Hello,

I know this autox season is pretty much over, so I am just taking the time to drive in as many as possible, learn the car, and have some fun. However, for next season (hoping they don't change too many rules) I am looking to go to STU so I have some questions on what is allowed/what I should get (feel free to correct me if I am interpreting the rules wrong):

1.) Tires have to stay stock size and have to be able to be used on the street, so I am probably going to be going with RS-3's. How long would a new set of tires last me if they were mostly used for autox with not much street driving? Would I be able to take the competition tires off and out on my all-seasons or would that ruin the alignment?

2.) I have a set of AMR coilovers on the way. I won't install them yet as I have other things that I want to do to the car concurrently with them to maximize performance and minimize trips to the shop (alignment, corner balance, etc) What other suspension mods should I go with? Both sway bars? Camber plates? Bushings? Rear strut brace?

3.) For wheels, and related to the suspension setup, am I allowed to go down to 17"? I would go with a 9" wide wheel, just looking to save some more weight and cost of wheels/tires. Would that be beneficial or would there be a greater chance of sidewall deflection, especially in combination with the suspension mods? Would 17" even clear the brakes?

4.) I will be getting an exhaust, intake and tune but otherwise I can't touch much, not even the intercooler.

5.) What's the best way to keep the engine/turbo cool, both during runs and in-between? That sucker gets hot!

6.) Weight reduction; I know we really can't touch much but what are the good ways to get rid of some weight, especially in front? I would like to do seats and harnesses but would prefer that they be the same, and while I don't mind having a fixed back, my passengers when I daily drive the car might want to adjust...any suggestions?

Thanks!

 

I was placed in STU because of my short shifter. Since I only ran once, I won't be of much help...

I think you have to stay with 8.5" wide or you'll be placed in a different class. I don't think my car got that hot, but I used a 2 gallon sprayer that I got from Home Depot, filled it with ice water, and sprayed the intercooler, radiator, oil cooler, and tires in between runs.

Good luck and have fun!

 

Reference this for your build.

http://scca.cdn.racersites.com/prod/..._Rules_May.pdf

 

Nice! You'll learn a lot about driving. Mostly: That you don't know how to drive as well as you thought you did. We were all there at one point.

The Hankooks are a decent choice, but most people in my region with heavy cars (Evos, STIs, etc) prefer the Star Specs. The Star Specs will last slightly longer and do slightly better in the rain, but no high-performance tire is going to last as long as a typical all-season tire. About 100-150 minutes of AutoX and 5-10K street miles is doable if you don't overdrive the car. Less AutoX time = more street miles, etc.

You can swap wheels/tires at will without worrying about changing your alignment. In fact, if you have the space and funds for two sets of wheels and tires, definitely do that.

I'd install the coilovers now. You will have to redo your alignment and corner balance with the coilovers anyway, so might as well do it all at once. Definitely get camber plates to go with the coilovers so you can get the alignment you want. Lots of camber, zero toe. Sway bars might be reasonable, but they're not necessary. Remember that it's very easy to go too stiff on the swaybars. A lot of people here prefer more spring to more bar.

Bushings are a last 2% improvement type thing. Forget about strut tower braces for now, because they just won't make a difference.

Disclaimer: Always read the rules top to bottom before buying parts. That said, in STU you're allowed any width/size wheel you want as long as you only mount a 245-width or narrower tire. Generally, wider wheels are more supportive for a given tire. 9.5" is the widest you can reasonably go with a 245-width tire, so 9.0" or 9.5" is your best bet.

Correct. You can't touch any pipes after the turbo, including the intercooler. Also keep in mind that you can't alter the boost controls in any way, so be absolutely sure your tune does not change the boost levels. Your tuner won't like this and might try to talk you into cheating because "no one will ever know". Don't be that guy.

After each run, leave the car on and open the hood. Don't turn it off and you have nothing to worry about. These are 60-second runs we're talking about. Grab a 1-2 gallon garden sprayer from home depot and spray down your intercooler before runs. Also your tires if they get too hot.

Honestly, don't worry about it for now. For the next year or so, your biggest gains are going to come from seat time. Both driving your own car at events and going for rides with other people. Make friends with the fastest guys there and have them come for rides with your or drive your car. All of this will pay more dividends than all of the mods you can afford.

That said, for easy weight reduction in STU you're looking at: Lightweight battery (~20lbs), lighter wheel/tire combo (~20-30 lbs if you're lucky), seats (~10-20 pounds in the X?) and going on a diet (????). In other words, don't spend money on weight reduction, but if you're buying parts it pays to look for something light.

Have fun.

 

Construct, thanks for the vast array of info!

One follow up then, will 17" wheels work well with the 245/40 tire (there's nothing lower profile in that size unfortunately)? Or will there be too much deflection of the sidewalls under extreme loads and cornering because I took off 1" of tire diameter? And will a 17" tire even clear the stock X brakes? I am definitely interested in going with a 9" wide tire, just trying to determine diameter. I also was lucky to purchase the car with two sets of wheels and tires (RotaGForce and stock Enkei) so I will be keeping one set, selling another and then purchasing these wheels to have better performance/looks.

Edit: Nevermind...found out that 17's won't clear the brakes...