Suspension Setup queries
#1
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Suspension Setup queries
So I've got a new toy, a Westie. It's
The previous owner had AVO adjustable shocks fitted with competition spec springs (which have a fairly low spring rate - but I haven't been able to take them off yet to see what rate).
When two up in the car, over bumps, under power the prop contacts the underside of the handbrake mechanism because it's compressing too far and the bumpstops obviously aren't in place!
I'm investigating the options for higher rate springs and adjusting the ride height, and in the meantime I've stiffened up the rear a bit to cope better with initial compression. However, just 5 clicks (out of 22) make it a LOT stiffer, so I've knocked it back by 2..
I know I could ask this on the westie board, but seeing as I know some of you lot I thought I'd try here instead - might make an interesting read for some others considering a proper susp setup on their S too.
In adjusting the stiffness of the dampers, the initial compression is less, because of the speed at which the oil can get through the shock, but eventually it will compress too far. What affect will this have on the handling? I guess the rear will be less compliant and make it a bit more skittish on bumpy corners? in doing this will it transfer some of the weight to the front and induce more understeer - because of the changing load on the front as the rear goes over bumps?
My other options are ride height and stiffer springs. I guess ride height is the least likely to affect the balance of the car? as with me in it it'll just compress down to a simlar height as with a smaller driver - but could max out the spring before the prop contacts..
I can't get my head around the affect stiffer springs will make to the handling Any ideas?
The previous owner had AVO adjustable shocks fitted with competition spec springs (which have a fairly low spring rate - but I haven't been able to take them off yet to see what rate).
When two up in the car, over bumps, under power the prop contacts the underside of the handbrake mechanism because it's compressing too far and the bumpstops obviously aren't in place!
I'm investigating the options for higher rate springs and adjusting the ride height, and in the meantime I've stiffened up the rear a bit to cope better with initial compression. However, just 5 clicks (out of 22) make it a LOT stiffer, so I've knocked it back by 2..
I know I could ask this on the westie board, but seeing as I know some of you lot I thought I'd try here instead - might make an interesting read for some others considering a proper susp setup on their S too.
In adjusting the stiffness of the dampers, the initial compression is less, because of the speed at which the oil can get through the shock, but eventually it will compress too far. What affect will this have on the handling? I guess the rear will be less compliant and make it a bit more skittish on bumpy corners? in doing this will it transfer some of the weight to the front and induce more understeer - because of the changing load on the front as the rear goes over bumps?
My other options are ride height and stiffer springs. I guess ride height is the least likely to affect the balance of the car? as with me in it it'll just compress down to a simlar height as with a smaller driver - but could max out the spring before the prop contacts..
I can't get my head around the affect stiffer springs will make to the handling Any ideas?
#4
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I'm not an expert, but after jumping from a "soft" 04, into Craig's Nitroned 00, the car was too skittish. It had snap oversteer, no warning. Less rebound would help as it wouldn't react so harshly to attitude changes. Probably softer springs would help.
So you have a dilemma as normally you need to stiffen it up, and drop the car slightly to counter act for the less settling when you get in it. but because the ride height might be too low, it might be worth just stiffening it, keeping the ride height the same and see how it goes.
Suspension is both an art and a science. You need something that suits your driving style.
{EDIT}
Kobe knows more than me.
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\/
So you have a dilemma as normally you need to stiffen it up, and drop the car slightly to counter act for the less settling when you get in it. but because the ride height might be too low, it might be worth just stiffening it, keeping the ride height the same and see how it goes.
Suspension is both an art and a science. You need something that suits your driving style.
{EDIT}
Kobe knows more than me.
|
\/
#5
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it's a very general question.. stiffer springs.. handling..
surely roll will be less.. which is advantageous in some circumstances to keep the contact patch more optimised, on the other hand - less grip on bumps..which can reduce traction out of a corner..or braking into it.. the car can hop. If you watch the super slow mo of the F1 cars hitting the curbs.. the wheels are hanging in the air for quite some time!
weight transfer happens faster.. which can be good/bad depending on how it is set up..
you can run a lower ride height.. and therefore lower COG.. which improves cornering speed and normally aero is better..
ultimately depends what you want from the car..? if it is just to stop it grounding out on regular roads (versus a flat track).. then adjusting the ride height might be simpler. Adding passengers is equivalent as reducing spring rate.. that's why 4up in a saloon car feels bouncy..
in terms of handling.. you need to do it as a package.. changing the rate will invoke new settings for ride height and dampers. Just be careful that the rate needed also depends on where the spring sits relative to the wheel/suspension.. i.e. how much mechanical advantage is being used against it.
surely roll will be less.. which is advantageous in some circumstances to keep the contact patch more optimised, on the other hand - less grip on bumps..which can reduce traction out of a corner..or braking into it.. the car can hop. If you watch the super slow mo of the F1 cars hitting the curbs.. the wheels are hanging in the air for quite some time!
weight transfer happens faster.. which can be good/bad depending on how it is set up..
you can run a lower ride height.. and therefore lower COG.. which improves cornering speed and normally aero is better..
ultimately depends what you want from the car..? if it is just to stop it grounding out on regular roads (versus a flat track).. then adjusting the ride height might be simpler. Adding passengers is equivalent as reducing spring rate.. that's why 4up in a saloon car feels bouncy..
in terms of handling.. you need to do it as a package.. changing the rate will invoke new settings for ride height and dampers. Just be careful that the rate needed also depends on where the spring sits relative to the wheel/suspension.. i.e. how much mechanical advantage is being used against it.
#6
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Originally Posted by chilled,Aug 15 2006, 04:16 PM
I'm not an expert, but after jumping from a "soft" 04, into Craig's Nitroned 00, the car was too skittish. It had snap oversteer, no warning. Less rebound would help as it wouldn't react so harshly to attitude changes. Probably softer springs would help.
So you have a dilemma as normally you need to stiffen it up, and drop the car slightly to counter act for the less settling when you get in it. but because the ride height might be too low, it might be worth just stiffening it, keeping the ride height the same and see how it goes.
Suspension is both an art and a science. You need something that suits your driving style.
So you have a dilemma as normally you need to stiffen it up, and drop the car slightly to counter act for the less settling when you get in it. but because the ride height might be too low, it might be worth just stiffening it, keeping the ride height the same and see how it goes.
Suspension is both an art and a science. You need something that suits your driving style.
I have a lot stiffer springs than most UK cars.. 515lbs.. and no snap oversteer
It takes some getting used to.. but the cars are very easy to drive, yesterday I was in the UK (ashford) - in the pouring rain.. driving around the roundabouts.. wondering what all this roundabout mayhem people are talking about. Granted I was using some road tyres - but they were half used ones
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#10
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too keep it on topic
here is the same corner.. 3 cars.. westie (i think).. my S2000 1up + big ben.. a standard S2000 1up - have a look closely at the ride heights and body roll.
then another corner with the same westie 2up and then 1 up.. big difference.. see how close the exhaust is to the road..(yes I am the heavy passenger)
sorry for bad pics but we didn't pay for them
here is the same corner.. 3 cars.. westie (i think).. my S2000 1up + big ben.. a standard S2000 1up - have a look closely at the ride heights and body roll.
then another corner with the same westie 2up and then 1 up.. big difference.. see how close the exhaust is to the road..(yes I am the heavy passenger)
sorry for bad pics but we didn't pay for them