7 replies to this topic

[Hump3]

My 1990 RSP cooper had Spax coilovers when i bought it.

Although the ride height was level upon closer inspection one of the spring platforms was adjusted about an inch higher up!
this meant that this spring was becoming coil bound over bigger bumps with a nasty bump!

I removed the springs which were apparently 225lb/6inch and found that one was a little shorter.

Assuming the springs to be at falt i have replaced them with 2 new 190lb/7inch springs so that i can keep the coils further apart and use the upper mounting holes in the mounts. this wold mean the coils are less likely to become coil bound over bumps (also i felt the front was too hard for me with 225lb springs)

Anyhow it still wont sit level with the spring platforms level, to get it level i have to adjust the drivers side platform up signifigantly, and it look more like its just preloading the spring more than raising the car up!

i dont understand whats going on!!

i know the spax coilovers use krypton gas, my question is what kind of pressure is it at and would it provide and additional spring rate to the whole unit? (this was the case on my spax shocks on over cars.

if so do you think a shock that has lost all of its gas would cause the problems im having?

[Ethel]

Are the mounting points at the same height?

It's weight that compresses the spring so if one side is heavier than the other it will compress the spring more meaning you need to wind the seat higher to get a level car. The diagonally opposite wheel also has an effect as the car will pivot on which ever diagonal is nearer the road - a bit like a wonky coffee table.

[Hump3]

yep all the mounting points are the same height, will check the rear level later!

[Hump3]

Oh and i dont think the car weighs that much more on 1 side!

[Jammy]

Thats the whole point of setting up corner weights. You adjust each corners spring platform so that the car sits level.

Readie.

[Hump3]

i understand cornerweighting but cant understand why the diffrence between sides would be so great

[Ethel]

Returning to my wonky coffee table example...

If, say, the left front and right rear were set with a high ride height the other 2 corner springs would push the wheels down to touch the floor even though they would carry less weight. The front end springs are stronger (allowing for suspension geometry) so if the car was nearly balanced on LF to RR diagonal the right front spring would push up its corner more than the left rear.

The heavier bits of the power plant are on the driver's side - flywheel, gearbox internals... and of course there's usually a heavy nut attached to the steering wheel.

Sit the rear end on a centrally placed axle stand to take the rear springs out of the equation.

Edited by Ethel, 20 March 2008 - 02:55 PM.

[mini_turbo_pete]

I had the same with my old coilovers, the drivers side platform was always higher and if you jacked the front up on the drivers side front tie bar mounbt the car would always go up level and if you jacked it on the passenger side tie bar it would be unlevel.