| Full report on the Grassroots Motorsports Magazine Ultimate Track Car Challenge with video :) 
I received the invitation to the Grassroots Motorsports magazine challenge about 1.5 months before the event. We were grouped into Shop Varsity class (Varsity = forced induction, Shop since we are a business, though I am not really a tuner shop), pretty much the highest class of the competition. The rules were pretty much unrestricted for this class, so I decided to build the car to these rules. We were previously running Modified class at the Redline Time Attacks, which required all factory dash/door panels and all factory glass, as well as DOT approved tires with threadwear rating of >50. For the GRM event, I gutted the doors, removed the door glass, and used Pirelli slicks. But I did keep the dash panels for cosmetic reasons. The car had a few other new mods, the most significant being the full cage and new coilovers (Zeal Super Function 2-way coilovers). This new setup and new tires completely altered how the car handles, but I did not really have much opportunity to test the car ahead of the event. I managed 1 day of testing at Motorsport Ranch about 2 weeks earlier, and I got the setup pretty good, but definitely not yet optimal. I did the best I could with the time and budget constraints and headed off to Virginia. When I arrived at VIR, I wasn't too confident at our chances, there were some pretty serious cars and drivers there, as well as some crazy ones :o A couple of Z guys near VIR showed up to support us: Insomniac, cherry, bobZtwin. The NoVA crew failed to show up as they threatened to, due to lame excuses such as having to work on a Friday :/ The event takes place all in 1 day, with 1 practice session and 3 time attack sessions. The best lap time in the 3 time attack session is what determines the placing. The cars are gridded based on the best lap time set in previous sessions. Our practice session was unfortunately cut short due to a CAS connector that worked loose, and we were not able to even complete a full lap under power. Since we did not really run the practice session, the tire pressures were not setup (they were over-inflated by 3-4 psi) and damper settings were not properly adjusted for the first time attack session. To make things worse, since cars were gridded according to times from practice, we were gridded LAST. Yet Ryan Hampton piloted the car to a best lap of 1:36.5, practically passing nearly the entire field of cars. This is the time sheet from the first session: [ http://www.splparts.com/events/grm0707/Time1.jpg ] To get an idea of how fast that is, I found the NASA lap records for VIR North: [ http://www.splparts.com/events/grm0707/NASALapRecords0507.jpg ] As we later found out, the car was only running 13-14psi of boost (the reason will be found later in this post). So despite over-inflated tires, low boost, somewhat un-tuned dampers, having a lot of traffic, zero practice, plus a relatively hot day not ideal for traction/power, we bettered the existing NASA lap records at this famous track. Here is the video (size: 70MB) from the session, sorry there is some audio clipping (no its not the engine cutting out) and dropped frames. [ http://www.splparts.com/events/grm0707/Time1low.mpg ] With the tire pressures and dampers adjusted, and with some practice under Ryan's belt, we were expecting to better the time from the first session. At this point we were 3rd overall (Noble was disqualified for going off track that session), so we were pretty hyped. Unfortunately the 2nd place car (Danny Popp's Corvette) had a loose dipstick (which blew smoke) and had to pit in after 2 laps. That prevented Ryan from going full blast until the 3rd and 4th laps (though the 3rd lap was compromised by a slow exit onto the front straight due to the Corvette pitting). In the end the 4th lap was the only clean lap we had that session because we caught up with the back of the pack by the 5th lap. Still we bettered our time to 1:35.9. Before the last session, I double checked the Motec datalogs and was surprised to see the car was only running about 13-14psi of boost. I adjusted the boost map to try to get the car to run 20-22psi that it usually runs, and again we thought we would be able to make up more time with probably another 100hp on the car. In the rush to get the car out for the last session, I forgot to latch the hood pins, which ended our day early: 
Ryan gamely went out with the cracked windshield for about 5 mins towards the end of the session but the cracks on the windshield reflected the evening sun at some critical corners, so Ryan was not able to set any good times. 
In the end, we were happy to finish 4th in class and 5th overall, especially given how compromised our runs were (practice, traffic, power, etc). Top 5 finishers at the Grassroots Motorsports Ultimate Track Car Challenge: Varsity Shop (10 entries)
1) 1:28.401 Tommy Archer Dodge Viper CompCoupe
2) 1:33.794 Chet Fillip Mosler MT900S
3) 1:35.973 Derek Whitis Noble M400
4) 1:35.990 Ryan Hampton Nissan 300ZX TT
5) 1:36.157 Robert Fuller Mitsubishi Evo 8 MR The cars that beat us were all serious factory built race cars: Tommy Archer in a ALMS GT2 class Viper Competition Coupe
[ http://i100.photobucket.com/albums/m23/InsomniacZ32/VIR%20Time%20Attack/Racing/DSC_0201.jpg ] 680hp Mosler MT900
[ http://www.cardomain.com/ride/2641877 ] 630whp race-prepped (Lexan windows, etc) Noble M400
[ http://www.cardomain.com/ride/2651790 ] Some of the other competition that we beat at this event: Buschur Racing Evo driven by Robert Fuller (aka. RobiSpec)
[ http://www.cardomain.com/ride/2618787 ] Racer-X NSX
[ http://www.cardomain.com/ride/2566363 ] BimmerWorld 320i turbo driven by James Clay (Speed World Challenge Touring)
[ http://www.cardomain.com/ride/2561560 ]
Video:
[ http://www.brightcove.com/title.jsp?title=1130049316 ] Chip Herr (Speed World Challenge Touring) Audi S4
[ http://www.chipherr.com/ ] I had nice pictures of the car build up ahead of these events but due to a hard drive crash I've lost all the pictures from before. I re-took some pictures this week but they are not as nice... Safety equipment -- new cage with externally accessible fire system and electrical cutoff switch: 
Dash w/ main fuse panel and driver accessible fire system handle: 
SPL carbon bucket seat (custom upholstered by CollegeBoy/Import Extreme in leather and novasuede, Schroth 6-pt harness, Stroud window net, SFI padding: 
SPL custom fiberglass t-tops, mainly for safety but also shaved 10 lbs off the roof: 
To improve reliability and make the engine assembly more compact, I re-did the plumbing with aluminum hardlines. Notice the dual wastegate control solenoids, Swain coated equal length manifolds and Swain coated turbine housings. 
Another pic of the plumbing from the back: 
From the other side: 
Hmmm... notice anthing? Found out why the car was only running ~14psi of boost: 
The Swain coating also did not reduce surface temps as much as I thought compared to the previous setup (loosely covered exhaust wrap). I had also changed from a straight coupler to a hump coupler, which reduced the clearances somewhat, though there was still about 1/2" of airgap (looks closer due to angle of the shots) from the manifolds to the coupler. Evidently that was not enough and I should have taken a precaution and added more thermal barrier material in between. Since I was running a MAP system with the Motec, the engine continued to run fine, but with just 13-14psi of boost, we were by no means close to the most powerful car at the competition. As it is, I am surprised by how well we did with this little power, but certainly this underlines how important it is to have a well setup (suspension and aero) car. I think suspension tuning is probably the most neglected aspect of tuning, even with the track enthusiasts on this board -- setting up a suspension is not a simple matter of slapping some shock/spring setup with a bunch of "performance" control arms with some "good" alignment settings, much as you would not expect to make good and safe power just by slapping a bunch of performance engine parts together and running a JWT chip. It may not be as glamorous as power, but suspension (as well as aero) tuning is worth more time on a track than raw power. Finally thanks to Twinturbo.net and 300degree for their sponsorship, without which we would probably not have been able to make this event financially.
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SPL @ Grassroots Motorsports Ultimate Track Car Challenge - 
