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piknockout's STU Auto-x Build Sponsored by Agile Auto: 8/23 Update - WDCR #7

34K views 219 replies 29 participants last post by  piknockout 
#1 · (Edited)
Sponsored by Agile Auto in Fallston, MD

For those that don't know me, my name is Josh and I'm planning on using this thread to document my STU autocross build as well as my progress throughout the season including setups and changes. To start things off, I would like to give a BIG THANKS to Hill McCarty at Agile Auto for his support and help in this build, along with all the help in the past!
Now for a little background. I've been autocrossing now going on 5 years, with all of my previous experience coming from building my 2003 Nissan Sentra SE-R Spec V that I built for STX. Although the car wasn't the prime choice for the class, I was able to win STX for Philly Region in 2006, WDCR Region in 2007/2008, and Autocrosser's Inc. in 2007/2008.
After driving the car for 5 years, I knew it was time to get into a car better suited for it's class. I sold the car in August 2008 and spent the next few months doing some co-drives to figure out what best fit my wants/needs. A special thanks to John W. (ButtDyno) for letting me co-drive the WRX to finish out the WDCR STX season! But after driving Iman's (bdi) STU prepped STi, I knew exactly what car I wanted to buy and what class I wanted to run in. I've enjoyed the ST* class and knew that it was the right fit for me.

Through research gained here and conversations with several great STU drivers (Thanks Colin, James, Iman, JR, John W, and anyone else I left out!) I decided that a 2006 STi was going to be tool of choice. I searched through the classifieds on here, IWSTI, autotrader.com, etc. for about a month before I found what seemed to be the right car. It was a 2006 Aspen White STi with only 17,300 miles, a 3.5" APS exhaust, COBB short ram intake, and Accessport with Stage 2 tune. And to make it even better, the guy only lived 25 minutes away. A couple of weeks of pricing negotiations and the car was mine on November 21st!

The car shortly after purchase



The old autocross ride



Needless to say, the next 4 months were hell. Having this beauty sitting in the garage, doing research, dealing with snow and cold...just painful. Fortunately all that ended last Sunday when I began the autocross modification process.




Through yesterday I had installed the following modifications (it's been a busy week!):

- APS 3.5" turbo back exhaust with MIL.SPEC 100 cell race cat welded into downpipe by Agile Auto







- Hawk HP+ brake pads




- Braille 6lbs race battery



- Re-installed stock intake to replace COBB short ram to reduce intake air temp during summer events



- Corbeau 3 pt. Harness (autocross use only)




- Rolled front part of rear fenders



- Whiteline 24mm adjustable front sway bar with Whiteline spherical endlinks




Midway through the work



- Whiteline 22mm adjustable rear sway bar with Whiteline spherical endlinks




- Racecomp Engineering Tarmac 2 coilovers with 600lbs front springs and 500lbs rear springs topped with Vorshlag camber plates set at Racecomp suggested Track settings (Thanks Myles for the discussion and help!)





After the installs (before alignment and fixing front ride height...at 2am)



Test fitting some borrowed 17x9 et35 RE30's (before alignment and fixing front ride height at 1:30am)



- Ported stock headers by Agile Auto (no pics...forgot the camera)

- STU Protune by Hill at Agile Auto...318whp/318wtq (I know, kind of high...dyno chart to follow) along with a street tune 325whp/350wtq





And a few other things

- Alignment set at -3.2 front camber and -1.9 rear camber with zero toe for both
- Ordered 5Zigen FN01RC's 17x9 et43 in flat black
- Deciding between 245/40/17 Bridestone RE-11's or Kumho XS's
Where the car currently sits as of 3/14/09




First test day is this coming weekend on March 22nd with the Philly Region, followed by the WDCR practice event on March 29th. I'll either be running the borrowed RE30's with Dunlops, or if I make a tire decision tomorrow I should have that setup by the weekend. We'll see what happens. I don't know how everything will work first time out, but it should be interesting. Iman (bdi) will be co-driving with me this coming weekend to help work on the setup a little bit.

My plans for the season are to run a full WDCR schedule, Fed Ex Field events with Autocrosser's Inc, Citzen's Bank Park events with the Philly Region, the DC Pro (and hopefully Toledo, but doubtful), either the Seneca Tour or NE Divisional, and Nationals in Lincoln, NE.
 

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#5 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

looks good looks good. I'm also planning to do autox and track this season. I'll probably shoot you some questions later...goodluck this season
 
#7 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

car looks sick. Very impressive numbers and mods. Good luck this season. I cant wait to see how you like the car.
 
#8 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Thanks! The power mods are Protune, APS 3.5" turboback exhaust with MIL.SPEC race cat welded in, and ported stock header. The 3.5" exhaust is what I'm told is the major cause of the power gains. The high flow setup is generating a little bit of overboost which we're using to our advantage. I believe it tops out around 16psi. Not sure how that compares though, still learning this crazy STi stuff. :D
 
#10 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Good...I already got questioned on it once, I'm going on what Hill told me about what was happening with the 3.5" setup because I knew most only get around 300whp. I'll take what I can get though. :D
 
#12 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Josh, for what its worth. Im sure you know how much Torque helps in Autoxing. Im pretty sure a slightly more restrictive exhaust will yield significantly more Torque and only slightly less HP. And the torque is what really helps in when zipping around a tight course in a turbo charged car. I got 365 wtq with a el header, tbe, fuel pump, and spark plugs, tuned at 18 psi. But I sometimes over boost to about 23ish in the colder months. My whp was only 306 but Im not complaining, cuz it feels great!
 
#13 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Josh, for what its worth. Im sure you know how much Torque helps in Autoxing. Im pretty sure a slightly more restrictive exhaust will yield significantly more Torque and only slightly less HP. And the torque is what really helps in when zipping around a tight course in a turbo charged car. I got 365 wtq with a el header, tbe, fuel pump, and spark plugs, tuned at 18 psi. But I sometimes over boost to about 23ish in the colder months. My whp was only 306 but Im not complaining, cuz it feels great!

If you are implying he pick up headers for the car, it won't be STU legal and that is what it looks like he is trying to stay legal in.

But I hear ya, I stopped autoxing and modded outside of the rules and now have 360tq, but no header yet.

To the OP, congrats on the car and glad to see your an avid autoxer. You should write up a small review on the differences in autoxing fwd to awd, if you have time.

-Jordon
 
#17 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Just arrived yesterday! These are 5Zigen FN01R-C's in 17x9 et43. In need of some rubber soon, still debating between the RE-11 and XS.


And also, I have dyno graphs. Directly below is the STU graph with the Street tune just below that. I'm looking to get the STU graph plotted against boost, at which point I will post as well.


 
#21 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Holy HOTNESS Batman! Nice rims dude. I love those rims! remind me of the Rays 57's Very nice choice.

I just closed a deal on some 17x8.5 +40 offset Enkei RPF1's in Silver. Im gonna throw on the RE-01R's in 245/40/17. Should fit fine after a little camber is dialed in the rear with the bolts I have back there.

Do you have any camber adjustment in the rear? you might need some if you didnt roll your fenders already. But I think I remember reading that you did. Not sure.
 
#23 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

How are the 600/500 rates during daily driving? (assuming the car is your DD)

I have the 500/400 rates on my T2's now, and I run 17x10 FN01R-C's. (275's) The car is lower than stock, but not by much. I'm not getting any rubbing, but I can't go any lower, or else I will. (no fender rolling)

I want to upgrade to the 600/500 rates, but I'm afraid it will be too stiff on the street.
 
#24 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Enkei RPF1's was what I REALLY wanted...stupid 17x9's don't fit though, I'm jealous. :mad: I have Vorshlag camber plates in the rear and the T2's have a slotted strut as well for camber adjustment. I'm running -1.9 degrees right now.

I don't DD the car, but the 600/500 rates don't seem too bad. I also have the dampers set at my autocross settings which make the whole thing a lot stiffer as well. If I drove it everyday I might get kind of beat, but if you're running daily damper settings you should be fine and it shouldn't be too bad.

Yesterday's event went fantastically well. The car was damn near neutral right out of the box. Couldn't keep it clean (nor could the rest of STU), but the raw times were great. I'll have a full writeup with video/pics soon.
 
#25 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Called Steve Snow at Bimmerworks today. Ordered a set of Bridgestone RE-11's in 245/40/17 shaved to 6/32 that I will be getting mounted up on Thursday. I'll try and drive on them Friday to get a heat cycle in them, and then ready for Sunday's event.

I only shaved to 6/32 due to my own inherent laziness. The drive to events is roughly 50 minutes each way, so not bad, and I hate swapping wheels/tires at events. Also since these will have to be rain tires also, I wanted some tread to be there so I'm not sliding around everywhere. I'm not yet baller enough to have a dry and rain setup. Perhaps next year.
 
#27 ·
Re: piknockout's STU Autocross Build - 2006 STi sponsored by Agile Auto

Philly Winter Event #4 on March 22, 2009 at Citizen's Bank Park

Video: Philly Winter Autocross Event 3-22-09 Video Video by Luster - MySpace Video

So this would be the maiden event for the new setup. The big question loomed: would the car do a 180 or plow through the first turn? To help with setup, Iman (bdi) co-drove with me to get some more runs in the car and help try to set it up. He also donated two wheels/tires for the event as the borrowed wheels/tires I had wouldn't quite fit in the rear. We were running the Dunlop Direzza Z1 Star Spec in 245/40/17 both front and rear, but the fronts were nearly done and the rears had been sitting all winter in Iman's garage. This could be interesting.

We had some good competition to compare ourselves to in Cy Lee running his Mitsu Evo 9 RS which just won the Dixie National Tour with Corey Ridgick driving the weekend before, with Cy finishing 2nd and running on the Bridgestone RE-11.

On the very first run, we made it about 3/4 of the way through the course until a red flag for a golf cart near the course. That's okay though, rerun! But an amazing thing happened on that first test run...the car actually felt REALLY good right out of the box. How did that happen? Perhaps it was the lack of "understeering fairies" on the car, who knows. But the car felt great. We only made two minor adjustments to the car all day, with one more click of rebound in the rear and a little lower psi in the rear tires. Car was fantastic and a blast to drive!

First run came through with a 53.147 +1, which would end up being the run I had to stand on for the day thanks to no other clean runs. It was good enough for a 2nd in STU (Cy pulled out a clean run 54.0xx) and 18th in PAX. Had the run been clean, it would have been good enough to take the STU win and finish 4th in PAX among some good company.

What I learned this weekend is that the car setup is right in the ballpark, thanks again to everyone who helped offer advise on parts and setup, everything worked well. I've ordered some RE-11's that should be here this week and will be testing out this weekend. I don't think I'll have a chance to give them a good heat cycle before the event, so the first real test probably won't come until the A.I. event on April 11th. I can't wait to continue tweaking the setup, but hopefully there's not too much more to do and I can focus more on driving.

More to come in the next few weeks. :D
 
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