c345vette

Hi All

I have a Question pertaining to tire feathering.

It seams that just the outer shoulders of each of the 4 tires are
" feathering back " a bit.
it is equal on 3 tires and a lot more wear on the drivers front (LF)
(still decent of tread in middle)

I am wondering what is the cause and correction.

CAR: C5 2004 Z06 Stock w/ 25k miles

TIRE: GOODYEAR EAGLE F1 SUPERCAR

AGE OF TIRE: 3 Years old (I checked date codes) garage kept car with 5,000 miles on tires

Tire Size: Factory Sizing 275-17 / 295-18

BRAKE PADS : STOCK Z06 GM

6 track days on tires 4 days vir, 2 days summit point

alignment was preformed by reputable shop with drivers seat weighted to simulate me sitting in car

FRONT

ALIGNMENT: LEFT RIGHT

CAMBER : -1.30 -1.30

CASTER : 7.35 6.9O

TOE: -0.01 -0.01

FRONT TOTAL TOE -0.02
STEER AHEAD 0.01

REAR

ALIGNMENT: LEFT RIGHT

CAMBER -1.05 -1.00

TOE 0.06 0.06

THRUST ANGLE 0.00




any thoughts are appreciated
.
.

brkntrxn

Sounds like normal wear for your setup. The outside edges are showing more wear because of the limited amount of camber you have. The left front is showing more wear due to running in a clockwise direction.

Three suggestions:

1) Dial in more camber. If this is a dual purpose car, then you are going to have to live with increased wear from tracking while maintaining street manners.

2) Rotate your tires from side to side after each day of tracking to even out the wear. And don't worry about the direction of the tread as long as there is no water on track.

3) Get different tires. F1s are junk in my opinion. I don't even like them for street use, but that is my opinion.

apex26

My 03 z06 has the same problem, even though the car has about another degree of negative on the front (maximum on stock bolts) and -1 rear. The more you read about it, you find out these cars don't hold an alignment very well with the stock bolts. So, I got the Pfadt alignment kit and will dial in even more negative before another set of new tires. If you're on stock brakes, you are no doubt getting faster and will need more camber and brakes soon. So, this is when it starts getting really fun--but also a tad more expensive.

c345vette

Thank You
3) which dual purpose tire did you prefer.
keep in mind I will drive a long distance to and from the track

c345vette

thank you also

Question: with the Pfadt alignment kit and dialing in even more negative before the next set of tires

will that still be ok for the street and be a happy medium for both purposes or more of a track setting?

apex26

The negative alignment has little effect on the street, other than being slightly more twitchy on bumpy roads. BUT, It will stop the premature disposal of expensive tires with 50% tread left. (The Pfadt allows for quick change back and forth for street and track settings) The tires that will be coming off are Michelin PS2's, which were awesome and wear like iron, and I might go with Michelin Supersports, which are rated higher in all regards. (I've got dedicated track wheels/Hoosiers also) Like you, these street tires need to perform in rain, street and track. Sounds like your tires are headed for the same fate as my Michelins--solve the issue now and save $ in the long run. You'll also appreciate the extra camber at the track.

brkntrxn

As someone else said, Michelins are good. For a 200ish treadwear tire, you can't go wrong with a Rival. The NT05 used to get good reviews, I am not sure how it stacks up nowadays.

As for a lot of camber (and any aggressive toe) on the street, your car will be twitch and will "tramline" on uneven pavement. Maybe not a big deal, but you WILL spill your coffee while talking on the cell phone. A lot of negative camber and a lot of street miles will also wear out the INSIDE of the tire, which is the opposite of what you are trying to prevent on the track (outside wear). Another consideration is a lot of negative camber will take away from your straight-line braking performance because you have less rubber on the ground. All things to consider on a dual purpose car.

twistedwankel

I autocross my C5 Z51 vert exclusively so got the most negative camber I could -1.8*F -1.5*R with 1/8" toe out in front and 1/16" toe in in rear. Car handles extremely well and tracks straight with Michelin SS on stock wheels 245's and 275's.

After one FL racing year 3000 miles, 24 events with about 150 runs including some co-driven events I'm on the wear bars but melted/peeled a 3"x1/2" spot on right front outer tread block after 9 long fast runs on concrete. The first 4/32" wore well like 2000 miles. The last 4/32" went faster than a one armed paper hanger drinking a latte. BUT they stuck like crazy all the way to the end. Different compound? These tires are great in the wet also.

Great tires on highway or racing. Proves to me the 300 tires don't last any longer than the brand name 200 tires or the old 140 Toyo's for that matter. One cannot flip the Michelins on the rim and put them on the other side like other tires due to the three different compounds and tread design involved.

They are just about as expensive as any number of 200 tires so that makes the 255 and 275 Hankook RS-3 ver2 @ $800 look inviting. I know they will heat cycle out long before they ever wear out from previous experience. Living in Fl they like this heat. Factory fit leaves little choice. Bridgestone RE-11's for $900 or take a chance with Toyo T-1 Sports for $600 for a 240 rated tire? I might do that as they are available locally and have a 45 day/500 mile satisfaction return policy supposedly. There's no money in this sport other than what you save.

Hope this helps. Michelin does offer a $70 rebate at the moment.

Gordy M

While I mainly autocross, I run 1.8 front and 1.0 rear camber, 0 toe in front--change at the event if the course is very technical to 1/32 each side tow out. Caster is about 6.5 each side. 2550 miles last year, 216 autocross runs and 6 Solo 1 runs, Bridgestone RE71R tires and they handle excellent. With 0 Toe very little twitching on the highway. Tires handles remarkably well in both warm and cooler temps, in a 49-51 degree day in October, my last event of the year, I was beat by only two Corvettes on Hoosiers. Ended with 5/64th tire left across the board, and flipped the tires twice. Since I ran 275/35/18 square on 9.5F/10.5R, it was easier to even out tire wear.

Also, every three years I replace all the camber bolts because I feel they must be stretched. Before I started replacing them regularly, I could occasionally get alignment changes in camber--ended with excessive feathering.