How "stable" is your car on the open road???

[stephen low]

Les

My fellow indicated that use of some rose joint movement ok for the rear, that's why they have bushes and rubbers, but there is a limit to what can be achieved.

In my case he is of the opinion that 1 - 2 turns of my LH rose joint is all that is needed to get toe in so both rear tyres are at about similar angles. This overcomes any later dabbling with the rear axle, given the out of line mounting hole issues for RMC and G Force cars.


Interesting to see you quote positive camber though.

Cheers

[Rebel1]

Originally Posted by stephen low

Les

My fellow indicated that use of some rose joint movement ok for the rear, that's why they have bushes and rubbers, but there is a limit to what can be achieved.

In my case he is of the opinion that 1 - 2 turns of my LH rose joint is all that is needed to get toe in so both rear tyres are at about similar angles. This overcomes any later dabbling with the rear axle, given the out of line mounting hole issues for RMC and G Force cars.


Interesting to see you quote positive camber though.

Cheers

Nope, not in favor of any "pulling" to achieve your geometry. There are enough stresses both fore and aft for the rubber bush to deal with as it is. Using it to pull the toe will only cause wear of the bush and then you are back to square one.

The geometry can be perfectly set using the shims and that leaves the trailing arm to deal with it's own problems. In the case of the RMC it runs straight forward so will pull on squat and rebound anyways.

The positive camber was just a starting point and depends on your top mounting point. Static positive camber in some cases can quickly turn negative with very minor body roll.

[NASSTY]

Originally Posted by Rebel1

Nope, not in favor of any "pulling" to achieve your geometry. There are enough stresses both fore and aft for the rubber bush to deal with as it is. Using it to pull the toe will only cause wear of the bush and then you are back to square one.

The geometry can be perfectly set using the shims and that leaves the trailing arm to deal with it's own problems. In the case of the RMC it runs straight forward so will pull on squat and rebound anyways.

The positive camber was just a starting point and depends on your top mounting point. Static positive camber in some cases can quickly turn negative with very minor body roll.

The issue of trailing arms of the jag rear end in a cobra is not new ground. The original jag diff is in a sub frame that is completely rubber mounted. If there were no trailing arms then there would be very little to stop the diff sub assembly from rotating forwards and backwards on its rubber mounts. Any binding caused by the training arms not having the same geometry as the lower arms is offset by the sub assembly's rubber mounts as well as the bushes on the trailing arms.

Conversely in a cobra where the diff is solidly mounted to the chassis, there is no additional play as there are no rubber mounts. The roller bearings in the lower control arms have far less play than the rubber bushes in the trailing arms which effectively make the trailing arms redundant, in my opinion.

Perhaps you may also place too much lateral preload on the roller bearing in the lower control arms if pulled in.