Road Racing Tire Sizes

[ZR1dogan]

A question for you ZR-1 Road Racers:

I'm going to buy some Hoozier R6's to go on 17x11 AMolds. Is it best to stay with the 315 width or would going to a 335 give better handling/grip in the turns? The 335's list the wheel range from 11 to 13 with 12 being the measured rim.

Thanks for your comments

Robin
94 Dark Red - Almost Stock
94 Admiral Blue - Not Stock

[Hib Halverson]

I would think it would be pretty hard to answer that question w/o knowing about your car's suspension, what kind of tracks you'll run and your skill level.

Offer the forum a little more info and maybe some road racers will take a whack at it.

[ZR1dogan]

Hib,
Good Point.
I was asking the question from a general 80/20 perspective (i.e. is a 335 R6 too wide – or sub optimal - for an 11" rim). However, I acknowledge that there may not be a general 80/20 answer unless some of the variability is tied down some. So here goes:

Suspension
2 Cars both with stock suspension and brakes – presently. My Go Fast desire is just like 95% on this forum. Once I get used to going pretty well with stock, then I want to go faster (that’s why I have a 385). I can see C6 brakes, coil overs and adjustable control arms on one or both of the cars as a possibility – but for now stock.

Tracks
Primarily for short Road Course tracks around Houston or at Texas World Speedway in College Station. All for fun. Right now I can’t see myself trailering out of state – but as stated above if it gets in my blood, I might expand that outlook.
Also I plan to use the rears as one of the pairs I take to the Texas Mile. My Hoozier Drag Radials have been outlawed at the Mile.

Skill Level
Rookie - Workaholic that is not getting any younger and finally decided to work less and have some fun with his cars at some road course tracks. I LOVED it the few times I went several years ago. I was pretty aggressive and did well against all the other novices, lapping some. But not in the same league as the experienced drivers - Yet.
Presently naïve/inexperienced enough to ask a general question on a complex subject.;)

As stated above - Thanks for any comments.

Robin
94 Dark Red - Almost Stock
94 Admiral Blue - Not Stock

[gbrtng]

Hi Robin:

Stick with the 315 - trust me, you would never be able to tell the difference between
the 315 and 335 because the contact patch ends up looking very similar. The key to
getting optimum handling is proper tire pressure and a decent wheel alignment.

[cward]

I agree with Glenn (gbrtng). I liked TWS with some of its longer straights. And as I am sure you know, coil-overs help tremendously. I raced with several different combinations of tires: 275 - 315, 315 - 315, 315 - 335, 285 -335. Probably liked the 315 - 315 combo about as good as anything for the road course. My Z was setup tight for open road racing so on the road course it helped loosen up the car to go to the 315 front. Plus pressure adjustments. I used 275 - 315 Hoozier R6's when I was open road racing. Road courses like TWS are fun but my main focus was ORR at very high speed. Of course, that was several years ago before I started losing my driving skills by getting too old. :)

[batchman]

To the original question, I ran 335s on 11" clone A-molds and they fit OK (with the right wheel offset), I do find the 12" I'm on now a slight improvement although I am now showing a minor rub. 315/335 works for my situation quite nicely.

To add some advice though I would suggest a less aggressive tire at your experience level, as something with a tread pattern (like Nitto 555R2) will announce it's loading audibly, break away much more progressively and be more "catchable" than a full on slick without the merciless "plow and howl" of a typical summer street tire. When I switched from aggressive street tires to R comps I found them heroic in grip, right up until they had none. In other words, spin at your own risk ;).

The other thing a full slick will do is offer enough grip to load your stock suspension to very unhappy geometries and prematurely cord some very expensive tires.

Please do note that most of my experience is with A6s, same construction different compound than R6; I have driven on R6s several times but only in autocross settings. Having come from a Z51 car (an 88) I gave up on the stock suspension pretty much right away.

Have fun,
- Jeff

[Ronstar]

You guys running 315 on front...ZR-1 offset or no? Clearance
Issues?

[cward]

I was using 11" wheels with proper offset in front for 315. Not ZR-1 rear offset which will not work, they touch hard. It is just about the offset of Grand Sport rears I think. And I used 12" wheels for 335. I liked r6 tires but as mentioned, they were great until they let loose and then it was interesting.