Thanks all for replies.
AJI, wow! Looks like you've found the only "cheap" 17" tyre larger than 245. Of course the McLaren F1 and Jaguar XJ220 still have wide 17" tyres, but those are too expensive. On further research some of the Ultima GTR owners run those F40 tyres. The problem is that 335 was considered to be sufficient for 600+hp back in 1990, so for somebody running only 400-450hp today 335 seems excessive and unnecessary. On the other side, 245 seems too narrow.
Ted, yes, agreed that the details of the suspension design are extremely important. However, the suspension cannot be designed without choosing a tyre first! In fact, the tyre heavily influences several objectives of the suspension design, for example the camber and camber changes, bump steer etc. As far as I can tell the process goes something like this:
- Choose what type / format of car you want, how much power it will have and approximate weight.
- Select rear tyres wide enough to handle the power.
- Select front tyres sized in proportion to the front, depending on the estimated weight distribution.
- ... A few steps later, suspension design can begin.
Phil, very interesting. How much power does your Lotus have? How's the traction? Do you think it could run 400-450hp with sufficient traction?
On further consideration I'm severely tempted to drop down to 16". The reasoning being: Well, 17" was big enough for 500-600+hp back in the late 80s / early 90s, so surely 16" would be sufficient for 400-450hp with the rubber available today. The problem still remains: Surely 245 is too narrow.
Does anyone have any thoughts on this? What's the narrowest tyres used on a 450hp car? The narrowest I can find is a 275/30/R19 on the rear of a 2017 Holden Commodore SS (6L Chevy V8).