For racing only what do you look for other than size when selecting slicks? Compound? Stifness ? Etc. As I upgrade my suspension I want to be running the best selection for tires.I may need to change gearing to allow running a smaller daimeter tire to get a different stifness , compound etc. Can anyone give some selection parameters ? My current Hoosiers were selected because they were the tallest 10" tires I could find. They are compound D5 which are very soft.

Thanks.

I would probably leave the diameter and gearing alone unless you have another reason for changing that. The taller sidewall is a good thing IMO as well as the longer rollout/footprint.

I think compound selection comes down to the vehicle weight, how violent the launch is, and most importantly, the temperature of the track surface your running on. For hot greasy summer months you would likely want a harder compound and for colder track surfaces, a softer compound.

You sometimes also have an option of a standard or a stiff sidewall. Heavy cars can benefit from the stiff sidewall tires as it better supports the vehicles weight. You will also not break down the sidewall cords as quickly. I believe Goodyear has the widest variety of compounds to choose from.

Another option is a radial construction tire which will react similar to a stiff sidewall, but has less rolling resistance of a radial. Depending on the chassis setup, a radial can be great or if your chassis is marginal in it's setup, the tires could be inconsistent.

A friend just went 9.84 @ 133 mph in a 3560 lbs NSS '66/67 Fairlane on leaf spring suspension...haven't heard what his 60' was yet. He's pretty happy with the 10.5 x 30 Hoosier radial although he replaces his fairly often (sponsor provides tires).