What about tires ?

[roverman]

GT-1 car came with "McCreary's",23.5/11.0/15 ,slick with 10"tread. Thing is, it's bias ply(old-school). Shoudn't I go radial slick ? So far, no luck on comparable sizing. roverman.

[Bill Young]

Art, wheither you run bias ply or radial will really depend on your driving style and feel you like in the car. Of course size and compounds do enter into the selection as well. Changing to radials will also mean that some of the suspension settings will have to be adjusted as far as camber, caster, etc as the tires perform quite differently because of the difference in side wall ridgidity. Other racers will most likely to be happy to share some of the information with you up to a point, from there on it'll take track time and trial and error to tune in the car for what ever type tire you run.
Another factor is the wheel size and width you are allowed to run. For classes requiring wheels within an inch of original equipment bias ply "cantilever" tires are generally used as they offer much wider contact patches for a narrow rim width. Radials like to be mounted on rims nearly the same width as the tread.

[roverman]

Bill, Tire I listed is maximum size to fit.Only medium compound available(McCreary). Using 15x8" rims, front/back. I haven't found a comparable sized, racing radial. Getting enough accelleration traction, will be a challenge.Thanks,roverman.

[Moderator]

What are the currently competitive GT1 cars running? I imagine knowing that would be a good place to start.

[Bill Young]

Art, are you going road racing or auto cross? Will make a huge difference in compound selection. I checked as you have several of the tire suppliers and as you said, nothing comparable in a radial for that wheel width. Generally any 10" wide radial calls for a 10" wide rim as well. With the limitation on wheel width you may well be limited to a cantilever bias ply tire to get the width you want.
Have you checked out the threads on Phillip Leonard's RV8 racer? I don't remember right now what size tire he's running, but he's facing similar size problems I believe.

[roverman]

Curtis and clan, It would be dumb for me to hack the car for bigger tires.Phillip,weigh-in ? I don't like having, one brand and one compound. I believe the "IMSA" version of thre Group 44's ran larger tires ? I'm keeping this car as close to the original Huffaker build as possible,cubic inches, maybe not. Looks, definately.Thanks all, roverman.