Spring length on the dampers

[Martin V]

Hi,

I had to take my dampers off front of my GT6 MK3 Front. PO had fitted bolts with thread “inboard” and fouling in springs plus ride height questions and amber shims to address. 
 

how long should the springs be off the car fitted on the dampers? Mine are 10” J think original spec springs. See pic.

[johny]

The measurement off the car doesnt mean much as thats the maximum length of the damper and nothing to do with spring length which either has to be measured removed from the damper (free) or on the car (fitted) with the manual test weight inside...

[Martin V]

Thanks Johny. I wasn’t sure if there was some height to aim for before fitting as they didn’t come off as straight forward as manual suggests. They wouldn’t clear the bridge that sits across the lower wishbones not allowing them to drop. I had to undo much more than planned.

[johny]

You have non standard adjustable dampers there and they look a bit longer than the usual ones which might explain why they were more difficult to remove. Anyway when installed with 400kg  of weight in the car the springs, if standard, should be compressed to about 8" long....

[Martin V]

On 28/11/2023 at 20:29, johny said:

You have non standard adjustable dampers there and they look a bit longer than the usual ones which might explain why they were more difficult to remove. Anyway when installed with 400kg  of weight in the car the springs, if standard, should be compressed to about 8" long....

Thanks Johny, yes they were about that length (8") when they were on the car although one was half inch longer. I'm taking the opportunity whilst they are off the car to take them apart, clean, paint and build back properly with them put on opposite sides. I guess if I try to compress fit them a little shorter than they stand currently it will make them easier to fit back on the car.

I believe shortening the static length before I refit will make little/no difference to the loaded length and ride characteristics as long as I only need to shorten them a small amount.

At least now the top wishbone mounting bolts will not be fouling the springs and the lower mounting bolts will be the right size as a 3/8" I found isn't good on the lower shock mounting when they should 7/16".

 

 

[Pete Lewis]

previous owners    there is a lot about with all the bodges and mis fits that go with years of misguided twiddling 

love em or hate em  rules apply 

keep smiling 

Pete

[dougbgt6]

I find things on my car and think "Who the hell did this?!!"  Oh,  

Doug

[johny]

1 hour ago, Martin V said:

Thanks Johny, yes they were about that length (8") when they were on the car although one was half inch longer. I'm taking the opportunity whilst they are off the car to take them apart, clean, paint and build back properly with them put on opposite sides. I guess if I try to compress fit them a little shorter than they stand currently it will make them easier to fit back on the car.

I believe shortening the static length before I refit will make little/no difference to the loaded length and ride characteristics as long as I only need to shorten them a small amount.

Are you sure your shocks are adjustable for anything other than damping? Spax do different types and the length adjustable ones have a threaded collar that needs a C spanner to turn....

[Martin V]

4 hours ago, johny said:

Are you sure your shocks are adjustable for anything other than damping? Spax do different types and the length adjustable ones have a threaded collar that needs a C spanner to turn....

Thanks Johny, yes you are correct. There is just the small thread at the top which gives a tiny amount of reduction if I can master the spring compressors tight enough.

My dampers just have the rebound adjustment. Managed to get them all stripped down so just the challenge of assembly later this week.

 

Thanks All for your great comments.

[johny]

ok but I cant see theres any length adjustment available at all. The nut at the top must be done up tight to hold the top of the damper against the top spring plate otherwise the it will be loose and possibly damage itself. If you use a compressor on the spring it will come free of the end plates as the damper being gas pressurised will stay fully extended. 

I think those shocks have a combined rebound/compression damping adjustment - many have found they can end up making the ride quite uncomfortable so leave the setting on minimum...

[Pete Lewis]

these are the ones  on the left  that have adjustable seats threaded to change the lower spring pan position .

ride adjustable dont have these but will have a knob/screw/device  to change the damping rates 

so the term adjustable has a wide span of meaning.

Edited December 5, 2023 by Pete Lewis

[Martin V]

Thanks guys, yes just the screw adjustment for damping. I’ve had both types in the past including fully adjustable tailor made Penske on single seater racing car.

They all came together nicely, I bolted down the top cap fully was whilst the springs were clamped and with them being that half inch shorter they both slid into position perfectly without any catching on the cross piece on the lower wishbone. 
 

After spraying the springs and Spax with a few nice coats of primer and black paint I think it looks quite respectable and I got rid of the Spax yellow which was really tatty and not fitting with car. The top caps came up nice and with new nuts I’m pleased with my efforts.

I even now fitted my refurbed original valances having fitted the top wishbone bolts correctly, fitted correct sized lower damper bolts and shimmed the lower to reduce my positive camber to 1 deg positive (unladen). I’ll consider another shim each side after driving a little as laden should bring it closer to 0 degrees anyway. Of course, Toe in was corrected after the shims were added.

Thanks for your help guys.