chiketkd

iTrader: (5)

I've seen similar ST* threads on EvoM, Nasioc and Bimmerforums. Please use this thread as a place to discuss STX builds, set-up questions/issues, post results, dynos, pics, etc.

Looking to run my car in this class locally next season, but I'm already in the process of acquiring parts (taking part in the Fluid Motorsports group buy for Progress springs).

Depending on how my car does locally, I might consider a few national events, otherwise, I have a solid offer to co-drive an STU car ('06 STi).


I'll start my STX build this Fall/Winter and it will include:

• Coilovers (Bilstein PSS9's)
• 17x9" Enkei RPF1's (15.9lbs)
• Competitive ST* tire (Dunlop Star Specs or Hankook RS-3's)
• RB midpipe with the Davesport High flow 100cpi cat
• Lighter-than-stock battery (for now)
• Cobb AP?
• Possible pro-tune?

Mr. Pockets

I have run a single event this season in STX. Last year I ran the car in STU.

I switched this year from Azenis to RE-11s. Even though the Bridgestones are narrower, they provide way more grip. They've also changed the handling balance of the car to understeer in some situations. I haven't figured out tire pressures yet, though, because our only event so far was hardly typical. Right now my best guess is that the fronts have to be somewhere north of 40psi.

Here's a blurry picture of my car from Saturday:

http://s291.photobucket.com/albums/l...t=DSCF0254.jpg

chiketkd

iTrader: (5)

Ha ha. Nah, I've come to love "street tires" and will probably compete on them for a couple seasons down the road. I have a daughter that's about to go to college, and I'm going to be picking up rallyX soon (fwd car). Just want my autocross stuff to be less expensive from year to year. After the initial cost of setting up my car for STX, my annual tire costs will be around $700-$800 or so (i.e. one set of competitive 17" ST* tires which should be *fast* for 200-250 runs).

jujo

Nice! I'm planning to register for an event at some point. I'm not class prepped or anything, but it'd be great to have someone to watch or learn from. Missed your runs last time

chiketkd

iTrader: (5)

Thanks Greg. That was kind of a weird day as it was the first time I'd ever driven an STi that was fully prepped for STU. Golly was that thing fast in a straight line! I finished 2nd in PAX, but left a ton of time on the table. Oh well, story of my driving...

Pockets, to bring this thread back on track, I'll talk to Ridgick and see what pressures he used on his Evo at Lincoln. I know he's previously mentioned that he runs over 40psi. While our cars aren't identical, I know the general consensus is that the RE-11's need more psi than the RE-01R's.

trustbuddy

iTrader: (3)

how difficult is it to get involved in stx?
my main concern is that I attend church on sundays...

Mr. Pockets

STX is just a class in SCCA autocrossing. Check your local club's calendar.

Mr. Pockets

So far, I have only spent more per year than I did when I ran stock. Of course, RX-8 tires, even 17s, are a lot more expensive than those for a Mk1 MR2. :P For the difference between a $1000 set of r-comps and a $900 set of RE-11s to pay off, I'm going to have to run the class for quite some time. :P

Still, it looks like the XS is competitive and cheap. Perfect!

chiketkd

iTrader: (5)

Exactly - the XS and Z1 Star Specs are pretty cheap in 17" sizes and will be a great local event tire.

bingo

I think the incentive is the 200+ run tire life, that would mean you'd only buy one set of RE-11 to every 2 or 3 sets of Hoosiers.

Cutting tire costs to less than half will pay for springs pretty quickly.

Arrrrex-8

Mine's still a work in progress.

AST 5200's from Vorshlag (700/550) http://www.vorshlag.com/product_info...roducts_id=301
17 X 9 Wedsport TC005
255/40 starspecs
Agency power pulley
aem intake
hi-flow cat
custom single exhuast
accessport
low compression motor (need to get it in to the dealer to see if I can get a new motor, dyno'd at 167hp/119torque)
kirkey race seat with bride low max rails

I've done a couple of events and a practice so far. At the first event I did a spring swap and attempted to realign the car before the event. I never got the car aligned properly, I think I ended up over -3 degrees camber front, and nearly 0 degrees camber rear, with 0 toe both ends. I didn't get a course walk in either. Considering this and the fact that I hadn't run the car yet and had no idea how it was going to feel I was pretty happy with how it went.

A couple weeks later I went to a practice event that was held at an old airport so it was a runway style setup. In the morning it was raining, the car felt great in the rain, very easy to control. I was running the same times as a couple of wrx's and was only about a second behind an STU evo. This is especially good because I don't consider myself to be that good of a driver in the wet. It dried up in the afternoon and the car felt great and was really fast. The car had just a touch of understeer, was very easy to control, didn't do anything bad even if I did stupid things like lifting mid corner. There was only one car that was faster than me, however there wasn't a whole lot to compare too, a CP camaro. I think he was a few tenths faster. I was a few tenths faster than the previously mentioned STU evo. Other than that the there was Kevin Dietz's old solstice that he won the C-stock NT in, I think it ended up running a time almost as fast as my best. Although not driven by Kevin and running BFG R1's instead of 710's or hoosier's.

Last weekend we were at packwood, a big squarish lot, so a more traditional style course layout. My first two runs were terrible. Turns out I mounted my seat too low and I couldn't see were the cones were. This wasn't a problem at the previous track because of the runway style layout. I raised the seat up a little in grid and it made all the difference in the world. Once I could see things went much better. The car felt great, just a small amount of easily controllable oversteer, which is exactly how I like my cars setup. While I didn't win the class I was very happy with how I finished and how the car felt. We run all the ST cars together and pax them, the competition is very tough, I think I'm a pretty good driver but definitely not an elite driver which there are many of in this class. I finished better in the standings than I usually did the last few years in my STS2 miata.

So far I'm extremely happy with the car. It feels great, and is easy to drive. I know as I get more comfortable with the car I'll get faster, and there's still a lot of things I can do to the car to make it faster. The AST coilovers are great, the car is very balanced and easy to drive. I daily drive it and the spring rates work great on the streets also. On my third run fastmike lillejord went for a ride with me, he said the car felt really good and really liked my setup. I hope in the near future to get some of the fast drivers to drive the car so I can get their impressions and see what the car is capable of.

chiketkd

iTrader: (5)

Interesting set-up Arrrrex-8. The Vorshlag AST coilovers are very nice. Do you run on concrete sites a lot? Those spring rates seem almost road race stiff.

fastmike

I have been wanting to get in a STX RX8 for awhile and yours felt really good.
I like my RWD cars set up just like yours.
Course had a few spots where you were out of your power in 2nd a little bit but I am still VERY impressed with these new "street" tires and how much grip in all directions that they give.
FM

Arrrrex-8

No concrete. The springs aren't really that stiff once you calculate the wheel rates and bounce frequencies, which is really what matters. Plus mines a GT so its a little heavier than the sports. And even though I've lost quite a bit of weight I'm still a big guy, about 200lbs, that adds some more weight too. All of which lowers the bounce frequencies. I'm still on the stock sway bars. Which I may change at some point, but if I do they will be smaller than what most people use. As of right now I'm very happy with the balance and it doesn't feel under sprung, so the main reason for new sway bars would be for adjustability, and maybe slightly more roll resistance if I decide I need more. I'm going to run a few more events before making a decision on the sway bars to see if my opinion changes.

I think the whole stiff springs/soft swaybar vs. soft springs/stiff swaybar thing comes down to personal preference. I prefer to run stiff springs as they provide benefits in other area's that stiff swaybars don't. Such as acceleration, braking, the suspension is less likely to bottom out over bumps, and better suspension articulation. The stiffer the sway bar the less independent the suspension is from side to side. With a good set of shocks properly valved the downsides of the stiff springs can be minimized or negated. And I just like how it feels with stiff springs, and this type of setup seems to suit my driving style.

I actually feel like the rates I chose are a compromise for daily driving comfort. My STS2 miata was substantially stiffer than the RX8 is. I tried 4 different sets of spring rates on that car, the last set which I felt worked the best for autoX were a bit harsh for daily driving. When deciding what spring rates to use on the RX8 I knew I wanted to keep it more daily driver friendly than the miata ended up being. So I used the knowledge I learned from the miata and chose springs that gave me similar bounce frequencies to the ones that I felt were the best compromise between daily driving and autoX that I had experienced on the miata. So far its turned out pretty much how I was expecting. Except the AST's work even better than I anticipated, I may have chosen stiffer springs if I knew they'd work as good on the street as they do.

I left out one important note in the first post. The car is a lot of fun.

Arrrrex-8

I think you guys run in the morning and we run in the afternoon next weekend. If you stick around for the afternoon, you are welcome to drive the RX8.

chiketkd

iTrader: (5)

So what are the price points for the different AST coilovers for the RX-8 by Vorshlag?

Btw, do you have the latest version of the Cobb AP? Have you tried the launch control feature? Tried it the other day on an STI...sweet!!!!

chiketkd

iTrader: (5)

So what catbacks are people going with in STX?

I'm happy with my current MS dual, but wanted something even lighter that would flow well and still have good sound suppression if/when I add a high-flow cat and headers. I've gone ahead and purchased the Corksport catback which is 11lbs lighter than stock but doesn't cost an arm & a leg like a titanium catback.

GeorgeH

iTrader: (2)

I'm running the Corksport. I like it (in BS trim so far) but it is loud. When I first installed it, I also had the OEM cat replaced under warranty and the combination was quite loud, but in a good way. It has mellowed with age a bit, but I still leave a few blankets in the trunk to quiet it down on the freeway.

The sound, even though it is loud, is fantastic. No ricer sound, just pure rotaty. I get lots of compliments on the sound.

BTW, the guys at Corksport are great. Their shop is in my hometown and when I had an issue with the first exhaust they sold me, I just drove in, they put the car up on a lift and swapped it out, sent me on my way.

chiketkd

iTrader: (5)

Cool - thanks for the info. Looking forward to getting mine! From the videos I've seen on Youtube, it seems quieter than the 3" Turbo XS, Exoticspeed, etc.

jones75254

iTrader: (2)

I chatted w/ Chik via PM for some clarification and figured i would post here just to contribute to the thread. To be fair, i have yet to autox my car but have tracked it and am really looking forward to getting involved in the whole autox scene. I am waiting until after i move to San Diego here in couple weeks. I didnt tailor my setup to fit the STX class, its just the class my current setup falls under Here it is:
-Tein S springs over Tokico Dspecs
-17x9 FNO1R-C w/ 245/45 RE-O1R's
-RP supercat w/ Greddy Sp2 catback
-Racing Brake slotted front rotors, SS brake lines F+R
-Exedy Stage 1 clutch
-AFE Short Shifter
-EfiDude reflash

GeorgeH

iTrader: (2)

Welcome to STX, good luck, and, above all else, have fun!

chiketkd

iTrader: (5)

Actually, reviewing your pm's and the mods you posted in this thread, you didn't mention the clutch before. Unfortunately, aftermarket clutches aren't allowed in ST. As you're new to autocross, I'd talk to your local competitors and if they're okay with it, then run STX. Otherwise, the clutch will put you in BSP.

GeorgeH

iTrader: (2)

Good point. I know I wouldn't mind if a competitor ran an aftermarket clutch, at least at a local event.

chiketkd

iTrader: (5)

+1 As he's a novice it shouldn't be a big deal. If he intends to compete at National events then that's another story.

TopGear8

iTrader: (3)

Ok so I have a question for you guys. Right now I am running in STU (I know this is a STX thread, but close enough) Right now I'm running Megan Coilovers just because I got a good deal on them, but will be switching to the Stance GR+ soon. I'm running 275/35/18 Falken Azenis RT-615, with RB sways front and rear. And the car just has too much oversteer. I've changed dampening settings, tire pressure, and it still is just too tail happy. Even down at roebling road where the speeds were much faster, bearly any understeer, but again, too much oversteer.

So I'm thinking about switching back to the OEM rear sway bar. You guys think this will solve my oversteer problems?