How to test shock absorbers

[taylormj4]

Hi all,
What's the best way to test your shock absorbers ?

The rear end of my 450 seems a bit jumpy (steps out in a jump rather than due to power) when cornering and there's a slight clonking/rattling when driving over older road surfaces and when taking up drive. So suspect the shocks or suspension/bushes. Doesn't sound like anti-roll bar bushes.

I am running the standard shocks.

Things I've tried / intend to try:
1. I have tried pushing the corner down and watching return. Seems less damped than the opposite side and there is a creaking noise with movement.
2. This weekend remove wheel and inspect damper for leaks and suspension for faults

Anything else I can try ?

Funnily enough the shock/damper unit on this corner failed (snapped) in the past.

[taylormj4]

OK so inspection this weekend found the shock absorber on the offending corner to be wet with oil, so definitely shot.

So next question is what do I replace them with. The car is a daily driver (spirited when conditions allow) rather than a track day car (although I hope to do one some day).

So should I go for the later generation Bilstein or something else that is adjustable (Gaz, Nitron, Spax etc)
I understand the Bilsteins now have ride height adjustment but as I only just get over those speed pillow things as it is, I don't think that's of much value.

I read on PH that's it's worth getting new suspension "set up" but I guess that's when you have adjustable ones is it ? Presume I can just fit a set of Bilsteins with new springs and nothing else needed ?

Matt

Edited by taylormj4 on Sunday 8th February 21:45

[scotty_d]

I am not a Gaz fan, ran them in my chim and now in my classic mini, a cheap damper that does the job but the ride is a bit compromised, I use nitrons on the cerb with eibach springs and it is great on the road. Had protechs in my cerb before and found them good as well age killed them.

Wish I fitted nitrons to my chim about as good as you will get with out going ohlins and spending ££££......

To add a geometry set up is very worth while, if I make any changes I tend to drive 4 hours to track v road for a set up when passing as it really makes that much of a difference.

Edited by scotty_d on Sunday 8th February 22:05

[taylormj4]

scotty_d said:

I am not a Gaz fan, ran them in my chim and now in my classic mini, a cheap damper that does the job but the ride is a bit compromised, I use nitrons on the cerb with eibach springs and it is great on the road. Had protechs in my cerb before and found them good as well age killed them.

Wish I fitted nitrons to my chim about as good as you will get with out going ohlins and spending ££££......

To add a geometry set up is very worth while, if I make any changes I tend to drive 4 hours to track v road for a set up when passing as it really makes that much of a difference.

Edited by scotty_d on Sunday 8th February 22:05

Thanks Scotty,
Heard a lot of not-so-good stuff about the Gaz ones a couple of years ago on PH. Had thought that had been solved now but still not sure about those because of the history.

An Independent is also selling Protechs. Anyone any thoughts on those ?

Seems that for a full set of 4:
Bilsteins with the original Eibach springs (and same brand still used on the Sagaris I think) would be around £850
Nitrons would be around £1200
Protechs around £560
Gaz Gold Pro £670

I'm leaning toward the Bilsteins with Eibechs but it's a shame not to have the ability to tweak the suspension stiffness.

Edited by taylormj4 on Sunday 8th February 22:49

Edited by taylormj4 on Sunday 8th February 23:11

[K4TRV]

Matt,

YHM?

Protec will be on a par (financially and performance I believe) with Bilston, but adjustable (pay more and get compression & rebound adjustment) and costs will similar. All will require a proper set-up adjustment/alignment?

T

[blitzracing]

Fitting new dampers wont change the suspension geometry, just the damping rate, so if you buy adjustable simply set them up mid point, and then tweak the front and rear pairs together until you are happy with the ride and stability. BUT you need to check the ride height before you change the dampers, as then set the spring platforms on the new dampers up to give the same height if they are adjustable. This is important, as the suspension angles will change with ride height. Mind you the TVR suspension alignment system is horribly crude, so a basic check on a laser tracking set up should show you your camber / caster, toe angles that you can check against the manufacturer’s figures to see if anything is out in the first place as a separate issue.