[ReEntryRacer]

So, I will sell my collection of GTA wheels. I have 3 sets, all serviceable, but raced for years, so not that pretty. No center caps or nuts or nut covers.
Located in British Columbia, Canada
$50/wheel plus shipping.

[charchri4]

Hey thanks for the info. I've pretty much decided on going from 17x9 to 18x10.5s all around.

I'm puzzled as to why, or how you can take out the negative camber and have it improve performance. I have never heard of anyone wanting anything but more negative camber. You are only 1/2 wider then the GTA wheels right? This is only my 2nd season so I am still very much in the learning curve. Could I trouble you to explain the advantage of reducing negative camber with wider wheels?

[ReEntryRacer]

Sure. With stock GTA wheels (8") and P255R/50-16s on the front, I had to run (left turning track) about 2* neg. camber on the Passenger wheel, and about 1.25* on the Driver side wheel. (Termperature readings across the tire surfaces are used to get inflation and cornering data) I did try 275/45s on the front 8" wheels, but that was not recommended for good reasons; I blew a Hoosier R6 tire to pieces from the stress. I also noticed that with my nose heavy car, if the front and rear tire contact patches were the same (ie 275) then the car was tail happy ((loose), probably mostly due to the huge bite on the front, and less bite from less weight on the rears. Reducing that contact patch (the 255s) did reduce my cornering grip on the fronts, but settled the car down and it became balanced and much easier to drive hard. But...I was not able to get a better grip with those stock wheels (8") on either end, so elected to go with the wider wheels (wagon wheels are plentiful and some 'vette drivers will send them to you just get to them out of their storage areas!).

I chose 18's knowing that the rubber selection was going to be getting better, rather than worse (16 inch tires are losing sizes across all manufacturers). Also, the huge addition of space allowed me to do any brake upgrade I wanted, so I went to 13" from 12" rotors.

After all this, I found that the 18" x 275/35 Hoosiers on the front were running very hot on the inner edges, rather than a normal gradient of temps I always look for. I attribute this to my large negative camber required for the much higher aspect ratio of the 255s. With much less sidewall rubber to flex, I needed less angle to the road. I don't have exact numbers yet on what works best, (too many rain events!) but I am down to .7* driverside and .5* passenger on my home track here in BC. I will be doing Seattle and Portland (fast RH turning track) if all goes well, and I should have more data on this so I know what I'm sure of. The handling and grip are better, in any case, and I did the fastest qual. time in the car's history on my first dry race, even with the camber set too high! I'm looking forward to sorting this all out.