What width tyres?

[BB-Q]

I'm getting near to the point where I need to decide what wheel tyre combo is going to be fitted to my car so I can determine the width of the chassis rails and the rear axle.

I was hoping to go to 10" rears, but road tyres seem to be limited to drag radials in those kinda sizes, i.e. 325/50x15. Given my nonexistent budget I thought about going to 275/60x15 on 8" rims instead. Whilst not ideal in appearance the tyres are readily available and reasonably priced.

Given that I'd happily buy slicks for track use (expensive I know, but they'll get very limited use) and that my maximum diameter is 28", would say, 28/10.5x15 slicks be enough for around 550hp of four cylinder turbo motor?

I thought about dragradials on the road given that I'll do very low road miles, but the thought of wrecking one with a puncture scares me!

Could really do with some advice here.

[leecb05]

you need to decied what size tyre you are going to use cos if you set your gearing up for your road tyres then put 28" tall tyres on you are going to bog the motor down i would stick to one size tyre like a drag radial and gear it to them and not bother putting the smaller street wheel tyre combo on
i used to change from 32" to 33" tyres on my old slingshot and it was like two different cars et wise

[BB-Q]

Those tyres I mentioned up there are all 28" tall.

This is the area I need advice on. The gearbox will be a TVR T5 (2.95:1 1st gear) and the axle currently has a 3.27:1 diff in it.