If I were to go for, say, the Suplex replacement what difference in steering would I expect to notice?
Ian, our cars are pretty much the same era, so I would expect your experience would be pretty similar to mine. If your car is prone to suffering the front-end shakes, then I would expect the Suplex conversion should pretty much eliminate it, but you'll still need to retain the damper blades. I wouldn't expect it to massively lighten the steering, especially if you are running 185 section tyres or larger.
In July I did the Suplex conversion on a 2005 PLUS 4, retaining the damper plate, but installing above it the supplied ball race. The steering is lighter and the ride on all the roads more comfortable. But the steering was not the major problem. In my case it is a real improvement.
By cutting the rebound spring, your shorten the travel where the rebound spring is compressed, but in the same time you increase also its stiffness and its seat is not good, compression force is not in the axle of the spring. In this case, the best way is to find a shorter spring with the same stiffness.
The stiffness of the rebound spring and the upper spring have to be compliant. The Suplex rebound spring is 2.5 times more stiff than the original one, but with any problem. The Suplex travel has roughly 2 times more travel on small bumpy section which solved my main concern.
