StressedDave

I've done the preliminary testing at Millbrook on the unmodified car and the measurements of the linkages so I can work out what the rates should be. Then it'll be a case of getting the prototypes units valved up for testing.

And at least I can't make it any worse...

Doing the same for a Mk 3...

Not according to the kinematics models of the suspension I have. Toe out on turns is a max of 1 degree at 30 degrees of steer, even with 7 degrees of caster. I haven't got the steering arms positioned accurately enough to see what that's doing with bump steer, but any increase at the outlying values is probably immaterial given the significant increase in spring rates over stock. Anyway, back to the next design...

I think the mounts are a red herring - it's more likely to be a lower ride height at the rear canting the front adjusters clockwise giving more caster. The position of the spring within the coilover should make no difference to caster - that's purely a function of the two suspension arms and the upright pickup positions. Anyway, I don't think there's any such thing as too much caster, especially on power steered cars.

Blimey Dave, i've just realizsed who you are!!! Yes i agree this didn't make sense as "lift-off-oversteer".... It had me puzzled since the calibration was neutral but with rapid migration at yaw. One reason for this is the huge castor gains on the Puredrive suspension, i've done me math and i think it must be due to the top mounts? On this car i couldn't get the castor under 7 degrees ..... I think you will agree this is mighty high for a 5, ever more so since the steering arm is already out of radii with the radii of the lower arm. Maybe some spacers could be included in the kits if the car will not allow reduction of the castor naturally? I'm not sure that computes... the top mounts are standard Mk II mounts AFAIK (Oi Phil...) so there should be no reason why there'd be a limitation in the amount of caster you can get out of the alignment. I'm always happy to hear an explanation though...

Phil sent him to me as I did the initial design and development and the owner only lives around the corner. I'm not convinced it was true lift-off oversteer, more a function of reduced understeer as part of the design and the slow transition at the rear so a quick steering input could giv elots of response at the front but less at the rear.

Just finished twiddling the suspension on that car... aside from the newness of the tyres affecting cornering stiffnesses, the rear dampers needed a different setting. Before adjustment there was a distinct disparity in response times from front and rear. After...