Colin, my information is that it was double wishbone front suspension, pivoting on fore-aft oriented steel tubes to allow for the longitudinal compliance necessary for good ride comfort, but with the tight tolerances laterally to keep good suspension geometry for good handling. Something of the philosophy of engineering embraced very, very much later in the FWD Lotus Elan and the McLaren F1. Wheelbase control isn't important for good dynamic steering geometry but precise control of track, camber and caster change is. Rover had this worked out on P6 and P7 prototypes. A google search for 'Rover P7' gives us
Rare Rovers - P7
Of note on this page are the descriptions of the P7 prototypes, including the notes for
P7A and very importantly the
P7/C.
The
P7/C Reg No: OXC831E having the P8 front and rear suspension and the V8.
"
P7A
Registration No: Not remembered
The front suspension of P6, designed to provide an engine bay wide enough for the possible fitment of gas turbine engine, had long been recognised as a severe constraint on road noise refinement and cornering performance through poor wheel camber control. By this time thought was being given to a P5 replacement known as P8 so this further batch of P7s was commenced. P7 was planned before the V8 engine decision was taken; thus it was built with a 6-cylinder engine. The major change was the incorporation of double-wishbone front suspension mounted on a subframe which was isolated from the body by 4 cylindrical interleaved rubber bushes disposed parallel to the vehicle longitudinal axis. Alteration of the position of the inner pivot height of the upper wishbone was possible, thus allowing various roll centre heights to be explored. During subsequent testing the optimum position was determined balancing camber control and steering kickback."
and
"
P7/C
Registration No: OXC831E
Front suspension and engine installation were as P7/B but the rear suspension was completely new representing the intended design for P8. It incorporated a fixed length de Dion tube, forward of the wheel centre line, pivoted on a complex rubber bearing mounted on the axle extension housing. Constant velocity plunging driveshafts were used and diagonal radius rods completed the location. Early assessments were very encouraging with major improvements in ride, handling and road noise reduction. The usual development programme of spring and damper optimisation, suspension bush rate selection and tyre selection occupied and educated our small team of engineers."
With one quote from this article, perhaps explaining why Jaguar were so keen to nobble the P8, even at such a late stage...
"As a postscript it is worth recording that the P7 work led to a P8 design which produced less road noise than a Jaguar XJ6."
Rover were very keen to improve on the ride refinement and transmission of road noise familiar to P6 drivers, with suspension loads and vibration being fed into the main bulkhead on our cars by the spring location. It appears that as typical in the days of old Rover, the engineers overachieved, so thorough was the job done.
So it seems the P8 was quicker, lighter, more economical, better handling, better riding and more refined than the already quite highly rated XJ6, long touted by the British press in Car, Autocar and Motor, as the best car in the world and better in it's ride/handling abilities than the German opposition from Mercedes Benz, let alone BMW's pretty but badly flawed E3 (with it's 'oh my god' oversteer in the wet semi-trailing arm IRS).
No wonder Lyons wanted the P8 dead.