Rim size and tire question

[Hungster]

hey guys, im looking into a set of rims and tires to use just for autoX and track. Whats the best rims size and offset, as well as tire size. are 16's best for our cars with thick tires, or 17's with low profiles??? im dont know crap about tires, so yea im really interested in this. Thanks for all the help. BTW i have a 02 gts.

[dchan8]

the only reason for low profile tires is to have the biggest possible rotor for the brakes. if you're not going to change brake rotors, then get the smallest lightest rim with the widest tires possible to fit the car. i can do the calculations for you, but 225/60/15 might be your best size.

if someone disagrees with this, i'll be really surprised. i can give examples if your interested.

[Hungster]

so 15 inch rims, with 225/60 tire size????? yes please give examples, i have 15's on right now the gt alloys, i have falkens but only a 50 profile. so yea, they break to easily when i start turning.

[NoCones]

Just for autox and track, I'd get a 15" wheel with a 225/45R15 Hoosier or Kumho. 15x7.5 if you're autoxing STS, 15x6.5 if you're autoxing stock class. Offset of 35-40.

[dchan8]

Like I stated before, the only reason you want big rims and low profile tires, is so that you can fit the biggest rotor/disc inside the wheel. If you're statisfied with the stock brake rotor size and performance, the 15's inches rims should weigh the least. If not buy the lightest 15

[NoCones]

Originally posted by dchan8
and use widest tire possible, probably 225/50/15 tires(I did the calculation and this matches the stock diameter the closest).

4-225/50ZR15 Hoosier R3S03 Heat Cycled - $190.00 = $760.00


I don't know why you'd be worried about matching stock diameter for a race-only application. I'll take the lower gearing of the 225/45. There is a point at which you might get a sidewall that's too short/stiff, but the 225/45 is perfectly fine.

[Hungster]

right now im running 205/50 falken azenis, on gt rims. but this is also my daily drive tires too, they wear out hella quick, but i love em

[dchan8]

NoCones,
Do you get to top speed? if so, do other pass you up cause you're actually running a little slower? Just curious as you probably stay at redline when racing.

Hungster,
Use what you like, if you really gt into racing, you spend more, but otherwise, just try it out first and see if it's something you want to maek an investment in.
my 2 cents

[NoCones]

Originally posted by dchan8
NoCones,
Do you get to top speed? if so, do other pass you up cause you're actually running a little slower? Just curious as you probably stay at redline when racing.
Sure, I get to top speed all the time...

top of 2nd gear, that is :chuckles:

I only autocross, so true top speed is not an issue. The shorter tire may mean that I have to go to 3rd a (very) few times when otherwise I wouldn't, but the improved gearing coming out of all those turns is worth it. I think a 225/50 is actually taller than stock, so while you might gain a little top speed, but you're hurting your gearing, even compared stock. That could be especially harmful in a GT-S, where the powerband is so narrow.

Even if you roadrace somewhere where you reach top speed, if you compare time at top speed vs. time accelerating, I think you'd choose a smaller tire.

[dchan8]

NoCones,
I agree with you, for autocross, where top speed is not needed, use 45 series tire, but I looked at it as road racing where you want to keep ht car at redline all the time, so on the straights, you will hit top speed.
dchan8

[Hungster]

i liked auto X, it was fun, i want to do some track racing where i can get more into lift though as well. i have the suspension for it so yea i want to do more AutoX and track racing more than anything.

[dchan8]

track racing, i would suggest taking a class first to learn the dynamics of a car. my 2 cents

[NoCones]

Originally posted by dchan8
NoCones,
I agree with you, for autocross, where top speed is not needed, use 45 series tire, but I looked at it as road racing where you want to keep ht car at redline all the time, so on the straights, you will hit top speed.
dchan8
Show me a road course where you'll spend more time at top speed than accelerating.

Take the gearing advantage.

[Hungster]

yea i want to take as many classes as i can, but it gets expensive, thats why im autocrossing to learn more about the limits of my car.