Suspension preparation for classic rallying

[Mudhen]

Cooperman said:

The 'as original' cones as sold by Mini Spares are really OK, although they do offer a 'red' cone which should work well, although I've not used them.
Best to raise the car by around 1 cm from standard then it is not necessary to have the dampers too stiff and the suspension can work better.

Thanks Cooperman.

Are those Spax shocks rebuildable? Assume you go through some during a season...do you also go through rubber cones?

(my class would allow me to use coils, that's why I'm curious about the longevity of the cones - just not sure if I should use them or not (which is probably outside the scope of this thread))

[Cooperman]

You really do not want coil springs for rallying. The rubber cone spring is a true 'rising rate spring' with the rate increasing as the spring is deflected. This is ideal for rallying. With a coil spring it would be necessary to have a huge rubber bump stop to prevent coil-binding, so there would be no advantage. Coil springs are good for racing as a high initial rate can be used, but for rallying a lower initial rate is necessary.

The rubber cone springs last a very long time, years and many, many rallies in fact, so long as the original quality/specification ones are used.

These days SPAX are reputed to be not as good as they used to be and GAZ have a better reputation. GAZ will rebuild them when they finally wear out, or you simply buy new ones.

[FWDRacer]

Spax and GAZ are absolute garbage- have experience (not positive) with both. Best units are Koni, not adjustable on the car though. Best compromise is the AVO units (based in Northampton), fully rebuildable steel or alloy bodied. These are the way to go.

[Cooperman]

Koni are good for track use, but for rallying they have a poor reputation. I think this is because the KONIs work on the 'softer on bump and stiffer on rebound' principle. This is fine on tracks, but for rallying the one thing you don't want is for the suspension to go down easily and come back up slowly. All that happens is that the suspension hits another bump before the car is back to normal ride height and it goes down even lower, then lower still until it hits the bump stops, then it won't steer. It is also difficult to just 'knock them up a click' after a stage if the damping feels a bit soft for the surface, or knock them back a click for the next gravel stage after a tarmac one.
I have used both SPAX & GAZ for fairly serious rallying and both are OK, although it is necessary to change them, maybe once every year.