Tyre scrub issues :(

[Pullstarter]

Hey Guys,
Just put some 16mm spacers on the rear of my VR6. Have folded the guards as much as is possible but still getting very slight tyre scrub. I was thinking of dialing in a couple of extra degrees of negative camber, do you think this will help much or is it a bad idea tyre wear wise?

[gldgti]

it'll help - a bit of trigonometry - wheel radius ~ Rmm, stock camber on rear is c1 (in degrees)... say you go to c2 deg neg, then by a bit of simple trigonometry and rearranging equations, we have:

C = R x [sin(c2) - sin(c1)]

where:
C = new amount of clearance (in horizontal direction);
R = wheel radius;
c2 = new camber setting;
c1 = old camber setting;

so if your wheel radius (inc tyre) is 295mm, and you start with say 1 degree camber, and you increase to 2.5 degrees, you will get an extra 7.7mm clearance at the corner of your tyre, so long as the camber change rotates about the centre of the hub. NOTE that this is extra clearance ontop of what you already had (or didnt have, if its rubbing) so if its really fouling by heaps it might still rub.

but it'll probably change the high speed hard cornering handling of the car a fair bit, and would certainly wear the insides of wider tyres a bit more.

[Pullstarter]

Thanks for that awesome write up! How exactly will it effect the high speed cornering? More or less stable?

[gldgti]

Thanks for that awesome write up! How exactly will it effect the high speed cornering? More or less stable?

hard to say - in theory, more neg tends to give you more grip on the limit - but on the golf, the rear always tends to lift /throw weight forwards when your going fast (lift rear wheel). i don't think 2.5 deg would be too much on the rear for a mk3 (especially if it was pretty low (read nice and square, NO rake) ) but its all a matter of experimentation.

having the tyre square to the road is not always going to have hte most grip - it depends on how much force is going thorugh the tyre as well.... even a tyre thats on the OUTSIDE edge and rolling under is gripping - might not be ideal in the dry, say, but it could be better in the wet... its hard to say.

anyways, important thing is just to be careful if you've mad a change like that... make sure you know what the car wants to do.

[Pullstarter]

Thanks for your help much appreciated! It's about 50-60mm lowered and dead square with 28mm rear sway bar. I didn't think 2.5deg would make a huge difference in handling but hopefully enough to stop the scrub as it is only very slight scrub when hitting dips in the road etc. Thanks again