A Few Questions for STX

[Areddi]

A few questions that I am looking for some guidance on. I am coming into my second autocross season, and ran mostly with local clubs last year in my Miata. I did do one SCCA event though, and plan to do more of them this year.

I know this car is going to fall into STX for me, since I will be modifying, and I have been scouring through the rules pretty extensively to wrap my head around everything that is allowed. I had a few questions to put up on here so some of the experienced SCCA guys can help clarify some things for me, and also some general questions related to this car and whats mods to look at:

1. Cat-backs are clearly allowed, but my questions relates to the front-pipe on this car. SCCA rules seem to indicate that you can go from 2 cats to 1 if it resides within 6" of one of the originals as I understand it? On the twins, would going with a catless front pipe, i.e. removing one of the cats but retaining the one in the header, fit within this restriction? Does anyone have experience with this change yet?

2. I am thinking of just buying another set of factory wheels and throwing star specs on them. From what I have been reading, the 17x7 is wide enough for this car, though some guys seem to be going with an 17x8. I am on a budget, so I might look for used STI wheels in a 17x8 or something to that effect if that is a better option This is more of the guidance question if anyone has experience?

3. As far as suspension, people have been saying that the factory stuff is pretty good already. How important are suspension changes going to be to be semi-competitive and my local SCCA events? Obviously every region is different; I am not planning to go to nationals or anything, so just wondering if STX is like STR where if you are not modified out you're going to get stomped?

4. STX in general; fairly competitive? My experience was with STR where the flavor of cars was pretty small. STX seems to have a larger pool of cars to compete against, which is cool. Any of you guys enjoy the class?

Thanks in advance for the help. I have searched around and have seen bits and pieces here and there, but I wanted to bring my questions home and see if anyone with more experience than me could shed some light for me.

[Kido1986]

You will definitely need more wheel/tire to be competitive in STX. Look into 17x9s with 245s. 17x7 will be alright but you will leave a lot of time on the table (Ill be running in RTR so Im stuck).

You will definitely want more suspension as well to go with those tires. A GOOD coilover or use a good spring at minimum. KW V3s, ASTs, JRZs, Ohlins. If you want to save money, go with a set of RCE Springs and some Koni struts. Just dont fall for the cheaper coilovers. Stock just won't hold to speed in the corners you'll need.

In florida, STX is hugely competitive with RX8s, 3 series and FT86s. A bunch of guys on here are prepping for STX

Oh, and something that STX will NEED to be competitive I feel is a tune, it will help the TQ dip which will be a huge help for these. I wish I could do something about the dip while running RTR Certain track layouts, I get killed by torquey cars since I have to wait for power.

[whataboutbob]

I've been running STX here in San Diego for all of 2012.

2) I ran the stock wheels with some 1st gen Michelin Pilot Sports for most of the season after I destroyed the OEM tires.
I've got a set of 17x9 RPF1s on order that I plan to match with 245/40R17 Z2 Star Specs. If you are on a budget I'd say 17x8s is a good choice as it will allow you to run a 235/45R17 tire.

3) I ran with the stock suspension all season and my tires paid dearly for my tendency to overdrive the corners and the resulting understeer. I still need to work on overdriving the corners, but I've made some suspension mods after the end of the season.
I've already put RaceCompEngineering springs on the factory struts, and replaced all of the front LCA bushings with Whiteline stuff. I've also put a new 20mm Whiteline adjustable swaybar with adjustable end links on, and added Whiteline camber bolts. There are additional suspension mods in the pipeline for the front and rear end of my car.

4) Yes. I've run against WRXs, RX-8s, 240SXs, IS300s, a few FR-S/BRZs, etc. There are a lot of good drivers in my area, and I realize I still need more seat time.

[celica73]

I'm running STX-Lite with my car. I just don't do this enough to justify the expense of all the mods I want.

My current setup:

245/40-17 Star Specs on 17x8 Enkei's (RPF1)
Double camber bolts per side to give about -2.3 degrees of camber in front.
Muffler delete on race day

Planned mods:
Stranoparts front sway bar.
More aggressive brake pads

That's it for now. I'd love to do more, but it's not in the budget.

In my area, that puts me on the pointier end of the stick for results. At the last event, it was good for 1st (co-driver) and 3rd (me) in STX, with an RX8 in the middle (0.2 seconds separated me from first). Overall PAX index we were 4th and 6th. Not bad. We were 8th and 11th on raw time (top two spots were a shifter kart).

To add perspective, the top index car was an STS Miata (Kraig Klippel, 6th at 2012 nationals in STS) and he was 1.8 seconds faster on index.

So, on the one hand, I finished well overall, on the other hand, I got whipped. I don't pretend to be the driver that Kraig is, nor do I pretend my car is prepped as well. That was also just my 4th autocross after 5 years off.

DC region is much deeper than my area, but I'd say that your initial level of competitiveness will be more driver dependent that car.

[mla163]

I'll be running in DC. RTR, I assume.

I'd start there (unless you are already bumped) to get a feel for the car. I'd build an STX car, but at the pointy end of prep, you end up with either a compromised setup, or an uncomfortable daily driver.

Wheels and tires - as big as you can go
Suspension - coilovers, I'd look at the KWs
Exhaust - start with the catback and move in from there. I wouldn't worry about cats just yet.

You will see the biggest benefit from tires, then suspension, then brakes. I wouldn't worry about power until you are comfortable with the car

Also, talk to Sam Strano about setup. He can help you out.

[Kido1986]

Originally Posted by mla163

Also, talk to Sam Strano about setup. He can help you out.

Very true. Just remember that if you use him for info, try to order your stuff with him. He's a great guy for help but if we abuse that without giving back, he could understandably not want to be so free with info in the future.

[des]

Originally Posted by Areddi

Obviously every region is different; I am not planning to go to nationals or anything, so just wondering if STX is like STR where if you are not modified out you're going to get stomped?

Without knowing who's in your region ...

You will get stomped, but not because of the car. You're fairly new, and seat time ultimately is the best mod you can make. Someone like Kraig Klippel in your stock car will beat you in your modded car.

That said, there are a couple of mods that will help with tire wear and make the car more fun without spending a lot of money or making the car nervous and uncomfortable to drive.

1. Camber bolts, alignment and front sway bar. The bolts are 10 bucks or so. Max out the front camber. Don't touch the rear toe until you race the car and know what kind of behavior you're trying to fix. Get the biggest front bar you can -- Strano's is, for now, and cheap to boot.

This is your most important mod because it allows you to put power down much earlier than in stock form. You won't be chasing the tail of the car because one wheel gets light and the Torsen shifts the power.

2. New tires. If you stick with stock wheels, go for the 235s. If you go for a wider wheel, the class standard is 17x9 -- in which case you'd want at least a 245.

This car with a big bar and 17x9 245 Dunlops will be quite competitive unless you have a national champ in your backyard. (I'm nobody's idea of a hotshoe but am only a few tenths off our local Nationals STX trophy winners.)

Coilovers and a tune are *big* investments.

[mla163]

And as far as tires go, I'd wait until the new Dunlops come out. That's what my money is on.

[Scooby South]

Originally Posted by Areddi

A few questions that I am looking for some guidance on. I am coming into my second autocross season, and ran mostly with local clubs last year in my Miata. I did do one SCCA event though, and plan to do more of them this year.

I know this car is going to fall into STX for me, since I will be modifying, and I have been scouring through the rules pretty extensively to wrap my head around everything that is allowed. I had a few questions to put up on here so some of the experienced SCCA guys can help clarify some things for me, and also some general questions related to this car and whats mods to look at:

You are allowed to swap out the whole Exhaust...including both cats and replacing it with one with in 6 inches of the furthermost cat...most Cat pipes will allow this.. MotiveConcepts, perrin, Nameless...all are with the ruleset. my plan..run catless headers...overpipe and catpipe... that falls within the rules..

Rules allow up to 9in wheel . Personally I am using a 17x9 allowing up to 265 tire per the rules.. I have 2 sets of 17x9 wheels, one set mounted with 245's...and the other will be 255's.. Weight becomes an issue here.. to allow the best perfomance.. since you don't plan to go to nationals and you want to just learn.. I reccomend a good/light 17x8 with a 245 competitive tire ... RS3 Hankooks, Dunlap StarSpec, are the 2 leading tires in class.. that way you can still run your stock suspension and not have any worries.

This is up to you.. The more adjustable it is...the better... so you can dial in differnent conditions... Stock Suspension will suffice for your level of competition...I would suggest the possibility of changing the sway bars to enhance your experience.. and for better car control/handling.. and its the cheapist suspension mod you can do.. I also recommend a good alignment.

Very competitive... but also a great chance to learn your vehicle..and trust whats its telling you..

no problem... if you have any other questions LMK..I will be glad to help.. I hopefully answered all your concerns..

thanks

Bill
STX #86

[xwd]

1) right now there aren't very many headers available. The cats are close enough you could replace either one. My guess is eventually replacing the header with a catless one and using a front pipe with a high flow cat will be the way to go. Probably marginal HP gains.

2) As long as you like the style and colors its hard to beat the Enkei Rpf1 in either 17x8 or 17x9 for price and weight. Another option in 17x9 is the Mach V Awesome. Only the 04 STI rims will fit since our cars are 5x100 bolt pattern. It's not too expensive and weighs under 18lbs.

3) You could get springs like others have mentioned such as the RCE ones. Swaybars might help as well, there are a number of them out there right now. My two picks are the Strano one and the Whiteline 45Z front bars. Although if you don't want to do springs you can go bigger in the front and rear with the Eibach and Hotchkis ones, they both have a really bing front bar which makes doing a rear necessary as well. Ground control makes a reasonably priced coilover kit using Koni shocks.

4) Top cars are E36 BMWS, RX8s, WRX. A lot more variety than STR.

[Areddi]

Awesome thanks for the comments guys, that helps me get my head wrapped around a lot of it. Like I said I am not looking to win my class yet or anything, but I would like to not come in last haha.

I do like the RPF1's, and they're not too expensive, but budget minded options may take over. Guess Ill see what I can do.