Originally Posted by
Marc sierra
You are right in thinking it reduces chassis rolling. But that difference is really small as it is the track width versus the height of the centre of gravity, and the difference on the track width is not much compared to the total track width. But the negative handling is caused by the difference is scrub radius. The scrub radius is the distance between the centre of the tyre and the point where the tyre rotates when the
steering wheel is turned as is very important for the
steering feel. I don't know how much the normal scrub radius of the 4x4 Cosworth is, but on most cars it normally is something like 0.5 to 1 cm. Adding wheel spacers of 1 or 2 cm changes it a lot and doesn't help the handling.
BTW, I have 17x8 wheels on my 4x4 Cosworth with big brakes. The tyres are 215/40, but the front and rear arches indeed have been rolled.
Hi Marc, thank you very much for your detailed explanations on the technical point of view in terms of handling if the wheel sits further out. I think I get what you mean.
So can I understand that when upgrading bigger wheels, a setting that will not upset steering feel
OR handling of the car would be keeping the center turning point of the tyre/wheel as close to the original 15' wheel settings (or vertical to the hub point) as possible?
I have attached 2 calculations pictures below (one being sits further out 17 x 7.5J ET35, while the other sits further out and inner 17 x 8J ET40) and I wonder if the setting on the right
"theoretically" have most minimum, if not, no impact to steering feel or upsetting handling at all?
Thanks!
