Rear upper wishbone clearance

[theancientone]

Hi.....we had our Exocet 150 out on track (at Croft) for the first time yesterday. A great time was had by all, and the car survived!
We experienced some oversteer when powering out of bends, and whilst this might be over exuberance by the driver I'd like to see if any adjustments can be made to minimise this oversteer.
The first thing I notice when having a look at the car today is that there is at best 20mm clearance between the chassis frame and the rear top wishbones. With BC Racing coilovers and 6kg (~ 335lb) springs is it likely that suspension travel is being limited by this 20mm clearance under very hard cornering? Or unlikely?
If the frame were hitting the wishbones and thereby restricting suspension travel is it possible that this would contribute to the back end breaking loose?
The engine is a Mk2.5 1.8 with MP62 supercharger etc.
Very many thanks for any help.
Stephen.

[h20boynz]

Sept 18, 2016 13:40:08 GMT theancientone said:

Hi.....we had our Exocet 150 out on track (at Croft) for the first time yesterday. A great time was had by all, and the car survived!
We experienced some oversteer when powering out of bends, and whilst this might be over exuberance by the driver I'd like to see if any adjustments can be made to minimise this oversteer.
The first thing I notice when having a look at the car today is that there is at best 20mm clearance between the chassis frame and the rear top wishbones. With BC Racing coilovers and 6kg (~ 335lb) springs is it likely that suspension travel is being limited by this 20mm clearance under very hard cornering? Or unlikely?
If the frame were hitting the wishbones and thereby restricting suspension travel is it possible that this would contribute to the back end breaking loose?
The engine is a Mk2.5 1.8 with MP62 supercharger etc.
Very many thanks for any help.
Stephen.

Is there marking on the wishbone or frame rail? If it was hitting I'd imagine there would be a noise, clunk or at least impact marks to signal it?

[gbob]

One of the things that makes an MX5 tail happy is having the car too stiff at the rear. I'd assume the same with an exocet.
Try softening up your coilovers on the rear to see if that makes a difference.

[Stiggy]

the bump stop needs to be the shock absorber rubber seat not the chassis rail. It sounds like you need to raise the suspension or modify the chassis rail with a 10 lb lump hammer (don't quote me on that!).
You may also have 30psi in your tyres, try 20. Are your tyres wider than 195? These light cars may float around with fat rubber or incorrectly adjusted tracking/camber. The other cause can be a lack of burgers, so if you are under 75kg you had better get fatter for Christmas.
With a 75kg driver (no passenger) the front to back weight distribution is 50-50

[theancientone]

Thanks Stuart....what is the 'design' height of the Exocet floor from the ground please?