I've been autocrossing for 2 seasons on my DD summer tires and they're totally bald now. I want to get a designated second set of wheels / tires just for autocross, but I'm not sure where to start...

The first problem is what size, and what kind of wheels to get. Smaller wheels are generally lighter so I'm obviously not going to buy 20" track wheels, but should I get 16, 17, or 18" wheels? Max width for my class is 8". After that, I don't know what size tires to get on them since it doesn't matter if the speedo is off, I just want whatever will give best performance (max section width is 245mm). I'm thinking something with a small overall diameter would be best so I can see a little benefit of increasing the FD (from the lower circumference), so the gears will be shorter.

Then it comes down to what brand / model of wheels / tires. I was looking at R-Compound tires which would give me the best performance, but the sizes are really limited, and they're ridiculously expensive.

What do you guys think? I need pointed in the right direction.

 

If the max width in your class is a 8"...I'm assuming Stock Class, then a 255/45/17 is probably not a bad size to run on all 4 ends. What size do you run stock is a better question?

 

18x9 or 9.5 all around will fit ur 2nd gen. Enkie has some really light weight rims.

U can run 245/45/18 on a 18x9.5 front with 275/40/18 on a 18x9.5 rear on the same size rim width all around. It wouldnt mess with ur AWD.

And that might increase ur choices of tires...

 

It's SCCA autocrossing, and I'm in the STX class which has the 8" width limit. I'm running 19" x 8.5" wheels right now with 245/40 Kumho Ecsta SPT's.

 

Like I said, the width limit is 8" (I know it sucks!)

 

Wow, just re-read the STX class rules...the 245 max width limitation puts my suggestion way out the window.

 

Pure speculation BUT...245/40/18 seems to be a very popular size...I think you'll find a good rubber in that size+ benefits in gearing from decreased diameter + sidewall stays the same size as your 19's, nice and stiff@ less than 4inch.

 

^^ Reading comprehension>you.

 

I kno I just got owned by that lol.

mehh, I think u should just skip that class, and look for one that allows u to run 10" rears =] lol

like others said then 18x8 245/40/18 or 17x8 with 245/45/18 will prbbly be lighter.

 

I'm thinking 17x8" for weight and price (Kumho Ecsta XS most likely for price/performance ratio)

245/45-17 is 4.34" sidewall ($504/set)
245/40-17 is 3.85" sidewall ($572/set)

Advice on pros/cons of the different sidewall heights (if that's the biggest factor there between the two options)?

How about wheels? I'd love some Enkei RP03's but would rather not spend $1,200 on them. More affordable alternatives (looking for ~$800 maybe)?

 

sidewall height affects sidewall flex and with some tires steering feel. That 245/40/17 is a pretty small tire! ie: s2000's and new miata small.

 

yea 40 profile on 17 tire will leave u with wheel gaps big enough for me to hide in.
Rotas...
http://www.racinglab.com/rowhto175.html

 

Stick with the 245/40/18 and get Dunlop Star Spec tires, extremely popular right now with auto-x'ers. As for wheels, its going to be tough to find light 18's for less than $1200. Rota's might work (if they have an 18x8), MB Motoring Battles come in 18x8. If you're restricted to 18x8, try finding a full set of front 350z track ver1 wheels (rears for that set are 18x8.5), they are very light and strong.

 

^ Awesome suggestion on wheel & tire. It's a $360ea needle in a haystack wheel, so if you find a set, hold on for dear life.

 

If you can't find the 350Z track wheels sold as fronts only, it would be worth it to buy two staggered sets and then sell the rear pairs as a set which is also desirable for other people out there. You're talking some serious spendage though for stock wheels by that point and you risk sitting on the extra set too.