Am considering the Kumho v700 rear in a 245/40/17 and front V710 215/40/16. Any idea on tire life and TCS issues. The front is 22.8 diameter compared to stock at 23.6. Would like to get 3000 miles with a few track days per year. These tires have a treadwear rating of 30 in the front and 50 in the rear. I would think that it would be a good setup for neutral handling with the more aggressive tire in the front. Ideas?
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Race tire life? Size??
- Thread starter Steve
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Why are you considering different model track tires for the front vs the rear? That's generally not advisable. For neutral handling, use the same tire, front and rear. You don't want to introduce an additional variable that is only going to confuse things.Steve said:
TCS should not be a problem with those sizes on your '93. The outer diameter of the front is 1.3 percent less than stock, and the rear 0.6 percent less, so the front-to-rear ratio of diameters is changing by less than 1 percent.
Are you planning to drive these tires on the street? Or only to and from the track? Most people only use track tires on the track (possibly also to and from the track, although these sizes should fit inside the car if you want to drive to the track on your street tires). In which case, you generally measure your treadlife based on track miles, not on street miles.Steve said:
I've found that one big factor that affects treadlife with track tires is how the tread wears. When you drive on the track, the outer shoulders of the tire tend to get rounded off (and even more so on the left tire for tracks that run clockwise i.e. more right turns, and on the right tire for tracks that run counterclockwise i.e. more left turns). I've driven with some track tires like the Yokohama A032R, where this shoulder can get rounded off without exposing any belts, so you can keep driving on the tires until the belts show in the middle of the tread. As a result, these tires last longer. I've also driven with some track tires like the Kumho Victoracer V700, where the belts go further out to the edge of the tread; as the shoulder gets rounded off, the belts start showing, and you have to dispose of the tire even though there may be tread depth along the rest of the width of the tread. Which explains why I get a whole lot more track miles on the A032R than on the Victoracer.
I have not used either of the tires you mention. I have used several different kinds of track tires on my '91 NSX, all in the stock '91-93 sizes. (They fit inside the car so I can drive to the track on my street tires, and you can pick up used sets of stock '91-93 wheels for next to nothing!) I find that I'm generally getting around 1700 track miles plus 500 street miles for Yokohama A032R tires on the NSX, both front and rear, with tires heat cycled but not shaved, from the time they're new until the belts start showing. I get maybe a couple hundred fewer track miles on Toyo RA-1 tires, also heat cycled but not shaved.
so the real question is, Ken, do you like the RA1 better or the A032?
RA-1.NSXDreamer2 said:
The reason for the mismatched tires are two. Firstly, they do not make the correct size in the v700 for the front. And secondly, I would think that the stickier front tire would make the car more neutral and oversteer less. The 215/45/16 is a rare find in any tire.
A stickier front tire will make a car oversteer more, not less. But again, you are adding another variable that will only complicate your handling, not straighten it out. For neutral handling, use the same tires front and rear, especially when using R compound tires.Steve said:
In the case of the Khumo's using the stickier tires in the front is not a good idea in that they will become very slippery due to the heat the tire will generate and the tire will go off real quick long before your track session ends and the rears are just getting into their prime stickiness. The reason for that is that the V710's were designed to heat up quickly for the autocrosser who doesn't worry about 20-30 long sessions on a track. The V700 are designed for the longer sessions and thus take longer to heat up. Once they do, they don't go off as quickly. This is what I've been told by those wonderful people at "Tire Rack". However Andrie would have the most experience with this combination.
Good luck.
Good luck.
