The STX thread!
 

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?

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

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).

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 :)

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... :lol:

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.

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

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

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!

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

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.

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.

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.

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

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.

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.

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? :D: Tried it the other day on an STI...sweet!!!! :cool:

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.http://corksport.com/store/image/fqa...ust_System.jpg

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.

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.

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

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

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.

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

+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.

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?

What are your current camber settings F&R? Going down to a smaller rear swaybar could help. If that doesn't work, you could run no swaybar altogether. Many STS miatas are set-up to run with no rear swaybar.

One piece of advice before you dive into making several changes, get a more experienced driver than yourself to drive your car. Your car may not be as loose as you think - sometimes a change in driving style is all that's needed. ;)

^-1.8 in the front and -2.0 in the rear. I've had more experienced drivers drive it too and they have the same problem as me.

http://vimeo.com/4343863

Here's a video, to show you how around even some of the lower speed corners in 2nd gear, it likes to slide.

Megans have an 8k/6k split. I'm not surprised you have oversteer issues.

As a first test. just disconnect one side of the rear sway bar. It's easy and you'll know right away if this takes it too far or not.

^I will try that at the next event. The Stance GR+ that I will be getting soon are 10k front and 7k rear. Mr. Pockets requested a 6k rear and was happy with it, but also talked about trying out 5k in the rear to see the difference. I was origionally planning on going with the 6k in the rear as well, But do you think it would better to go down to 5k?

Not sure. Others here have more experience setting up the RX-8 - I'm still on my BS setup.

I intend to go with the KW Variant 3, which uses a 455/258 split. That's a 56% split, which is halfway between 10/6 and 10/5. I suspect either could be made to work, but perhaps others will chime in here.

I would recommend the 6k. That's what I used last year with the same tires. I will also point out that I've still been running with stock bars, front and rear. I have no idea what those RB bars will do to your balance compared to mine.

OK, I've finally got my fist STX-specific purchase on the car. 17x9 wheels (a bit heavy, but the price was right) with 255/40-17 Toyo R1-Rs. I realize the tires may be a somewhat contreversial choice, but I liked the reports that the R1-R does well in the rain (I'm in the Pacific Northwest and have experienced rain on more than one tour) as well as good longitudinal traction (should help on corner exit against the AWD cars). If they force me to be a smoother driver then so be it.

I probably would have bought AD08s but I got impatient - wanted the tires for this weekend's NW Region Pro & regular solo events at Packwood.

Rest of the car is still pure B-Stock. I expect to get schooled by Karl & Amy in their WRX, but you have to start somewhere.

Car looks great George. Yeah Karl and Amy Coleman will be a great sounding board to see where you stack up!

I didnt figure an upgraded clutch would pose any advantage due to no real additional power adders :dunno:. I must have missed that one when reading through the rules.

Oh well, like it was mentioned, its not like i am competing on a national level. Im just a rookie

I'm running the RB front and rear bars with 8k front springs and 5k rear springs. I usually run full-stiff on my front dampers and full-soft on my rears, and the car is very well balanced. 10k fronts plus the very-stiff RB front bar might be a bit stiff for street tires, but that will of course depend on the surface. Either way, I think you could dial in either the 6k or 5k rear with some shock / camber / tire pressure adjustments.

Exactly - no performance advantage per se, but still not legal to the letter of the rules. However, when you get to San Diego, go spectate at a local autocross, talk to few competitors and see what they say. Most shouldn't care especially since you're a novice. Main point though is to have fun! This sport is addictive...and can get expensive really quickly! :lol::lol::lol:

I guess I should post this nugget over here for you guys that have not looked at the June 09' SC, and plan to run STX/U.

For you Racing Brake fans, they just started advertising in SportsCar magazine (SCCA members get it)..... In the June 09' issue (pg 43) there is a discount code for 10% off Racing Brake products. SC0609, good until 7-31-09.

I took advantage of BHR's sale a few weeks ago and put Hawk HP-Plus pads on my car last weekend. Tomorrow will be my first event with them.

I can tell so far that they definitely require less pedal effort to stop the car. Will it be enough to allow me to use my admittedly odd heel-toe method and downshift to first, if I need to? Time will tell.

^I'm running the HP+ as well, So far i've ran 3 events on them, and one day at the track. They are a definite improvement, but love to squeel when they are hot!

My avatar would seem to suggest you're right. And yet, I will keep trying! :D

We had events Saturday and Sunday.

First, I took FTDI both days. That's a clean sweep of the season so far after three local events.

Let me tell you, the RE-11s are amazing. I know I'm not reaching their full potential yet, because I have no real complaints about the car's handling. I know I refined it a lot last year, but come on. If I'm not complaining, I'm not pushing it hard enough. It's not rotating as much as I'd like in low-speed corners, but I'm not sure I'd want to trade that for the excellent high-speed manners the car has right now.

As Mark said above, the Hawk pads are too much for street tires. He's right about that one. I'm going to give them another couple events, just to see if I can use them better, but they do overwhelm the tires quite easily. Braking with the stock pads, leaning on the ABS, I get consistent pedal feel and stopping distances. With the Hawk HP-Plus pads, the brakes seem to bite too suddenly. The pedal isn't consistent and I am surprised by how long it takes to stop. If I don't get them figured out better on my car, I'll swap back to stock.

No pictures that I know of so far, sorry. I did shoot video on each of my runs, and I'll try to get something up tonight.

Awesome results Pockets! What pressures did you find work best with the RE-11's F&R for your set-up?

I wouldn't call them 'final' pressures, but so far I'm using 40f/38r. The RE-11s seem to need more pressure than I'm used to.

I'm not convinced those are perfect pressures yet because we still don't have what I would call useful temperature data. I might need more or less air or more or less camber to get the most out of these tires.

Ive done about 5 events on my nitto nt05's and the grip level seems to be the best when the pressures are at 32f/30r. Anyone else running these they went on sale a lil late so alot ppl have been running the re-11 or z1, anyone try the ad08 advans

As I said, I don't have pictures from the event, but here's a video I put up from Saturday. I haven't had time to put one up from Sunday yet.

http://vimeo.com/4726254

Mr. P., congrats on your FTDI. That’s an interesting surface you run on there.
I had mixed results at my NW Region events.

On Saturday, we had a pro-solo style event. Each course was a little under 30 seconds long. Conditions were sunny, cooler in the morning and perhaps 80 in the afternoon. I lined up against Karl Coleman (or rather, he lined up against me!) in his well-prepped WRX, with me in my B-Stock prepped RX-8 running 255 Toyo R1-Rs. This would prove to be an interesting test.

Not surprisingly, Karl completely owned the launch. It wasn’t even funny. The announcer said my 60 ft times were 0.5 seconds behind Karl. My reaction times started in the .7xx range, but I eventually had one .5xx. I’m not saying my 60 ft times are representative of what a good RX-8 driver could do with another 20 hp on tap, but I never bogged the car and I think we all know the WRX will have our number at a pro-style launch.

The rest of the course(s) wasn’t much better for me. You know the old adage that a race track is a bunch of drag-races connected by turns? Well, I never experienced a Solo event of any kind that more closely matched that description. There were several long pulls on the throttle, and given that the course was under 30 seconds long, well, you get the idea – just a couple of token turns & transitions connected by a flat foot. Fun as heck, but talk about a course that liked Hp…

So, in the end, I was nearly 3 seconds down for both courses combined (54.7 vs. 57.6). I should point out that Karl had FTDI that day.

On Sunday I did much better. It was a more typical solo course with lots of transitions and sweepers. I closed the gap to less than 1.5 seconds over a 58 second course (56.6 vs. 58.1).

I’m actually pretty happy with that result. Considering my level of car prep, and the fact that Karl is a more accomplished driver than I (Karl is a nationals trophy winner), I think the RX-8 has a shot in this class, at least for regular solo-style courses. Of course, it’s just one event, and Karl was on last year’s Star Specs, etc. But then, I’m just learning to drive the R1-Rs, so…

I just ordered KW Variant 3s. It will be interesting to see how much time I find with these. I’m not expecting miracles, but it should help close the gap.

Interesting write-up George. What are your plans for power? High flow cat, headers, AP?

2wd cars will always be at a disadvantage in pro solo, but that's the nature of the beast. Have any pics from the event? Hopefully, with seat time and set-up improvements, the gap between you and Karl will close even more. It definitely will take 1-2 years of development before we start to see the RX-8's true speed in STX. In a regular solo, it definitely seems like it can be a contender in the class.

When I get the $$$, I'll probably go for the AP + cat for the power tweak, with the header coming last. Car made 180 Hp, corrected, on a Dynojet a few weeks ago with a K&N drop-in & cat-back, so the motor seems reasonably strong.

I've been debating, though, wether I should get the AP or cat first. I know they work well together, but I'm not sure which would give the most imrovement stand-alone. :dunno:

If you have to choose one or the other at this time, I'd take the AP. The increase in hp/tq should be noticeable across the rev band and you'll have other features to play around with like launch control. :)

Once you have the $$$ to add the high flow cat, I'd flash back to the base (stock) map and get a pro-tune.