Howdy,
On Fri, 26 Oct 2001, Jake Hodges wrote:
> For my birthday, a friend got me a set of very nice tires. That was three
> autocross events ago... Just 12-15 runs. I run 48-50 psi front and 38 rear
> in my Yokohama AVS Intermediates on a '95 Honda del Sol. My chalk marks
> don't scrub off of the sidewalls at all beyond where the tread blocks merge
> with the sidewalls.
>
> Questions:
>
> I know these tires are soft, but my front tires are almost totally rounded
> off on the outsides after just three events. What can I do to minimize
> this? Driving? Pressure? Voodoo hex?
What sorta alignment are you running? Can Hondas change front camber
legally in stock? Those pressures sound a little high, but the sidewal
rollover is the main thing to watch. You want them to rollover a bit, but
not too much. Show them to an experienced person at the next event maybe?
You're probably, like some other folks have said, overdriving the front of
the car. At least a couple things to watch for here. One is "slow in,
fast out" like other folks have said. Another that I've seen a lot of is
that when the front tires start to slide, you have to unwind the steering
to let them hook back up and grip again. The natural tendency is to keep
the wheel cranked over, scrubbing rubber off onto the pavement. As a
bonus, you'll be faster when you start unwinding the wheel as well! :-)
It doesn't matter where you are in the corner. If the car is pushing, you
have to unwind the wheel until it grips again, then feed in more steering,
etc.
> When do they wear too far? When are they no longer safe to use on the
> street? Or should I just not worry about it?
This is personal preference in large part. Certainly if the tire is
showing any cord or has any sorta indications of failure like sidewall
bulges or whatever, its time to replace them.
> Can the tires be turned around on the rims to present a new square edge on
> the outside without hurting anything?
I believe Intermediates are multi-directional and flippable. Look on the
tire sidewall. If there are no "outside" or directional markings, you're
good to flip them.
> If this really is the rate that I'm going to go through tires, should I just
> leave the only reasonably rounded rear tires on the back and nuke the hell
> out of the front ones, replacing them at a shorter interval? Or will I get
> more net tire life if I rotate them after every event?
Assuming they're the same size, I'd vote for rotating. That way the
fronts and rears die at the same rate, which shouldn't lead to as many
handling changes as you get tire wear. I think net tire life will be
similar for both approaches.
> Finally, people say they get a season of use out of race rubber on a
> light(ish) car like mine. Is this a function of some magical property of
> race tires, or are these other drivers on crack?
It depends on how much you run, how hard you drive, how well your car's
setup, how much you care about grip, etc. I've never even come close to
getting a full season of wear on a set of race tires (DOT or slicks), but
I tend to run a lot of events, I'm fairly aggressive, and I'm willing to
spend more money to have the best stick. Other folks do it differently.
That said, the type of tire wear you're describing after 12-15 events is
pretty darned excessive. Chances are pretty high that something is wrong.
Good luck!
Mark
(btw, just to make you feel a little better, I corded the insides of my
first set of race tires (R1's) in 10 runs. Something about having 3/4"
toe out... :-O Don't believe your buddy when he says he's pretty sure he
set the toe... :-)
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