Brad re-made these two fat feed lines from the master and bent them with some extra length to avoid the shortened bends from before. Strangely the two factory S550 feed lines were of two slightly different sizes but made for the 5/16" fittings, which we re-used from the S197. We will keep an eye on these, but so far these have held pressure after being bled that day. We need to test the ABS system soon, but the car needs to be running better before we tackle any test drives.


                  While we were getting ready for the dyno test I asked Brad to go ahead and install both of the "remote" battery kill buttons for the Cartek. The main kill button and the master RESET is in the center. There are good reasons to place the remote battery kills and fire pulls like this. Namely, a corner worker on either side of the car can hit the battery kill from the two red remotes.

                  This matches up with the same dual Lifeline fire system pulls, also mounted for easy access from either side. I can reach the left fire pull from the seat, but more importantly I can hit it as I'm bailing or after I have exited a burning car.

                  Another late update was to the 3rd brake light - which was broken by the salvage yard folks when they stripped this chassis. It was slapped back in place but the circuit board was ruined, and luckily I found a Dorman replacement for around $55. We had also ordered this 3rd brake light module from a trailer towing place many months early to make the 3rd brake light work - as the brake lights are also the turn signals, and it needs a little logic to work correctly.

                  Brad mounted that in the stock location, which the P2P Lexan window was cut for. He wired that in with the truck/trailer 3rd brake light module, and it worked great. A working 3rd brake light is a "street car" + safety thing, and a nice little feature on this totally re-wired car. We still have front lights and turn signals to tackle, but I can drive around safely like this, at least.


                  One other small detail I wanted to fix was the missing cowl cover - we had one from the original salvage car, but the new placement of the Canton remote coolant reservoir and the C5 Corvette remote clutch fluid reservoir made this not fit.

                  Brad mocked it up a couple of times and trimmed around those two items, then cleaned up the cuts with a 3" Scotch Brite wheel on a die grinder.

                  Then the faded black plastic was cleaned up with some Mothers Back to Black liquid, and the roughest parts were scuffed with a light wire brushing. Not only does having this panel look more "street car" having it in place keeps airflow form going out of the back of the hood and instead through the hood vent - but we will see how this works. On the 2018 Mustang with this hood we had some "flutter" at the back of the hood at speeds approaching 150 mph - COTA - and took it out to calm down the carbon hood.


                  The mock-up shift handle we showed in a previous post was only meant to be a template for something better - but we forgot about it and I drove it several times like this. With the reverse lockout solenoid not hooked up you had to REALLY push the handle sideways to get it into reverse, and after a while the 1/8" thick shift lever bent. We needed to turn this template into a thicker, stronger, finished shift arm now.

                  I asked Doug to take the final temporary arm out and modify the design a bit and create one out of 3/8" steel plate - which should be much stronger and no longer bend when going past the Reverse solenoid spring.

                  Once the 3/18" version was completely cut out and threaded for the Magnum XL's included vertical handle portion, it was cleaned up and bent in the hydraulic press brake to have an offset towards the driver. This will allow the handle to function better and clear the small-ish opening on the plastic factory center console.

                  The Joe's Racing Carbon-X shift boot base was bolted to the console last time and the flame proof boot installed. The Tremec shift ball was adjusted for height and the ergonomics fit me better than before.

                  With the Joe's boot in place we at least have a seal from the tunnel's fumes and potential fire, but it doesn't look "street car". The factory shift boot constrains the movement of this shifter so we are working on a custom boot and mounting ring that I will show in a future update.


                  Not having the factory body control module to "open the reverse shift gate" (which is actually a solenoid that you can PUSH past), its a real chore to get the car into reverse. This module that the guys found uses a speed sensor input from the Tremec and can open the Reverse solenoid when speeds are under 5 mph.

                  Brad added this module behind the center stack panel (above right) and wired it into the Tremec with the included connectors. And now this $99 kit is going onto every race car we build - so easy and so fool proof. This also triggers the "R" indicator on the dash, to let you know when the Reverse switch is triggered in the transmission - and will eventually drive the reverse lights out back.


                  The HVAC on this car is pretty simple - the heater / fan box we showed before feeds the defroster and ONE of the three dash center vents. I can close that one off unless its a really cold day and maybe I want to warm my hands while in grid. The other two vents were removed and I always planned on some discrete gauges going there. We finally found the needed data and the right gauges for the job.

                  We need a fuel level gauge and a diff fluid temp gauge, as those are both pretty critical. I also wanted to be able to log this data, and I found these full sweep discrete gauges from Classic Instruments. This is now a Holley company (groan) but these 2-5/8" diameter "Autocross" series gauges do everything I want - they are programmable for the sensors you have (fuel gauge), have two colored warning back lights (red and yellow, see below) that can be programmed, and they also have a 0-5 volt output that can go to your data logger (Holley ECM in this case).

                  Once the gauges arrived Brad got to work mounting, wiring and programming them. Making them fit the two center vents was relatively easy, as these 2-5/8 units just needed some 1/8" weather strip foam to seal up against the cylindrical openings in the dash panel. Brad also modified the clamps to fit the dash pod shapes.

                  He wired these in with a 12 pin DW connector for easier removal, of course, and moved the functional heater vent to the right. This makes it easier to see the fuel level and diff temp gauges, close to me. The programming button for each unit (for various functions) was mounted just inside the glove box door, as shown above right.

                  We need to remove the left side fuel tank's level sensor to program the Ohm range for the fuel level gauge, but the diff temp sensor was swapped into the housing to replace the cheap ~$50 Glow Shift gauge and sensor from the 2018 GT. These are closer to $200 gauges, but the additional functionality and 0-5V output signal is a game changer and worth the up-charge.

                  FINAL PREP FOR DYNO TUNING

                  By January 17th we were ready for the dyno tuning day I had scheduled at LG Motorsports. They have a 5 hour Saturday schedule and I rented their Dynojet for the day, hoping to tune both the S550's HPR built 385" LS6 and my 2000 Silverado truck's HPR built 347" LS1 engine. The engine was running a bit rough so we installed a fresh set of NGK TR6 plugs into the engine right before loading into the trailer, and that seemed to help. They looked "very rich" but we only had a start-up tune in there, and had just fixed a big vacuum leak, so that might explain it?

                  This time it drove a lot better getting to the trailer, with the alignment squared away. I left the 4 year old 305mm Bridgestone RE-71R tires on the 19x11" wheels, as I had panned to do some ABS testing after dyno tuning, and wouldn't mind a flat spot on these throw away tires.

                  I was so excited for our January 21st dyno tuning session for the S550 and my truck, and across town at Dotson Tuning they would be tuning the 2010 Mustang with a Gen-2 Coyote swap that we had finished late last year. So pumped!

                  WHAT'S NEXT?

                  I finished writing this right after the 1/21/23 dyno test at LGM and things, well, didn't go to plan. We chased issues all damn day - Doug and I changed plugs, moved the O2 sensor, checked for exhaust leaks, changed strap points for the dyno and more - that ended up being traced to two bad plug wires. The custom length plug wires we built for the remote mounted coils were popping off. Long story short, the engine made 409 whp on 6 of the 8 cylinders. So first thing Monday morning I ordered a different brand of plug wires which I will personally test on each plug - this won't happen again. Long, expensive, fruitless day. At least the 2010 Mustang made good power!

                  Next time I will go into more detail from that frustrating dyno day and hopefully soon the SECOND tuning day where all 8 cylinders fire. Then it will get a fresh set of A052 tires installed with the 18x11" Momo wheels and off to the track we go for our baseline lap tests at MSR Cresson. We have a LOT of events scheduled for this season with local SCCA Time Trial (Max1 class), NASA TT (TT2), SCCA autocross (Cam-C) and Apex Lap Attack events. All of these classes allow aero, so soon after we get the baseline laps in we will tackle adding the wing and splitter, looking for more time.

                  Thanks for reading!
                  Terry Fair -
                  2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                  EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev