Hi Twin Plenum - your on my topic there with improving the P6 supension / ride handling compromise. But I do take issue with you saying the P6 design is very antiquated. In basic design it is arguably a match for many modern cars. Where it does depart is in steering design - not only is it worm and roller rather than rack, but it is set up to cope without power assistance whereas modern cars assume PA in the design and therefore have certain additional freedoms in the geometry. Having said that a manual steered 4 cyl car with a well set up steering box is surprisingly informative and accurate once you have loaded it up into the corner. It's just around the straight ahead they are unusual by modern tastes. Similarely the ride / handling compromise does not match modern convention in being biased much further towards ride than is normal today.
Worthwhile improvements can be obtained by simply by fiting an uprated front anti roll bar and decent dampers - AVO are probably the best currently available. Then you can play tunes with ride and front rear balance care of uprated springs. Opinion is that you can go to +50% stiffness before there is a noticeable deterioration in ride, personally I'd prefer a bit less than that.
Lowering is of course absolutely verboten for performance (OK if all you want is appearance!) as it reduces suspension travel and also brings the back wheels closer to the D post pinch point.
My criticism of the suspension design is that at the rear the de dion does a superb job of keping the wheels vertical to the tarmac, but does not do anything to counteract tyre roll as many multi link systems do. At the front there is excessive camber change in roll, particularely with the V8 which has much shorter lower wishbones than the 4 cylinder (thanks to a wider engine bay for the V8), that's why that front roll bar and dampers are so important. I have my own patent mod to give slightly increased front suspension negative camber with the intention of further (over revised roll bar and dampers) improving turn in and there is a mod in existence to give a tad of negative camber to the rear wheels. (In both cases the idea is to counter tyre roll and keep the tread parallel to the tarmac).
Another mod which improves the performance of the front suspension is the Rover Car Club of Australia originated front chassis leg/inner wing reinforcing kit. Originally devised to combat chassis leg cracking in power steered cars under Australian road conditions it also appears to eliminate flex in the bottom wishbone pick ups and therefore improves steering precision.
Chris
Worthwhile improvements can be obtained by simply by fiting an uprated front anti roll bar and decent dampers - AVO are probably the best currently available. Then you can play tunes with ride and front rear balance care of uprated springs. Opinion is that you can go to +50% stiffness before there is a noticeable deterioration in ride, personally I'd prefer a bit less than that.
Lowering is of course absolutely verboten for performance (OK if all you want is appearance!) as it reduces suspension travel and also brings the back wheels closer to the D post pinch point.
My criticism of the suspension design is that at the rear the de dion does a superb job of keping the wheels vertical to the tarmac, but does not do anything to counteract tyre roll as many multi link systems do. At the front there is excessive camber change in roll, particularely with the V8 which has much shorter lower wishbones than the 4 cylinder (thanks to a wider engine bay for the V8), that's why that front roll bar and dampers are so important. I have my own patent mod to give slightly increased front suspension negative camber with the intention of further (over revised roll bar and dampers) improving turn in and there is a mod in existence to give a tad of negative camber to the rear wheels. (In both cases the idea is to counter tyre roll and keep the tread parallel to the tarmac).
Another mod which improves the performance of the front suspension is the Rover Car Club of Australia originated front chassis leg/inner wing reinforcing kit. Originally devised to combat chassis leg cracking in power steered cars under Australian road conditions it also appears to eliminate flex in the bottom wishbone pick ups and therefore improves steering precision.
Chris
