Helper springs
Discussion
Hello all,
Im after some general suspension advice regarding helper springs, specifically (if it makes a difference) on Bilstein shocks like the ones in the pic I found below:
If you remove the "open" helper springs and replace with "closed" ones, I've been informed that this is of benefit when driving on track (as I understood it, this was because the main spring would be doing all the work all the time). However, I've been informed that doing this would have a negative impact when driving on the road. Would this be because the ride becomes too stiff as the shock would have less travel (I assume it would loose the additional travel of the helper springs?)?
Currently, the helper springs on the back of my car are compressed so that they are near enough closed anyway; its the fronts that have a bit of "slack" in the helper springs. The weight is all at the back of the car.
Any help much appreciated
Im after some general suspension advice regarding helper springs, specifically (if it makes a difference) on Bilstein shocks like the ones in the pic I found below:
If you remove the "open" helper springs and replace with "closed" ones, I've been informed that this is of benefit when driving on track (as I understood it, this was because the main spring would be doing all the work all the time). However, I've been informed that doing this would have a negative impact when driving on the road. Would this be because the ride becomes too stiff as the shock would have less travel (I assume it would loose the additional travel of the helper springs?)?
Currently, the helper springs on the back of my car are compressed so that they are near enough closed anyway; its the fronts that have a bit of "slack" in the helper springs. The weight is all at the back of the car.
Any help much appreciated
Edited by Toilet Duck on Friday 8th March 10:17
Helper springs are a bit of a half-arsed solution, to be honest, but at normal ride height they should be coil-bound anyway.
Their main function is simply to stop a too-short spring rattling round loose (and the tyre being completely unloaded and losing traction) when the suspension is at full droop.
They do have a potential secondary function in that they soften the initial contact when the wheel comes back up from full droop, whereas with a solid spacer you go directly from the tyre being completely unloaded straight onto the stiff main spring, so yes, solid spacers would affect the ride if you're dampers are regularly running at an extension where the helper springs are not fully coil-bound.
I'd suggest that there's something wrong with the car's set-up (spring rates/damper travel) if the front helper springs are not fully coil-bound at normal ride height, though - at best, they will give you a dual spring rate (ie. not truly progressive) whereby the initial bump movement is soft but then there's a relatively sudden step change to the main spring rate as the helpers go coil-bound. American racers sometimes run helper springs in this way (ie. not fully coil bound at normal ride height) and call them 'assist springs', but it's a bit of a crude, red-neck solution if you ask me.
If, for whatever reason, the suspension can't be made to work with single-rate main springs (and that in itself suggests that the basic suspension design hasn't been thought through properly, or is being made to do something it wasn't designed for), the more sophisticated solution would have been to use progressive rising rate springs.
Their main function is simply to stop a too-short spring rattling round loose (and the tyre being completely unloaded and losing traction) when the suspension is at full droop.
They do have a potential secondary function in that they soften the initial contact when the wheel comes back up from full droop, whereas with a solid spacer you go directly from the tyre being completely unloaded straight onto the stiff main spring, so yes, solid spacers would affect the ride if you're dampers are regularly running at an extension where the helper springs are not fully coil-bound.
I'd suggest that there's something wrong with the car's set-up (spring rates/damper travel) if the front helper springs are not fully coil-bound at normal ride height, though - at best, they will give you a dual spring rate (ie. not truly progressive) whereby the initial bump movement is soft but then there's a relatively sudden step change to the main spring rate as the helpers go coil-bound. American racers sometimes run helper springs in this way (ie. not fully coil bound at normal ride height) and call them 'assist springs', but it's a bit of a crude, red-neck solution if you ask me.
If, for whatever reason, the suspension can't be made to work with single-rate main springs (and that in itself suggests that the basic suspension design hasn't been thought through properly, or is being made to do something it wasn't designed for), the more sophisticated solution would have been to use progressive rising rate springs.
TheLastPost said:
Helper springs are a bit of a half-arsed solution, to be honest, but at normal ride height they should be coil-bound anyway.
Their main function is simply to stop a too-short spring rattling round loose (and the tyre being completely unloaded and losing traction) when the suspension is at full droop.
They do have a potential secondary function in that they soften the initial contact when the wheel comes back up from full droop, whereas with a solid spacer you go directly from the tyre being completely unloaded straight onto the stiff main spring, so yes, solid spacers would affect the ride if you're dampers are regularly running at an extension where the helper springs are not fully coil-bound.
I'd suggest that there's something wrong with the car's set-up (spring rates/damper travel) if the front helper springs are not fully coil-bound at normal ride height, though - at best, they will give you a dual spring rate (ie. not truly progressive) whereby the initial bump movement is soft but then there's a relatively sudden step change to the main spring rate as the helpers go coil-bound. American racers sometimes run helper springs in this way (ie. not fully coil bound at normal ride height) and call them 'assist springs', but it's a bit of a crude, red-neck solution if you ask me.
If, for whatever reason, the suspension can't be made to work with single-rate main springs (and that in itself suggests that the basic suspension design hasn't been thought through properly, or is being made to do something it wasn't designed for), the more sophisticated solution would have been to use progressive rising rate springs.
Thanks very much for the detailed reply, thats very informative Their main function is simply to stop a too-short spring rattling round loose (and the tyre being completely unloaded and losing traction) when the suspension is at full droop.
They do have a potential secondary function in that they soften the initial contact when the wheel comes back up from full droop, whereas with a solid spacer you go directly from the tyre being completely unloaded straight onto the stiff main spring, so yes, solid spacers would affect the ride if you're dampers are regularly running at an extension where the helper springs are not fully coil-bound.
I'd suggest that there's something wrong with the car's set-up (spring rates/damper travel) if the front helper springs are not fully coil-bound at normal ride height, though - at best, they will give you a dual spring rate (ie. not truly progressive) whereby the initial bump movement is soft but then there's a relatively sudden step change to the main spring rate as the helpers go coil-bound. American racers sometimes run helper springs in this way (ie. not fully coil bound at normal ride height) and call them 'assist springs', but it's a bit of a crude, red-neck solution if you ask me.
If, for whatever reason, the suspension can't be made to work with single-rate main springs (and that in itself suggests that the basic suspension design hasn't been thought through properly, or is being made to do something it wasn't designed for), the more sophisticated solution would have been to use progressive rising rate springs.
The suspension set up is as it left the factory, so nothing has been altered. I've experimented with the 10 way damper adjusters but have not touched anything else.
Someone with the same car recommended switching to closed helper springs so that the main spring does all the work all the time, but they only use their car on track. I use mine mainly on the road (although I plan to do around 5 track days a year) so didn't want to do something that would have an adverse effect on road driving.
Thanks again for your reply, thats a big help
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