[Silver Bullet]

I used to run kumho's on my old '90 but didn't know if they even made the new tire sizes. Can you use GS rims 17x9.5 and 17x11's?? Do they work well??
Would love to get an extra set of ZO6 rims and mount good set of race tires to them.

 

[RFC]

Using G-Force R1As - 275 40 17 front, 295 35 18 rear. Fantastic deals on these at tire rack while they last (discontinued).

My understanding is GS wheels fit.

Bob

 

[VetteSpace]

I've got a set of CCW wheels and BFGoodrich G-Force R1A's on order with John at CCW. Should get them any day now. I'll switch to the new Kumho's after these tires wear out. The wheels are 18" x 10" Front and 18" x 12" rear. /phpBB/images/smiles/icon_smile.gif
They'll be used primarily for the track and I'll swap to the stock wheels and tires for the street.

Andy

 

[Dave Schotz]

I use either the Factory Wheels, or Circle Racing wheels (Factory Sizes). I use Kumho's up front, and Hoosiers on the rear, temporarily until the Kumho 18" Tires arrive. Which should be in the next couple weeks! /phpBB/images/smiles/icon_biggrin.gif

Take Care,

 

[Gordy M]

Just got off the phone with Vilven Tire and they said the largest 18" Kumho they are getting is the 285/30x18. He said he has not heard anything about a 305 or larger size yet. I went and ordered Hoosiers instead.

 

[Dave Schotz]

Ordering the Hoosiers now will atleast guarantee you tires too! The new Kumho isn't quite here yet anyway... So you made the right choice for now... but the 305 is a bit big for the 10.5 anyways... and a 285 actually fits the wheel very nicely... and Kumho has been 'conservative' on it's sizes before! But yes, Kumho will only have a 285/30/18 Rear, and then of course they have the 275/40/17 Front.

Peace,
Dave Schotz

My other favorite site, www.SCCAForums.com

 

[Jose Gonzalez]

I am using my stock Z06 wheels with my race tires and bought a set of reproduction chrome wheel for the street. As far as tires, we are out of luck. I bought four of the BFG's for the back do to the great price. I got 20 autocross runs,they did not stick and they were shot. I still have the other two that I plan to return. The Hoosiers have good stick but they are expensive and do not last. I have been running the Hoosier and will until the Kumho comes out. The biggest problem is that both the BFG and Hoosier come with only 3/32 of rubber. The old Kumho has 6/32. I just hope the new Kumho is good and come with all the rubber. I also agree that the 305 is to big for the 10.5 rim. I feel a 295 would be great but the 285 will work.

 

[Guest]

Rear- 315/35-17' on 17x11 GS wheels
Front - 275/40-17 on 17x91/2 GS wheels

Hoosier and Kumho

 

[tjea]

I have a set of Kinesis K20 wheels with Hoosier Dot Radials RR compound
Sizes
Frt 10x17 w/ 275/17
Rear 11x18 w/ 305/18

Purchased wheels from Mr Farmer. Mr Farmer was great to deal with. Kinesis makes a great product, but very slow.

 

[Day]

I just got a set of CCW 18x10.5 front and 17x12 rear. I had the BFG's put on because of the price while I get used to this size. John recommended this size because it was hard to get power out of the turns with 18" rims in the rear. I have 335/35/17 in rear and it hooks up nice out of a turn.

 

[DJWorm]

Running 17's in the rear effectively raises your gear ratio from 3.42 to 3.55!

 

[Jose Gonzalez]

The gear ratio change will vary with the size of the tire. I am pretty sure the 335/35-17 has a larger diameter than the 295/35-18 or the 305/30-18.

Jose Gonzalez

 

[Dave Schotz]

Yes, the 335 is definitely taller than the 305/30/18. And a 295/35/18. The 335, probably lowered your ratio from 3.42 to 3.33 or so.

The 17's are better in the back due to the increase in Sidewall, along with the footprint.

Nice Job! Also, I just wrote a detailed explanation of some testing I just completed with the new Kumho tires (which they have in the 335/35/17) But my testing was in closer to 'stock' Z-06 sizes.

Unfortunately the 285/30/18 is too small for our cars, but if you want to read about some of the improvements with the new tire, feel free to check out the link.

http://www.sccaforums.com/ubb/Forum15/HTML/000087.html

Peace,
Dave Schotz

 

[racingfast]

SO am I understanding some of you guys are ok with the 17x11" wheels in back? No computer sensor malfunctions? I run them with KUHMOS and after one event I have no problems.

 

[Dave Schotz]

You won't have any computer malfunction issues. I ran the 17X11's Kumho Rears earlier in the year. Just make sure your Traction control is of course turned off!

Nice Car & Color choice by the way! I have the same, SPDWY White, w/ Mod Red Interior.

Peace!

Dave Schotz

 

[racingfast]

DAVE--why do you say turn off the Trac control?? I ran my autocross in COMP DRIVING and except for blowing thru the stop box once as the ABS was pulsing, it was fine. Are you saying with it on I may have troubles?
And ... BTW: you have good taste too! Brian

 

[Silver Bullet]

In competition mode the TCS is off but the Active handling system is left on.
Once your skill hit's a certain level you need to use advanced techniques which would trigger the active handling to engage.
Especially on an autocross where the tires slip angle would need to exceed what the computer would most likely allow.
I found at several road courses I left in on out of curiousity and found it coming on more freguently than I thought. But it was truly when you pushed the car real hard.

 

[racingfast]

OK Silver Bullet. Then no damage can happen from the 17" wheels. I will try to run this sunday with it off. I didnt see where it came on in COMP last week, but I am just learning the car. Whatever happens, if it only gets better, I will be a happy camper!

 

[Dave Schotz]

You will be happier... the Competition mode, will do slight things like apply the brake to certain corners of the car. You are better off to learn the true characteristics, and how to react to them.

Enjoy,
Dave

 

[racingfast]

DAVE.... you mean so far in COMP mode I have been perhaps going SLOWER than the car can go cuz of the braking? I have an event this sun.. will run with it OFF and see what happens.. My old 90 I had to drive the car and react, this car I thought it would be better using the computer to help me. Thanks for your imput.. BRIAN