G32 Suspension


FRONT SUSPENSION

 

The front springs and dampers are inclined at a 45 degrees causing the rate to decrease when the spring is compressed, this has the effect of causing the car to roll at the front and jack up at the rear causing excessive roll under steer. The front suspension design, although not perfect, is just exaggerating a more fundamental problem at the rear of the car, 

 

The dampers are not positively located at the top of the chassis turrets, they can become "necked" by rubbing against the chassis locating hole. This problem was described by Mike Gerrard in Ginetta newsmag number 69. He reasoned that this wear pattern was caused by radial loads being fed into the top mounts. Modified top mounts (see photo) and GAZ Spherical bearing dampers overcome this problem.

 

ROLL CENTRES
The front roll centre is at ground level (parallel wishbones). The rear suspension is sourced from Ford Fiesta road car. Road cars have a high roll canters to reduce body roll when fitted with soft springs to give a nice smooth ride. Race and sports cars have a low roll centre to give a degree of body roll when fitted with stiff springs. So what you have with a G32 is a race car front suspension and road car rear suspension.

 

To give more balanced handling the G32 needs its rear roll canter lower. To achieve this move the inner track control arm mountings lower on the chassis. Weld a 1" strip of steel to the lower edge of the existing track control arm inner mountings, and drill new holes 1" below the existing holes. The tie bar chassis mounting can be left as standard, the extra anti squat does not adversely affect handling  This achieved the back end of the car has lots more feel, you can lean on the rear tyres with the confidence that the car will not jack up and snap into a violent spin.


ADDITIONAL MODS FOR AUTOCROSS

My autocross G32 has the inner track control arm mountings 2” lower than standard to give more poise when negotiating bumpy high speed corners. With this setup the tie bar chassis mountings will need to be moved to give a sensible amount of anti squat. The MacPherson Strut top mounts are too low limiting the amount of upward suspension travel. This is not too much of an issue on a road car but will become apparent if the car is lowered for motorsport. With this set-up the rear spring rate should be in the region of 170lb for the road, 225lb for autocross and 450lb for sprints.

The front suspension of my race G32 has been radically modified. The front dampers are positioned almost vertical to give more downward suspension travel and proportional damping. With the extra travel the front spring rate can be reduced to 200lb (350lb for sprints).

CAR & CAR CONVERSIONS magazine. June 1995.

‘The Ginetta G32 was a revelation. This is the sort of car you can get in and drive hard from the word go. Everything about it is user friendly and well set-up. The steering is pin-sharp, the gear change super quick and the mid-engined chassis well balanced with loads of grip. In short it installed total confidence to really push it.


Near vertical front dampers


Standard G32. Lots of roll under-steer!!!


Near vertical front dampers and rear roll centre 1" lower.
Lots of nice over-steer on 2nd gear corners but will spin out on faster 3rd gear corners.

Near vertical front dampers and rear roll centre 2" lower. Balanced on fast 3rd gear corners but will under-steer on slower 2nd gear corners. It needs lots of welly to get the back end out.