Mopar Muscle Association UK

Given that you don't have to worry about what will fit within the bodywork, suspension etc. (i.e. you can fit whatever size you like) what governs the decision on the ideal width and diameter of rear tyres for drag racing?

I imagine diameter may be dependant on gearing/rpm and the width on torque/power? Or is it just a case of bigger is better?

TyreFryer wrote:Given that you don't have to worry about what will fit within the bodywork, suspension etc. (i.e. you can fit whatever size you like) what governs the decision on the ideal width and diameter of rear tyres for drag racing?

I imagine diameter may be dependant on gearing/rpm and the width on torque/power? Or is it just a case of bigger is better?

Most of the times, the size of tyre/rim is dependant on what class you run in.
eg Prom mod can run 16" x 16" , Super mod restricted to 15" x 15"

By changing/playing with Converter, Axle ratio & Tyre & Rim diameter, you can also tune to suit type of motor used (High revver, high torque, etc) also adjust to suit suspension/car set up. ie heavy hit of the line, higher top speed with larger diameter wheels, etc, etc.

As for the width, the more surface area you have the easier it should be to gain traction, assuming suspension is working correctly and you have enough motor to turn the tyres.

Then again if you have ever seen the 10.5" tyre class, all of this seems to go out the window, those boys are awesome. Some look quite hairy with the amount the move around.

All good info.

Only go as wide as you need.

Otherwise you are increasing the rolling resistance for no reason. And big slicks have a lot of rolling resistance as you will know if you have pushed a car up the fire-up lane. In fact it is much worse on the track as the track is so sticky it is grabbing the tyres.