High Speed Instability
Originally Posted by trinis2001,Dec 6 2005, 08:01 PM
Thanks, for the responses.
I never did get a chance to try that speed on my S02s which are brand new, but now reserved for auto-crossing. These RE050 tyres had about 3 months of usage before I got. I had the car aligned just recently, and they did leave a little castor imbalance, say around 5.x on the left and 6.x on the right. But the wobble seems to come from the rear. I thought it may be pressure (currently set at 30.5 F, 31 R cold psi), so I will try to up it to about 33psi and see next time I find that piece of road.
Cheers.
BillyB
I never did get a chance to try that speed on my S02s which are brand new, but now reserved for auto-crossing. These RE050 tyres had about 3 months of usage before I got. I had the car aligned just recently, and they did leave a little castor imbalance, say around 5.x on the left and 6.x on the right. But the wobble seems to come from the rear. I thought it may be pressure (currently set at 30.5 F, 31 R cold psi), so I will try to up it to about 33psi and see next time I find that piece of road.
Cheers.
BillyB
I suspect the problem is with the rear geomerty/RWS effect.
Ideally, the car should be set up as equal & opposite as possible. Small differences make a big effect.
I think in this bad weather the s03s are a godsend, my car feels alot more stable at high speed on s03s than s02s.
I had 4 wheel lazer alignment the other day and they didnt get it exact on each side for some reason however they said it was within the tolerances.
I had 4 wheel lazer alignment the other day and they didnt get it exact on each side for some reason however they said it was within the tolerances.
Originally Posted by Nick Graves,Dec 7 2005, 02:29 AM
Castor imbalance will tend to cause wandering or chasing the camber, as well as asymmetric reaction to bumps. But that is a front-end effect.
I suspect the problem is with the rear geomerty/RWS effect.
Ideally, the car should be set up as equal & opposite as possible. Small differences make a big effect.
I suspect the problem is with the rear geomerty/RWS effect.
Ideally, the car should be set up as equal & opposite as possible. Small differences make a big effect.
The highway was gently undulating and relatively new so it is very smooth with regard to the surface. The feeling I got was the same when i once had some soft-walled, high profile Avon tyres on my suspension tuned (read as hard as hell) civic. there is this definite feel of swaying, if ever so gently, when going in anything other than a dead straight line. Any corrections in steering makes the back feel like it want's to wag - not because of loss of traction, but more like rolling over on the sidewalls. It is all so subtle though - and this why I now say it does not inpsire me to try that too often.
Originally Posted by Nick Graves,Dec 8 2005, 02:29 AM

These cars have passive RWS.
If you modify the suspension wantonly, that's what happens!
I find this hard to accept.


