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Unread 08-31-2016, 05:00 PM
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Fair! Fair! is offline
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Default Re: Vorshlag BRZ/FRS Project Development Thread

continued from above



We have been keeping an eye on the used prices of these cars and recently she found some listings on Craigslist offered by a body shop / car dealer in our area that specializes in 86 cars. He usually buys them with some "history", fixes them up, and sells them at lower than normal prices. All on the up and up, no false records, and we knew this car had some light front end damage that was repaired with OEM parts. We checked out this car closely, test drove it, negotiated a great price and then bought it.



We had previously weighed Matt's BRZ at 2775 pounds (Limited model with some options) but this FR-S was a good bit lighter at 2634 pounds. This was with the trunk junk removed (see below), low fuel, but otherwise bone stock. Even had the heavy stock 17x7" wheels still on. The low fuel level and removal of the trunk junk skewed the front bias to nearly 57%. Not what you'd expect in a front engine/RWD chassis, but I would reserve judgement on how this affects that car once I drove it on track. If it had massive understeer, I knew what to blame...



We pull all of the spare tire, jack and other junk from the trunk to get our initial baseline weights because that's how we race these cars. We even ran it fairly low on fuel at our first road course test (see below). The low weight is what is so amazing about these cars... this weight is an astonishing 810 pounds lighter than the 2016 Focus RS we have been doing track testing and suspension development with lately (see development thread here).



This car was no cream puff, but we knew that going in, and it was reflected in the price. The front tires were corded, one ball joint was shot, and the brake pads were kaput. The video below shows how to test the ball joints on a car, and the left front was badly worn on this car. No worries.


Short video showing the worn ball joint + new control arm

The ball joint was not easily sourced from our normal wholesale parts suppliers (other than some aftermarket, racing style ball joints), and neither was the entire front control arm (other than some sketchy looking units on eBay). Many of the wholesale parts site listings for the 86 chassis said "under development" for the control arm and ball joints. WTH?



We were pressed for time so we ordered a new control arm (see above left) for the car from our local Subaru dealer, which had it to us the next day. $247 retail, ouch. I talk about the design issues we can see in the front control arms in the video above, but yea - I'm not a fan of the "axially opposed" bushing layout nor the thin, single layer, stamped steel control arm. Very easy to flex this arm, and that becomes important when you really add a lot of mechanical grip (see "Plans" below). Oh well, it was replaced and the front toe reset.



Since the tires were damaged from the bad ball joints, and we wanted to get a "stock baseline lap" in at our local road course, I went ahead and purchased some cheap OEM replacement tires for the car. I was looking for something in the factory 215/45/17 size with close to the 240 treadwear of the craptastic Michelin Primacy tires they come with. Not because I like those tires, but just to see similar grip for the baseline test lap. I found some "Firestone Firehawk Wide Oval Indy 500 XL" all-seasons on sale for $50/each from TireRack. These were the right size and 320 treadwear. Close enough!



As much as it pained me to buy what I consider to be "plebeian parts" to replace out the worn OEM bits, it was all for the baseline track test. So we picked up some cheap O'Reilys house brand, quiet "ceramic" style brake pads for the front and rear. $45/axle set, and we didn't even turn the rotors. We might be replacing all of this with aftermarket bits soon, so I wanted to keep costs low and just get it "as close to stock" as quickly as possible.



The engine is bone stock on this car and with 71,000 miles it seems to run as good as any other. We might test some new parts from a few suppliers we have worked with in the past under the hood - things that weren't yet developed in late 2013, when we had Matt's car available to use as a test vehicle.



There is some weird fake diffuser panel on the rear, which looks factory, supposedly part some option package I'm not familiar with. The exhaust looks pretty stock as well.



Pulling the front undertray off reminded me how convoluted and "non-flat" these front panels were. Maybe there's a need for a flat undertray? That's a zero point mod in NASA TT classes. Oh and that exhaust manifold and catalyst setup? Gah, what a mess. Haven't really kept up with the 86 scene to see what long tube headers are worthwhile, but we might have to try something to give this 200 hp 2.0L boxer a bit more "pep".



My shop manager Brad did a full track inspection and flushed the brake system on the FR-S with Motul RBF600 fluid. Why? Well I won't skimp on the brake fluid, even for a "baseline stock track test" like this. This is the FIRST upgrade we tell people as an HPDE instructor that is a MUST DO - the fluid. Craptasitc parts store DOT3 fluid boils at much lower temperatures, and when that happens your pedal pressure drops and you often go flying off track. Brake fluid pressure loss is never EVER fun, and we do this to even bone stock cars before they go to track events.


Setting the warm tires to 34 front & 30 psi rear, which made for decent wear patterns on the shoulders

The FR-S was now ready to take to Motorsport Ranch and run on one of their member days, which we did last Saturday. Normally we would load up the car into our enclosed trailer and go to the track but I had a customer's Corvette loaded for an autocross on Sunday. Two hot August days racing in a row was going to take its toll on me!

FR-S BASELINE TRACK TEST - MSR-C, AUGUST 27, 2016

In less than a week since buying the FR-S we had it repaired, filled with proper brake fluid, and ready for track use. We replaced the worn parts with as close to OEM spec as possible, to get a fair baseline lap time that represented these cars in stock form. We never got to do this in Matt's BRZ - because it wasn't my car, and he wasn't crazy about tracking his brand new BRZ. This cheaper, 4 year old FR-S was bought to be driven hard!



Photo and Video gallery: https://vorshlag.smugmug.com/Racing-...n-Test-082716/

We got out to the track at 7:40 am with the first cars going out at 8:00 am sharp, due to a fog delay. The pictures from the first session are pretty foggy.



In the first session I did what I *assumed* was the correct sequence to disable both the traction and stability control systems. Pressed the two separate buttons. Of course that didn't work and above about 30 mph the stability control system still kicked in. Amazingly the car would rotate fairly well but if the rear saw any "yaw" the dash would light up and it felt like the rear brakes were engaging. GRR.



Chase came out with his co-driver Mark and he showed me the crazy Konami Cheat Code sequence needed to disable the electronic nannies. Never seen such a crazy thing: E-brake up and down 3 times, brake pedal up and down 3 times, then E-brake twice more, than brake pedal twice - all within 30 seconds of starting the engine, with the coolant up to temp. Sure enough, the light came on and it never engaged once in the next session.



So instead of going through this crazy pedal sequence each time we want to drive this car hard, might be a good idea to invest in this "magic box" that disables these two systems with a button press (or even defaults them off).


In-Car Video
of the FR-S in session 3, best lap

I drove Scottish Joe's 2015 VW Mark7 GTI (below) in session 2, then went back out in the FR-S with the "pedal dance" sequence and took another second off my best lap time in session 3 (shown above). There was a LOT of traffic to deal with in every session, and even my best lap had a pass, but I still managed to run three laps within the same tenth of a second (best of 1:31.90) in this session. I guess that's as good as I can do, and we will call this our "Baseline Lap Time" for a stock FR-S there.



Some reference times for MSRC 1.7 CCW: My quickest lap time in a street legal car here is a 1:17.25, which I set as the class track record in 2014 (still holding) in our NASA TT3 classed 2011 Mustang GT. More recent NASA lap times from March 2016 in my TTC classed 1992 Corvette (nearly bone stock in every way) were a 1:21.9 and a 1:27.6 the same day in our TTD classed BMW E46 330 (with cord showing on the tires). Those times were all on DOT-legal Hoosier R-compounds (A6 for the Mustang, R7 for the other two). In mid July of this year I tested a stock 2016 Focus RS to the best of a 1:27.40 on the stock 235mm Michelin PSS tires. This same day in August I ran the 2015 VW GTI to a best of 1:28.10 (don't have the video up yet).



So yea, the FR-S is relatively slow compared to these other cars, but these skinny 215mm tires are CRAP; these other cars had between 90-250 more hp than the FR-S does (except the BMW 330, which made 195 whp). We have several upgrades planned that I will discuss below, and we will try to get a new lap time after each stage to quantify any gains or losses.



Considering how cheap the tires were, I was strangely impressed with how neutral the car handled in stock form. Just a hint of understeer at the limit. And look at the lateral G traces that were logged on the AiM SOLO - they hovered at or even exceeded 1.0g in most corners. That's on 340 treadwear all seasons I paid fifty bucks a piece for! This is the first time I've tracked an 86 that was bone stock - the last time I ran some laps at ECR in Matt's BRZ (Nov 2012, shown above) it already had 17x9" wheels, 245mm MPSS tires, Vorshlag camber plates and Swift lowering springs. It was showing closer to 1.3g lateral on those tires, which is nuts for street meat.

The coolant temp gauge also stayed rock solid all day, even as ambient temps rose to near 90F, the needle never even got to the middle of the range. The stock brakes and O'Reily pads worked admirably, logging in the .9 to 1.0g range for braking each time, even if the fronts were billowing smoke in the pits after my stints. I never had a long pedal or any hint of fade. And I was Left Foot Braking and late braking the crap out of this poor car.

So for once I'm not going to dog on the car maker for making a crap suspension setup right out of the box. Could it have less dive and roll, more camber, grip and brake bite on a road course? Of course. We will address those things in time and share what we learn here.

PLANS AND FUTURE TESTING

We have a number of new 86 parts from some of our vendors that we would like to test on our own car before we add them to our website. Of course we will upgrade the suspension, likely with MCS or Bilstein coilovers and proper spring rates. We might develop a better OEM spring style camber plate solution before we go right to coilovers. We have made some OEM spring perch camber plate solutions lately that work with even the craziest factory top mount designs - like the S550 Mustang (below left) or the F22/F30 BMWs (below right).



Wheels and tires will be upgraded beyond the stock 17x7" and 215mm rubbish, of course. Deciding if we just hit the "easy button" and use the 17x9" Enkeis again or if we make a custom Forgestar 17" or 18" sized wheel instead. Once we get proper negative camber in the front of the car we can measure for wider wheels and tires. We will likely go with a BFG Rival-S or Bridgestone RE71R tire in the 255-275mm variety.



We might build up and run this car for a while in NASA Time Trial TTD or TTC classes, so we will work up some TT build sheets for both classes. I'm about to sell my TTC classed Corvette (above left) and Amy already has a TTD classed BMW 330 (above right), so maybe TTC makes more sense.



After that initial phase of product testing, well, we have some more serious plans in mind for this little FR-S. I will comment more about that at another time. Until then, thanks for reading.

Cheers,

Last edited by Fair!; 06-21-2017 at 10:38 AM.
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