psycho-mullet

So I took the Vette out for it's first track day at PIR last november and had a blast. I started the day with decent and even tread depth all around and by the end of the day the front tread was nearly gone and the rears looked the same as when I started in the morning. The tire wear was very even across the face of tire. I tried to keep the pressure at about 35psi.

I'm curious if this is due to my chassis setup or my crapy driving or if front tire wear is a fact of life I'm going to have to learn to live with? I would have expected the rear's to wear a bit more quickly though admitadly I was being a bit conservative my first time out in the vette (I'm used to a GTi) and I was in a lower level run group with limited passing.

1999 C5 FRC
TOE
Front - 1/8" total
Rear - 0"

CASTER
L/F - 5.8 degrees
R/F - 5.9 degrees

CAMBER
L/F - 2 degrees
R/F - 2 degrees
L/R - .9 degrees
R/R - .9 degrees

WEIGHT - 3518lb - w/ driver
L/F - 966lb
R/F - 834lb
L/R - 854lb
R/R - 863lb

Left 1820 - 51.7%
Rear 1717 - 48.8%
Cross 1688 - 48.0 %

TIRES - Pirelli PZero Asymerico
Front - 265/35 18
Rear - 305/30 19

I can't say I like these tires that much (poor traction I thought) and I think I'll be getting 315 18's all around in the future.

Thanks

mikahb

Could be some of both, and tire size could be an issue too. Most of my track experience is running 295/40's up front and 315/35's out back. With this combination, and driving aggressively, I found that I got about equal wear front-to-rear. A 265 up front is a lot less tire than the 305 out back, so all things equal I'd expect a little more tire wear in front anyway. Remember the fronts do almost all the braking too - and when you're learning, most people have a tendency to brake, turn, brake again, etc. Where you put wear on the rears is aggresively accelerating out of the turns, inducing a little power-on oversteer. Being as PIR has a lot of big sweeping turns that are pretty fast, I'm guessing you weren't hanging the tail out as you accelerated out of every turn.

That setup seems a little strange to me - 1/8" toe in front seems like a lot. With that much camber, I'd expect (depending on the goal of the setup) maybe 1/16" toe OUT, or zero toe. Also, it's pretty normal to run a little toe-in in the rear with that much camber. Anyway - depends on the goal like I said.

Put some fatter wheels/tires up front, use the brakes less, use the throttle more, and life will be good!

C66 Racing

When doing DEs in my relatively stock 02 Z06 on stock wheels/tires, I found that the inner edge of the front tires wore out much faster than the rears or the outside of the fronts with alignment settings similar to yours.

In general, the Corvette understeers so I don't think it is unreasonable to see more front tire wear.

You can even this up with power on oversteer.

VetteDrmr

a bit with both above. 265 section tires are a bit small to match up with the 305s, so I bet you're dealing with some understeer. IF you're pressing hard through the corners that'll aggravate the front tire wear. If so, then you could back off just a bit, they'll probably wear considerably easier.

HTH, and have a good one,
Mike

MNCrystalRed2011

You may want to try dropping your rear tire pressures a bit (start with a pound at a time). That should loosen you up a little.

psycho-mullet

Dropping pressures in the rear will make it understeer less? I thought less pressure gives a bit more traction at that end? Can you elaborate on that a bit?

So here's what I got:

Less Toe in front
More Toe in rear
Less camber
Less brake
More gas
Wider tires
Watch the pressures

Awesome info! Thanks guys

I was trying to be smooth, turn in once and hold it all the way through, no see-saw action and no braking mid corner, just find a good line, but I definatly wasn't hanging the tail out. Considering how even the wear is across the tire I think you guys are right, too much toe and too narrow of a tire, and I'm probably braking too much before corner entry.

I've got another track day lined up this weekend so I'm going to try and get these adjustments made before hand.

Thanks again guys I'll probably have more questions as I'm planning on getting alot more track time this year.

mikahb

Good luck man! Also consider this: as long as you are in your car, out on the track, you are doing the MOST important thing right by letting your car do what it's meant to do. Everything else is gravy.

whosurdaddy

Agree with comments above. Though I have noticed newer drivers make the mistake of working the steering wheel like a light switch, when its actually a rheostat. One must prepare the car for turn in so it has a fair chance of getting some grip on the way in. If you use a brutal turn-in vs a measured turn-in, you're likely to experience greater front tire wear as a result.