Vorshlag/AST EVO X - Project / Deveopment Thread

[Fair!]

Re: Vorshlag/AST begin Evo build!

Quick video from last Sunday's event:



Not hardly my best run, but its the only decent recording we managed this day. None of Amy's runs recorded correctly either. Several big driving mistakes on the run above, that I freely admit.

[hancheyb]

Re: Vorshlag/AST begin Evo build!

Kudos to Jason McCall! He Pax'd awesome.

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for August 17th, 2009: Amy and I spent most of Saturday at an SCCA practice event, testing new settings, alignment, tire pressures, and new parts.

Pennington Field's high grip concrete is a great test site, even if not that big. Brian came out for a few hours to help and we all drove the car in several iterations. We had some other known drivers there to compare to, namely Chris Ledbetter's STX prepped E36 and Andy Hollis' ST prepped Civic (Andy took an unusual number of runs, prepping not only for Nationals but also doing a test for an upcoming magazine article).

There was a timed ~23 second practice course that we could take 1-2 laps on at a time and we tested a lot of theories and setup changes, finding 1 full second from tuning by day's end. The skidpad was also helpful when coupled with our pyrometer tests, which showed us that the low camber (-2.5°) setup we had aligned to last week needed another degree of camber after all. The increased tire pressures helped considerably as well, going from the 29-30 psi range to 40-45 psi up front by days end. Big car, little tire, needs more pressure.

We had one more test to try but the event was shut down abruptly at 3 pm, so we left that setup and packed up the car/trailer/truck and headed back home until Sunday, when the competition event would be held at the same site.

Results: PAX - Final - Raw (overall)

Andy Hollis and the other fast ST Civics have made a habit of bumping up to STU at our Regionals as they have a good shot of beating the "Faster" STU cars on this smaller site's tighter layouts. On Sunday's event I started out with that last, untested change from Saturday, which proved to not be beneficial. My first run was 1 second slower than 2 of the faster STU drivers, so I quickly changed back to the last, proven setup. I made changes after almost every run yet again, but kept finding time. In the end my times were bested by 3 other STU drivers... Andy Hollis had me by .6 sec and Jason McCall in an '08 STI (that we've done a lot of work on) and Ken Orgeron's E46 M3 both had me by a little over .1 sec (they were .005 sec apart). As I was changing things between each run this made for more of a test event than a competition, and by my 4th run I felt like the car was handling pretty well, without looking at the car from outside or seeing data.


The front end looks higher because it is... we were testing another theory that didn't hold water. Its going back down by 1/2"

Amy ran in in the last Heat of the day (temps were hovering around 99°F by that time), running in the local PAXed Womens class and starting with the setup I finished with. Her first run started out quicker than mine did but while watching her on course I saw some things going on in the front end and changed the rebound yet again, and she kept improving her times throughout the heat. By her 4th and final run she had bested my time by .01 sec and won her class by 1 sec, so she was happy.


Then Amy skirted me by a fraction of a second...

We've come to realize that this 3700 pound car (with driver and fuel) is probably limited more by the 245mm section width than most other competitive STU cars, none of which are this heavy. The trick is to get the car to the limit of the tires' adhesion (a slight push in steady-state) and then keep it there, or it moves into a loud and ugly push. It doesn't feel fast around sweepers and at this overall weight it may never be. The SST transmission did work flawlessly in S-Sport auto mode at this site for both days, so the odd shifting issues we saw at Vail had to be altitude related, we think.


The unusual Figure 8 course layout made for lots of loooong sweepers.

In the end we PAXed well enough (15th and 16th out of 126) but its not where we like to be right before Nationals. The grip was good (1.2g lateral and 1.13 under braking) so basics are there. As you can see above the course layout was laid out with a LARGE emphasis on long sweeping turns, having a huge figure 8 dominating the course design. There wasn't much room to accelerate as it looks, either, as there was a transition at the start of one of the long stretches in the "X" and a transition at the end of the other. This emphasis on sweeps does not exactly play to the 3500 pound EVO's strengths, which are: braking, acceleration, large speed changes (where we'd see lots of up/down shifting) and transitions. Not to take anything away from their driving, but the cars that outpaced us in STU were a good bit lighter (Civic is ~1960, STi is ~3150) and/or had much wider tires (E46 M3). Excuses - I've got a million of em!


Hollis was on fire and PAXed 4th


Ken O was fast in his STU prepped E46 M3 on D-Force 18x10s & 275mm tires


Paul and Jason are getting quick in the 08 STi on ASTs


Todd M's Civic was one of the ones that didn't beat us...

Anyway, we don't think these Pennington courses are indicative of what we'll see at Nationals, from what we've heard from the course previews by Howard Duncan. Our setup has changed drastically from the Vail Tour 2 weeks ago and hopefully the Lincoln site will play to this car's strengths... and hopefully Amy and I can drive well enough to show the car's performance. We'll be taking lots of laps at the Nationals Practice Course looking for the right setup.

Until next time...

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for August 7th, 2009: Short update to the above post - now with video.

In-car video from the Vail Valley Tour. This is my 3rd run from Day 2, and the time was almost exactly what John ran in the same car. Warning - it does not sound good, as the front tires are really howling:


click for video

Stuart is out test driving the Evo on one of our secret test locations, but so far Brian and I both feel like its now about 100% better. SCCA practice next weekend and TAMSCC practice the week after will shows us what we need to see.

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for August 6th, 2009: Amy and I went to the Vail Valley National Tour with the EVO last weekend. We got back on Tuesday but have been playing catch up all week, so I'm just now adding our event report.

Vail Valley National Tour update - the battle of scrub

It was a tow from hell getting there... 16 hours straight thru, after working a full day. Towing over several mountains including an 11,000 foot high pass wasn't fun in our truck, either. We got there Friday morning at 7:30 am, and Amy was entered in the EVO school at 8:30 am. So we grabbed an hour of sleep, our only rest for 2 days, and spent the next 3 days testing and racing.



Weather couldn't have been better - it sure beat the 100°F heat we had in Texas! Beautiful mountain views surrounded the Eagle Airport site as well. We had been battling some serious understeer the past several weeks, which I will touch on in a bit. Amy got a lot of test runs during the Evo school, but I think she could be teaching at these things by now (she has instructed at several driving schools in the past and has more wins at Nats than many of her former Evo teachers), but she says "it never hurts to get an outside perspective" and she got a good number of laps in before a freak downpour at 11 am. It dried quickly and (co-driver) John Scheier and I started taking laps at around 2 pm. The car was pushing as badly as ever, so we quickly headed for the pits and made some big changes between the many test n tune runs we made for the next several hours.

We swapped rear swaybars (from a Cobb hollow to a Works solid), adjusted all of the shocks, changed the front camber by a full degree, tweaked the front toe, and made laps in between changes. Nothing helped. We could get the turn-in right but as soon as the front wheels turned more than a few degrees the front end would wash out. The tires were howling, and we had no front end grip. Front tires were SO hot, rears were dead cold. Frustrating! Slaloms felt OK but the many 180 degree turn-arounds we had to drive through all weekend on the narrow airstrip courses were murder. Losing so much time in the big turns!



We've been playing with all sorts of adjustments on the car of late to try to re-discover some seriously missing front end grip. Ever since we switched from the 265mm AD07s we've been fighting a serious push, but the lack of performance wasn't as apparent at higher speed events (time trials/HPDE) nor at local autocrosses, where we still seemed to be doing well overall (but slowly slipping back in PAX). Too many spring rate changes to count, ending up with 700# fronts and 1000# rears, which seem a bit extreme because they are. On top of this push, the formerly flawless SST S-Sport automatic shifting mode was acting funny at this event for the first time ever, probably due to the 7000 foot elevation of the site? It needed coaxing to hold a gear and not upshift at odd times. Never done this to us before, so this was a mystery. We went to full manual shifting on some runs.


285 Yokohamas and 18x10s on an E36 M3!? Mayfield was FAST

At this Tour event we had a lot more competition (19 cars in STU!) and it was fairly obvious that the car was off the pace with all 3 of it's drivers. It wasn't until we got back that one of the obvious deficiencies was found - tire pressure. Look at this picture:



That outside front tire looks like it is about to come off the rim. We were running the sub 30 psi pressures that had worked so well on the wider 265mm AD07s. We'd noticed odd tire wear on the 245s lately though - it as wearing the insides more then the outsides up front. WTF? There was something else going on that was masking the lack of tire pressure that is so obvious from these pictures. We're running 40 psi up front on future testing, starting today. 3700 pounds with fuel and driver is too much for 29 psi. It may have worked on the 265s, but not on these 245s. We also noticed a lack of dynamic camber in higher angle turns, not readily apparent until you study multi-sequence pictures from the same turn. It needed more caster.

Anyway, we fought the car all weekend, barely maintaining our mid-pack finishes in this field of STU heavy hitters (driving our butts off to get 10th an 13th places in Open). Amy still won STU-L somehow, but she was struggling more than normal to stay in front. She had a "mystery cone" assigned to her fastest Saturday run that knocked a cool second off her next best time (I watched that run from start to finish - it was bogus) which made it too close for comfort. We tried all manner of changes all weekend, even adding as much as 1/2" of toe out in the rear to try to get this thing to rotate. Nothing made a difference, which just didn't make sense. Something else was fundamentally wrong. We finished our runs, taking our licks, then packed it up for an 18 hour tow back to Dallas (record traffic jam at the Eisenhower tunnel made for an extra 2 hours getting from Vail to Denver - yay!)

On our way home we were scratching our heads, looking for answers. The video and data showed what we already knew - there was no front end grip. We had plenty of static camber and tested there with the the extremes. Hanchey called another engineer/racer friend of ours (Matteucci) and they keyed in on the many changes we've made to the car this year. We went from 4200s to 5200s (to test both AST strut designs), changed spring rates many times, played with various camber and toe settings, multiple swaybars, and more importantly used 3 different sets of wheels and 4 sets of tires in 2 widths. We also went back and forth from track to autocross setups, sometimes week after week. The problems seemed to follow the 245mm tires, and more specifically the 18x10" Enkei front wheels we've settled on lately.


Kazera 18x9.5" wheels are 3 pounds heavier, but reduce front track width by a full 2", reducing scrub!

Remember from earlier posts in this thread that the Enkei RPF1's we have on the front (6.7" backspace) had even less offset than the 18x10.5" NT03's we've been running for track events, and these RPF1s also needed 15mm of spacer to clear the calipers. The black CCWs on the back had more backspace as well (7") but couldn't clear the 14" front brakes with any amount of spacer. Well this weird offset issue with the front wheels was causing a terrible scrub condition, moving the centerline of the tire further away from the Kingpin angle defined scrub radius. I rechecked the toe at the event and noticed the front track width was alarming wide... nearly 74 inches! By contrast our old STU car, an E36 M3 with 18x10" wheels, has only a 67" front track width. Even our V8 powered E36 race car with 315mm tires has only a 72" track width! WTF?

There are ways to improve weird kingpin angle/scrub issues, namely adding more positive caster. We already had a much improved over stock +5.6° of caster, but our three previous BMW racecars have always been able to achieve +7 to +9 degrees of caster, with the steering feel and dynamic camber that were much better than what you typically see on the AWD cars. They come with much more caster to start with, and we improve on that with our plates. So the first thing I did when we got back from Vail was to make a new High Caster version of our camber-caster plates. We had also just made a short production run of new HC1 plates for the GD Subaru and EVO 5-9, some of which are already on testers' cars. This EVO X version made this week was hand built and adds .400" of more caster offset, which should add another degree and a half of caster, getting us closer to +7° (we will verify with a laser alignment soon).



We also dumped the RPF1s and CCW wheels this week, as they just are not the right fit for this car at all (CCWs are sold, the two RPF1s are for sale). The 10.5" wide NT03s are too wide for the little 245s we're restricted to for STU class, so we went looking for an 18x9.5" ET30 offset wheel... and found them from one of our employees! Stuart here at Vorshlag had a (discontinued) set of Kazera 18x9.5" ET30 wheels from an S197 chassis Mustang and they fit the Evo nearly perfectly. We're using a 5mm spacer in front (to clear the tender spring we need to run for use with a test sensor - a shock pot) and no spacer in back. The width change alone knocks out a full inch of track width plus losing a total of 20mm of spacer width is another inch less track/scrub... so track width in front is a full 2" narrower now. This is a HUGE change, and a GOOD thing when you are trying to slalom around cones. Every inch removed from track width can make significant time improvements in autocrossing.



These wheels aren't the lightest thing we've ever run (21 pounds) but they clear the brakes better than anything other than the NT03s, and due to the proper backspacing they fix much of our scrub problems. The added caster from the new plates was obvious on our first test drive, with improved steering feel and the most important improvement - the car rotates now! I could saw the wheel and break the rear tires loose at speed, which is so much better than before. No more howling front tires, as the scrub problems in front seem to be fixed with the new wheels, and the increased tire pressures feel better as well.

So now we're sort of back to the drawing board on the rest of our Autocross setup... we've started by resetting the adjustable swaybars on both ends, changed camber again (from -4 to -3°), and have to settle in on the spring rates now that we have the other fundamental issues improved (but it feels pretty damn good with 700/1000 - corners flat!). This scrub issue has probably been holding back performance for a couple of months. Good grief - we've only got a few weeks until Nationals, too. Today Brian also swapped back to the RacingBrake pads after he opened up the struts and put them back on with the new plates. This moved the car away from the ultra-hard race compound HTC-70 Hawk pads in front, as they take too much time to get up to working temperature. Great for the track but not so good on your first autocross run (we can't just "drag he brakes coming to the start line" due to the SST trans, either).

We've already scheduled two more test events in the next 3 weeks, so we've got some work ahead of us. If we can regain some of the performance we had earlier this year we think the STU competitiveness will return. To top off the week we have also had to pull the trans from our V8 powered BMW, as the input shaft decided to leave the bellhousing at 155 mph at TWS last weekend. Brian was racing it at a NASA Time Trial... good times.

Tune in for more test results soon...

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for July 28th, 2009: Here's a few updates from the last week with the EVO X.



Pictures from last weekend's Texas Time Trials event: http://vorshlag.smugmug.com/gallery/9060410_Fotkg


those 3-piece CCWs on our V8 BMW are anchors

In-car video from this Time Trial event (in the 490 whp BMW):


This event on Saturday was a blast. We'll edit the video from the EVO and post it up next. As crazy as the V8 car looks in the video above the EVO was only 3 seconds a lap slower, on street tires. It was SO much easier to drive than the BMW on 4-year old R compounds. TTT president David and co-driver Gerry set-up two courses... one was a road course with timers and the other an autocross. We played with the setup on the EVO off and on all day (as well as several other cars), and worked the new engine in the BMW for many laps. Trying to de-bug little things on this car before Brian runs it at Texas World Speedway (NASA TT) next weekend, while Amy and I take the EVO up to Vail for the National Tour (a 15 hour tow, yuck). If you are in the Dallas/Ft. Worth area and have done some autocrossing or HPDE events before, check the Texas Time Trials schedule and come join them for an event. $40 for as many runs as you can stand in the 4-5 hours of your run group, no corner working, free hot lunch, and tons of fun!

Since one full day in 108°F Texas heat wasn't enough, Amy and I ran the EVO at an Equipe Rapide autocross on Sunday.


It was hot so we spent the 4 hours in grid under our pop-up tent!

Pictures from ER's Challenge Cup #5 Autocross: http://vorshlag.smugmug.com/gallery/9060415_zWVVV

The new 1000#/in rear springs (we had 800's, switched to 900's early last week, then to 1000's later in the week) really helped the car rotate better and kept the car flatter in corners. Still playing with shock and bar settings with these new spring rates, but the car rides surprisingly smooth on the street with these crazy rates.

Results: http://www.autocross.com/er/equipera...ndex.php?id=64


Left: tight slalom # 3. Right: Tight turn-around # 2

I had STU covered until Andy Hollis showed up. ST Hondas are so damned light, and all 3 of the competitive Texas area Civics jumped classes to run in STU. The tight and tiny 33 second course had no place that the AWD turbo cars could use their advantages, so Andy's sub-1900 pound Civic put .3 sec on me in the big EVO, pushing me to 2nd place on the 4th run (I still had him in 3, heh!). Amy was another .5 behind in 4th, with another Civic in between her and me (she was also edged out on the 4th run). At least she won their Women's "RapidPax" shootout, and $40 cash money. At ER events if you pay $10 extra you get 2 extra runs which are judged in their "RapidPax" results, with cash payouts. I choked in the RP runs and went slower, bah.

The course was tiny - literally 2 big 180° turns, 3 tight slaloms, and two 90° turns. The start was severely "kinked" and there was nowhere to use any of the EVO's power. I hate those types of courses... its all about grip, grip, grip. They had over 40 Formula SAE competitors at the event so they kept the course small to work better with their itty bitty cars and time constraints. Anyway, this sized course is typical of events at this small concrete site (Pennington Field), but I still always b!tch about it.

3 of my 4 timed runs were in the same tenth, but I just watched the runs on video and there were still some mistakes, so I'm sure I left some time out there. It was so different with 200# more rear rate that we had to re-learn driving slaloms again.



Brian has been playing with a new Race Technologies "Dash 3" unit and a CAN-BUS cable, getting the Mitsubishi ECM to talk to the DL1 data logger. There's pages of real time data shown on the DASH3 display reading right from the OBDII data stream... tachometer signal, TPS, and lots more. Pretty cool little unit. This will let us datalog lots more stuff and put it on the video overlays.

OK, we'll update again after the SCCA National Tour in Vail next weekend!

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for July 14th, 2009: A belated update on wheel studs, spacers and lug nuts.

The EVO X MR uses lug-centric wheels from the factory, meaning, the wheel doesn't fit snugly to a hub, but is rather located by a long shank on a square shoulder lug nut. Its not ideal, but that's the way the factory chose to do it. The factory lug nuts therefore don't fit most aftermarket wheels, which tend to be built to utilize a tapered seat lug nut. So whenever we switch from the stock wheels to the Enkeis or CCWs we have to swap lug nuts. Not a problem for us, as we have thousands of tapered seat, M12-1.5 thread pitch, open ended lug nuts in stock.


Stock length rear studs (left) vs long wheel studs (right) on the front of our EVO X

Since the Enkei NT03+M 18x10.5" wheels didn't need a spacer so we used the stock wheel studs and our tapered seat lug nuts. Going to the 18x10 RPF1 Enkeis we needed to use a 15mm spacer in front, to clear the calipers. This entailed the use of longer wheel studs, so we used the 3" long ARP press-in studs. There's a detailed instruction guide here.



These have worked great for both sets of Enkeis and the CCWs. About a week ago I had the stock ADVAN tires remounted on the stock MR wheels. We have race or street touring tires mounted on all the other sets, so it was time to put the stock wheels back into use. I go to plop the wheels on and went to grab the factory shank style lug nuts and ... oops... then are a closed in lug nut. This won't work with 3" long wheel studs. What to do?!

I looked for another 10 replacement lug-centric style M12-1.5 lug nuts and I was going to cut the tops off, making them "open ended". A quick check of auto parts and tires stores reveals that Mitsu uses a proprietary shank length, so its dealership time. Bah, I'll just cut the stock nuts for now.



Chucked each lug nut in the lathe and cut the tops off. This doesn't weaken the lug nut, as its simply a cosmetic cover. Now the stock lugs work on the stock wheels with the longer studs. Cool.

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for June 15th, 2009: Our wheel fitment dilemma is solved, for the moment. We are using two different wheels for now...

Here's the weights on the stock wheel & ADVAN tire package, the CCW 18x10 with 245 AD08 ADVANS and the latest 18x10 Enkei RPF1 wheel and 245 mm AD08 setup we're using on the front:


Factory EVO MR 18x8.5" wheel and 245mm Advan tire, 46.8 pounds


CCW 3-piece 18x10" wheel and Yokohama ADVAN AD08 tire in 245/40/18 is 47.5 pounds


Enkei RPF1 18x10 with ET38 offset wheel (wheel was 19.1 lbs) and 245 mm AD08 = 46.3 lbs

So our latest 18x10" setup is lighter than the stock, skinny wheels by half a pound. Not too shabby.


Front caliper clearance is the trick here. With 15mm of spacer up front the wheel would finally clear.

We had already test fit these particular Enkeis in the past and they fit beautifully in the rear, but we could only find two of these wheels in the country. So we got two of them last week, found the spacer combination needed to clear the front caliper (15mm), and ran them up front with the CCW 18x10 on back. Once we can source 2 more of the Enkeis we'll put them on the rear and sell the CCWs.


The rear fits easily with the 6.7" backspace 18x10" CCW. It has 20mm clearance to the control arm and rear shock's spring perch

This unusual wheel setup finally allowed us to run the new Yokohama 245/40/18 AD08s at an autocross this past weekend. I have to say - these tires are awesome.

I'd figure I'd update on the EVO's track wheel & tire setup in detail. This is what Brian is running at NASA TT events, HPDEs, and for the time being, as the street tire setup.


Wheel is 21.4 lbs. Wheel + 265/35/18 Yokohama ADVAN AD07 is 48.5 lbs. The intricate spokes are hard to keep clean.


This Enkei is an NT03+M, 18x10.5" wide, ET30 and super strong


This package fits the front and rear of an EVO X with no spacer and only light fender rolling in rear. 285mm tires might require a bit more rolling out back


Shot from underneath the front with the track wheels & tires mounted

These AD07 tires are wearing extremely well and keep knocking down incredible lap times, race after race. They've also been good street tires and have done autocross duty for the past few months, while we awaited the new AD08 to arrive. I consider the older AD07 to still be a competitive tire for Street Touring and TT events.

We're mounting a set of 265mm Yokohama A048 R compounds on this set of wheels for use at the 10th Anniversary Celebration event at Motorsports Ranch this weekend. If you are a member at MSR and are coming to this event this Saturday, June 20th, look for the Vorshlag crew and our EVO at the Yokohama booth. We'll be giving ride-alongs all day on the 1.3 mile road course, to show people the grip of the A048. A supercharged Audi R8 will also be there for Yokohama to give ride-alongs on AD08s. If you are not a member at MSR... well, find someone who is and join them for this event.

[hancheyb]

Re: Vorshlag/AST begin Evo build!

Pics from the race:


The only EVO X we saw at the race was still running at the end

Evo was a SST too!

[GotCone?]

Re: Vorshlag/AST begin Evo build!

nice spacers..

sure you guys had a blast over there.

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for May 28th, 2009: Brian and I just got back from the Nurburgring 24 hour race and a trip to AST in Holland.

We were happy to see that our prototype wheel spacers were done when we got back.



If everything works out the way we want, we'll have the CCW 18x10s and AD08s on the car tomorrow!

Pics from the race:


Scirocco R chased by an Audi R8


The only EVO X we saw at the race was still running at the end

[Fair!]

Re: Vorshlag/AST begin Evo build!

Project Update for May 21st, 2009: Still waiting on spacers for the CCWs from one of our dealers... about to design some here and just have them machined. Here's some wheel & tire weights:


Factory EVO MR 18x8.5" wheel and 245mm Advan tire, 46.8 pounds


CCW 3-piece 18x10" wheel and Yokohama ADVAN AD08 tire in 245/40/18 is 47.5 pounds

That's kinda funny... the "lightweight" MR wheel is barely any lighter than the 18x10. CCWs aren't known for being light, either.


Did a quick rendering.... in goooooooooooooooooooooooooooooold!

Spacers for the EVO are designed and prototypes are being machined. We should have some ready by the time Brian and I get back from Holland next week.

[GotCone?]

Re: Vorshlag/AST begin Evo build!

DoH!

[Fair!]

Re: Vorshlag/AST begin Evo build!


YouTube video from HHR inside a MazdaSpeed3

Check the video above. At 3:30 this MazdaSpeed3 lets a white EVO X go by, then at 4:00 the EVO goes veering off into the grass. That's the one in the picture below. Good stuff.


A little dirt trackin' never hurt a rally car...

[cledbetter]

Re: Vorshlag/AST begin Evo build!

Man the car looks awesome!