Rear suspension update

[Ian Mould]

Just a quick update on my suspension upgrade. The rear is all back together after a fight with the poly bushes. The 200lb shortened springs will come loose if you jack the car up - it's a shame the upgrade kit doesn't come with dampers about an inch shorter which would hold it all together. Not too worried about that as its all usually in compression but could be a problem if they lift the car by the jacking points for the MOT. Anybody had any problem with this?

 

There is no noticible difference in ride height with the shorter 200lb springs over the knackered originals.

 

And finally, to pass on a cock up I made! I took off all the suspension bits and then the exhaust so I could touch up the paint underneath. Painted the axle, swinging arms et al, put the new poly bushes in. Then I put the suspension back, torqued up all the bolts. Picked up the exhaust and - b******r! In my mind I suppose I was thinking Kwikfit don't need to take the suspension to bits to put on a new exhaust on, but you do if its in one piece. The answer is a new exhaust, which was on the cards anyway, because the front pipe is mild steel and needs changing.

 

Now I need to wait for that to arrive before I'm back on the road!

 

Ian

[anthonyt]

Ian, it is a good idea to have a spacer put inside the damper to shorten the stroke, without it you can get a nasty surprise, shouldnt cost you much.

[marvmul]

Ian, it is a good idea to have a spacer put inside the damper to shorten the stroke, without it you can get a nasty surprise, shouldnt cost you much.

Think this over and the conclusion will be different.

[jonlar]

You're right marvmul that would extend the travel, and unless I'm mistaken the dampers shouldn't be used to be the limiting factor at either end of the suspension travel - it'll knacker them - should be bump stops?

Edited May 18, 2006 by jonlar

[andrewt]

Marvmul may well have meant a spacer inside the body of the damper. this would limit the extension but not increase the closed length. It does means dismantling the damper though which could almost certainly not be done at home.

I did get Bilstein to rebuild my rear dampers & shorten them, but as my closed & open length were both too long i got them to reduce the body length & reduce the piston rod length, thus the suspension now bottoms on the bump stop but the spring cannot fall out on full droop.

This is really only practical on something like a competition damper which is designed to be rebuilt anyway. the other option is to fit a strap to limit droop, perhaps made of seat belt webbing, but make sure the bumpstops compress before the damper bottoms out otherwise you will break the shocker tower & this is a bitch to repair as access is all but impossible.

 

Cheers

Andy.

[Guest jeffremj]

Just a quick update on my suspension upgrade. The rear is all back together after a fight with the poly bushes. The 200lb shortened springs will come loose if you jack the car up - it's a shame the upgrade kit doesn't come with dampers about an inch shorter which would hold it all together. Not too worried about that as its all usually in compression but could be a problem if they lift the car by the jacking points for the MOT. Anybody had any problem with this?

 

Nope, because I used the proper springs from Triumphtune (Moss Europe). Which are now no longer available!

 

In the old days (pre-proper spring), Triumphtune supplied retaining straps to cure this problem.

 

The reason the 'proper' springs (and lots of other goodies, I guess) are no longer available is because Terry Hurrell (who wrote the Triumphtune Performance manual) had a stroke 4 years ago and all the supplier information for these bits were lost (it seems).

[jothecat]

i had the o/s rear spring pop out when I hit a pot hole. Had retaining straps put on very soon afterwards!

[anthonyt]

"Ian, it is a good idea to have a spacer put inside the damper to shorten the stroke, without it you can get a nasty surprise, shouldnt cost you much.

 

 

Think this over and the conclusion will be different. Marvmul"

 

It depends upon where you put the spacer! one side of the piston will increase problem other will reduce it, straps are really not the best way to go (but may be the cheapest).

 

I have had both spax and bilsteins fixed this way on my competition car over the years. I have also seen what can happen when a spring falls off the seat not very pretty!

[marvmul]

I didn't know it was possible to put a spacer inside the damper body. This solution makes the damper act as a stop when the axle goes in droop : can the damper and mountings handle this load? (on a TR7/8)?

[anthonyt]

Seems to! My race car does some very hard miles on the track and road rallies and havent had a problem in many years (since making the alteration), has to be a unit that has been designed to be repaired/altered.

[Ian Mould]

Thanks for all that. I think I'm minded to put the standard springs back in, or can you get the stronger springs at the standard length?

 

Ian

[anthonyt]

You can get higher rate springs at the standard length, but lowered higher rate springs are much better for handling.

[marvmul]

And remember to compare fitted lengths, not free length.