Tire Wear Problem
04-20-2007, 12:21 AM
#1
Melting Slicks
Thread Starter
Tire Wear Problem
Need some ideas on what happened to my tires while running on VIR North. Car is an 02 Z06. Just added T1 sway bars with the T1 end links. They are adjusted with no preload.
Fresh alignment. Done on a new Hunter rack.
Front: Camber -2.0 ; Toe out 1/32nd per side total 1/16th ; Caster 7.0
Rear: Camber -1.3 ; Toe in 1/16th per side total 1/8th
Steer Ahead and Thrust Angle are almost dead on 0.
Tires are Nitto RII with about 4 events on them. Left front is slightly newer than Right front. But wear was almost even across the whole tire before I went out.
Temps were darn cold as anyone who was there would agree. This was the THSCC April 8/9 event. I've only done North once before.
Here is the link to a high res shot. Top tire is the right and bottom tire is the left. Notice that the right tire is worn hard from the inside to the middle.
Tires
So far I've come up with
Alignment changed and the toe on the front right is now off? (It's going in the shop early next week to verify).
Turn 7 is a hard right and steep uphill. Maybe I dragged the heck out of the tire?
For some reason the front bar is not adjusted right and doing something strange to the right side?
Other than that I've done Full, Grand East and South at VIR and this never happened to me before. I don't recall this kind of abuse the first time I did North on stock tires.
Fresh alignment. Done on a new Hunter rack.
Front: Camber -2.0 ; Toe out 1/32nd per side total 1/16th ; Caster 7.0
Rear: Camber -1.3 ; Toe in 1/16th per side total 1/8th
Steer Ahead and Thrust Angle are almost dead on 0.
Tires are Nitto RII with about 4 events on them. Left front is slightly newer than Right front. But wear was almost even across the whole tire before I went out.
Temps were darn cold as anyone who was there would agree. This was the THSCC April 8/9 event. I've only done North once before.
Here is the link to a high res shot. Top tire is the right and bottom tire is the left. Notice that the right tire is worn hard from the inside to the middle.
Tires
So far I've come up with
Alignment changed and the toe on the front right is now off? (It's going in the shop early next week to verify).
Turn 7 is a hard right and steep uphill. Maybe I dragged the heck out of the tire?
For some reason the front bar is not adjusted right and doing something strange to the right side?
Other than that I've done Full, Grand East and South at VIR and this never happened to me before. I don't recall this kind of abuse the first time I did North on stock tires.
04-20-2007, 10:43 AM
#2
If the alignment check is good, then the T1 bars most likely reduced your body roll to the point where either less camber is needed.
You can also lower the air pressure a cohple of pounds to shift some wear/contact to the outside of the tire.
You can also lower the air pressure a cohple of pounds to shift some wear/contact to the outside of the tire.
04-20-2007, 11:23 AM
#3
Race Director
The cold track temps and stiffer bars could have reduced grip to the point that you had too much camber in that corner, but that seems like a stretch. 2.0 isn't that much in my experience. You may have a bit too much toe out in the front, but I doubt that would have caused this.
I'd just rotate that one on the rim, and go even it out next event!
I'd just rotate that one on the rim, and go even it out next event!
04-20-2007, 01:32 PM
#4
Melting Slicks
Thread Starter
XPC5R - The T1 bars keep the front end almost dead flat. That is one of the things I noticed with them. It took some adjustment in my driving habits to get adapted to them. I wasn't sure if the front bar was so stiff that it is lifting the front wheel on some turns. I didn't bother to bleed off some air. I'll mark my tires next time and compare pressures and rollover on the tires. It was too damn cold to want to do much that weekend.
David - I just went from -1.5 to -2.0 camber and 0 toe to 1/32nd out per side on this alignment. Like you I wasn't expecting that camber change to cause me issues. Wasn't sure on the toe out. It seems so minimal. I can just run the tires on the opposite side of the car so I don't need to pay to have them dismounted/flipped/balanced. Even though they have tread grooves the RII will work just fine running in either direction on a dry track. I have the rears running opposite and can't tell the difference.
I went with more camber this time as I intend to run Hoosiers and everyone keeps telling me more camber is good. We can get almost -2.5 on the front. Since it is also a street car -2.0 is as far as I want to go. I might even go back to -1.5 if I have to pay to realign it. Guess I better get off my butt and start using a pyrometer and see what is going on.
David - I just went from -1.5 to -2.0 camber and 0 toe to 1/32nd out per side on this alignment. Like you I wasn't expecting that camber change to cause me issues. Wasn't sure on the toe out. It seems so minimal. I can just run the tires on the opposite side of the car so I don't need to pay to have them dismounted/flipped/balanced. Even though they have tread grooves the RII will work just fine running in either direction on a dry track. I have the rears running opposite and can't tell the difference.
I went with more camber this time as I intend to run Hoosiers and everyone keeps telling me more camber is good. We can get almost -2.5 on the front. Since it is also a street car -2.0 is as far as I want to go. I might even go back to -1.5 if I have to pay to realign it. Guess I better get off my butt and start using a pyrometer and see what is going on.