Any new autocross tires on the horizon?

[BlackbirdM3]

This is a good point as well, at some point the weight/resistance/extra track width of a wider tire/wheel will slow you down, however I'm surprised you feel that a 10" wide wheel is that point, seems that even the 100hp miata guys find 9-10" wide wheels with 225 street tires or 275 wide slicks are still faster than anything narrower.

One other thing to consider would be gearing advantage, the 235 on a 17 that you mention (I assumed 235/40/17) is 24.4" tall while both the Hoosier 275 and the rival 225 are only 23" tall, that helps lower your center of gravity and also provides a bit more grunt out of corners vs the taller 235

of course if you're already hitting the rev limiter in 2nd regularly then the shorter tire probably isn't going to help as much but if you typically aren't hitting the limiter in 2nd the gearing may help!

The Miata guys are all running 13 inch wheels, with light R compounds, big difference. If you put a Miata on 17x10s, it would be a slug. 13x10s entirely different story.

Will

[klodkrawler05]

The Miata guys are all running 13 inch wheels, with light R compounds, big difference. If you put a Miata on 17x10s, it would be a slug. 13x10s entirely different story.

Will

That was exactly my point, one of the previous posters said his 17x8.5's were almost as wide as he thought anybody would need on an e30. I was suggesting that a 15x10 would be even faster. Most of the miata's I saw at nationals this year were all on 15x10's not the 13x10s?

[R3Z3N]

^For my car, I can not go smaller than a 17in wheel due to my brakes, but I am not debating my car vs the OPs needs, it was a statement to what works for me.

As we all know, biggest problem on our car is fitting wide rubber up front, and usually the E30 likes a square setup, which limits us drastically.

[ajhostetter]

I just ordered a set of RS3's with 15x8 TRM C1's. I'll let you guys know how they turn out this season.

[Wh33lhop]

That was exactly my point, one of the previous posters said his 17x8.5's were almost as wide as he thought anybody would need on an e30. I was suggesting that a 15x10 would be even faster. Most of the miata's I saw at nationals this year were all on 15x10's not the 13x10s?

Yep, 15 is the miata size of choice. Nobody's advocating 17s here will.

[BlackbirdM3]

That was exactly my point, one of the previous posters said his 17x8.5's were almost as wide as he thought anybody would need on an e30. I was suggesting that a 15x10 would be even faster. Most of the miata's I saw at nationals this year were all on 15x10's not the 13x10s?

I'm pretty sure all the guys I run with are on 13s, and they are all very fast. I have no doubt that if the smallest wheel you can run is a 15, going way wide will find you some time, assuming you can get them to fit under the fenders. I'm halfway tempted to go pick up a set of Kosi R1s from Tire Rack to find another inch of width, on the wheels. I like the Kosis, but I don't know that I really like them as normal wheels on my car however. That said, I like the stock M3 15s, but they are a pain in the ass to clean.

Will

[Wh33lhop]

I'm pretty sure all the guys I run with are on 13s, and they are all very fast. I have no doubt that if the smallest wheel you can run is a 15, going way wide will find you some time, assuming you can get them to fit under the fenders. I'm halfway tempted to go pick up a set of Kosi R1s from Tire Rack to find another inch of width, on the wheels. I like the Kosis, but I don't know that I really like them as normal wheels on my car however. That said, I like the stock M3 15s, but they are a pain in the ass to clean.

Will

You run with UFO which is known for super tight courses. The really fast track miatas mostly run wide 15s, and surprisingly are able to tuck a lot of tire under their fenders.

I think you mean Kosei K1s. Good wheels, and you will be faster given the same set of tires.