Elite Veteran
Posts: 925
Location: Thinking of vvc'ing my Roadster Brabus :-) | MGF/TF lower suspension arms give more caster than GTI/metro/100 arms, so the hub steering arms are tilted down more, this effects
bump-steer, so the track-rod end ball joints have different ball-centres to compensate, also couple this with different ride heights
for the MGF/TF and GTi/Metro/100, which positions the track rod angle differently to the suspension arc with the varying models,
When I was at MGRover, I was in the same department as the guys who developed the Metro MGF and TF, I asked about the best bump-steer
figures for my Metro GTi as I had set it up for zero bump-steer, I was told that the best setup was to give 5min toe out on bump for each
wheel, this would give better 'feel' through high speed cornering, It did!,
There was a bulletin out for MGF 'Throttle Steer' (like torque steer) problem, it goes on to say, after tyre checks, suspension/ride
height/tracking checks etc, you then check bump-steer, if one wheel has an excessive amount or not enough, then you either space the
steering arm up (by a mm or 2), or fit a different track rod ball joint (with a different part number), which effectivly lowers the
steering arm to correct the bump-steer.
When I set my GTIVVC trackday car up with 8deg caster (yep 8deg with fwd!!), I had to space the steering arms up by 8mm to get the
correct bump-steer, I now have it set with 4 deg with the 20vt engine as the steering effort was getting to be a pain at low speeds.
|