Tyre induced Geometry tweaks

[MikeE]

Having thoroughly enjoyed myself on the Folembrey trackday this weekend I've decided I need to get myself some trackday wheels and tyres (hopefully before Lydden on the 28th).

 

My cars been running CR500s from new on 6*13 fronts and 8.5*13 rears (it's a SL not an R500 ☹️). Now whilst these tyres/wheels are fine on the road I'm getting way too much understeer on track (hardly suprising with such large back wheels and only 135bhp!).

 

So I want to change to either A032rs or ACB10s (6*13 front and back). Thing is I've been told you need to tweek the front camber and change the rear 'ears' in order to set the correct geometry for ACB10s. So for the time being this would sway me towards the A032Rs assuming that now tweeks are needed for these).

 

My question is, do I need these tweeks given that I'm running CR500s already (and I presume the factory setup the suspension for these from new)? Or do these use the same settings as the A032Rs?

 

Any advice greatfully recieved.

 

cheers,

Mike.

[MikeE]

what no one has any advice *confused* *confused* *confused*

[Peter Carmichael]

ACB10s generally need half the camber of a radial tyre. You can run them on radial settings but they will twitch around a lot and wear prematurely and unevenly in road use. It is best to match them with more appropriate settings.

 

The chances are that your understeer is not down the the tyre choice and is correctable anyway with a few minor setup changes. For a start, are you suffering from high speed understeer or low speed 🤔 Does the car just refuse to turn in. If you trail some braking into the corner does it just refuse to wing the nose in 🤔

[MikeE]

It's low to medium speed understeer.

 

Whilst I'm sure it is possible to adjust some of this understeer out surely it's better to do this once I've got a tyre more suited to trackdays and a rim width more suited to the characteristic of a 'low powered' Superlight?