First Chim - Newbie Suspension question
Discussion
Hi all,
Picked up my first TVR at the weekend, a 98 Avus Blue Chimaera. Really enjoying it so far but will be garaging it shortly to clean and paint the Chassis. I'll probably also Fit the Steve Heath drop links, and check the suspension and brakes while I'm at it.
One thing I have noticed with the car is that on bumpy roads, in particular the cobbled back lane to my garage, the suspension seems overly hard, its certainly harder than the other cars I've test driven. Looking through the pile of bills and service records that came with the car I found a bill for Joospeed Rear Springs and Dampers. I have done a search on the web but couldn't find any details. Anybody have experience of these, are they harder than the standard units and how much adjustment can be made to them. Sorry if this is an obvious question but any advise would be greatly appreciated.
Picked up my first TVR at the weekend, a 98 Avus Blue Chimaera. Really enjoying it so far but will be garaging it shortly to clean and paint the Chassis. I'll probably also Fit the Steve Heath drop links, and check the suspension and brakes while I'm at it.
One thing I have noticed with the car is that on bumpy roads, in particular the cobbled back lane to my garage, the suspension seems overly hard, its certainly harder than the other cars I've test driven. Looking through the pile of bills and service records that came with the car I found a bill for Joospeed Rear Springs and Dampers. I have done a search on the web but couldn't find any details. Anybody have experience of these, are they harder than the standard units and how much adjustment can be made to them. Sorry if this is an obvious question but any advise would be greatly appreciated.
Joo, can be reached at www.track-car-solutions.co.uk . A lot of his work is fine tuned to the customer requirements. Your dampers are pretty certainly adjustable BTW if you want to soften things up a bit. If you post what make they are someone could probably tell you how. If you have one of the more radical track setups, it is prob best to talk to Joo about how to change it, if you just want a more compliant version.
Dave
Link should work now, sorry
Dave
Link should work now, sorry
Edited by spend on Wednesday 31st January 23:45
Had a closer look at the shocks. The fronts look pretty standard, red spring on a yellow damper with no ovious adjustment, these do look a bit worn. the rears are different and must be the units from Joolspeed. These have black springs and a fair amount of adjustment there appears to be about 1.5-2" of thread below the spring. I'll need to get the right tool though before I can Adjust them. As the fronts are waorn I might just go for new ones all round. How difficult are new shocks to fit
Changing dampers is dead easy if you don't mind getting your hands dirty. Loading and unloading the spring on the damper can be more tricky, and potentially dangerous if it goes wrong.
Unless your ride height is so low that your suspension is running out of travel, the main thing that determines the ride comfort is the damper stiffness. This should be matched to the spring, so from a purist point of view you should change them both together (i.e. new softer springs to go with a softer damper setting) but you can get away with adjusting the damper a bit either side of the 'ideal' setting. The setting we're talking about is damper stiffness, which is almost certainly adjustable on those dampers (the vast majority of aftermarket ones are, and the ones Joospeed sold were good and would have been adjustable), I don't know what the adjuster looks like but it will probably be a screw or knob on the side of the damper. Conventionally, turn the screw/knob clockwise to increase and anti-clockwise to reduce the damper stiffness.
The big thread on the outside of the damper is for ride height adjustment, and won't affect the ride quality unless the car has dropped so far that it is hitting the bump stops. This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way.
Unless your ride height is so low that your suspension is running out of travel, the main thing that determines the ride comfort is the damper stiffness. This should be matched to the spring, so from a purist point of view you should change them both together (i.e. new softer springs to go with a softer damper setting) but you can get away with adjusting the damper a bit either side of the 'ideal' setting. The setting we're talking about is damper stiffness, which is almost certainly adjustable on those dampers (the vast majority of aftermarket ones are, and the ones Joospeed sold were good and would have been adjustable), I don't know what the adjuster looks like but it will probably be a screw or knob on the side of the damper. Conventionally, turn the screw/knob clockwise to increase and anti-clockwise to reduce the damper stiffness.
The big thread on the outside of the damper is for ride height adjustment, and won't affect the ride quality unless the car has dropped so far that it is hitting the bump stops. This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way.
Had another look and got right under the car this time. Looks like the rear shocks are Protechs. Found the adjustment wheel on the back which was set to maximum (assuming Clockwise is is stiffer). I've eased them back abit and will see how the car goes tomorrow. Hopefully this will cure it and I will only need new shocks for the front.
GreenV8S said:
The big thread on the outside of the damper is for ride height adjustment, and won't affect the ride quality unless the car has dropped so far that it is hitting the bump stops. This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way.
Never had my suspension geometry setup professionally after fitting Nitrons. Where is a good place to go in Herts area? And, what is the best ride height for handling/road use? My car currently rides very low.
Cheers, Jon.
Greenv8s said:
This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way
could you expand on this please? cos I have a set of Spax adjustables on my S1, and I always thought that those big ally rings adjusted the ride height and nothing else- ie no significant effect on handling* . . so once I could get over the local speed humps I left 'em alone. . .
cheers
pg
* I was thinking that adjusting this would just move the normal operating range of the dampers up or down within their full range of travel
Chimjunkie said:
GreenV8S said:
The big thread on the outside of the damper is for ride height adjustment, and won't affect the ride quality unless the car has dropped so far that it is hitting the bump stops. This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way.
Never had my suspension geometry setup professionally after fitting Nitrons. Where is a good place to go in Herts area? And, what is the best ride height for handling/road use? My car currently rides very low.
Cheers, Jon.
Topcats is probably the nearest to you near Aylesbury...got my Nitrons set up by them and very pleased. they race TVRs and are well respected for their knowledge in suspension set up. 01296 655109- speak to warren. not sure about the ride height though...
Adjusting the ride height... amongst the things that it does...
1. Changes corner weighting and static weight distribution. Adjusting ride height is one way of adjusting these parameters.
2. Changes the dynamic geometery such as camber and toe because the suspension is now working in a different range because of the height adjustment. The camber might change normally from 0 to -1 but now might change from -1 to -3.
3. Big risk of the springs becoming unloaded in droop and hitting bump stops in compression.
4. Changes the operating range of the shock absorber.
5. Changes the CofG of the car.
The amount of effect is dependent on how much mod is done and what components are used e.g. spring and shock length and so on.
1. Changes corner weighting and static weight distribution. Adjusting ride height is one way of adjusting these parameters.
2. Changes the dynamic geometery such as camber and toe because the suspension is now working in a different range because of the height adjustment. The camber might change normally from 0 to -1 but now might change from -1 to -3.
3. Big risk of the springs becoming unloaded in droop and hitting bump stops in compression.
4. Changes the operating range of the shock absorber.
5. Changes the CofG of the car.
The amount of effect is dependent on how much mod is done and what components are used e.g. spring and shock length and so on.
angus99 said:
Had another look and got right under the car this time. Looks like the rear shocks are Protechs. Found the adjustment wheel on the back which was set to maximum (assuming Clockwise is is stiffer). I've eased them back abit and will see how the car goes tomorrow. Hopefully this will cure it and I will only need new shocks for the front.
You want to get the damper on each end. Too short a spring can cause bad crashing - but just being hard is a combination o fthe spring and the damper adjuster. How was it when wound off all those clicks?
pg53 said:
Greenv8s said:
This is not something to be adjusted casually as it affects the car suspension geometry and handling in a big way
could you expand on this please? cos I have a set of Spax adjustables on my S1, and I always thought that those big ally rings adjusted the ride height and nothing else- ie no significant effect on handling*
Obviously you have to make sure the damper stays within it's working range, but even within this range if you change the ride height you can change the static geometry settings and also affect the dynamic (roll/pitch induced) geometry changes. The effects are quite subtle for small changes, but a collection of subtle changes can add up to a major change in the handling.
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