Car suspension settings - doing it yourself?
Discussion
I was always very fond of the handling characteristics of my e92. Its basically got full bolt on parts - and ive just got it back now with up'd sway bars, control arms and links together with a new geo.
im really impressed with the front end turn in, its so much more responsive now - but the rear has become way too sorted - so much so it almost feels like traction control is interfering in when the rear tyres do find grip.
on the limit it feels more familiar with a mid engine car now with all 4 tyres sliding - before i could best describe it as the rear would rotate around, instead of the whole car moving from the middle (i hope that makes sense)
so i got thinking, this is prob due to running more negative rear camber and more toe. could i buy some tools and mess around in the garage myself? ive always heard suspension settings was one of those things is best to "use your guy" for
what a bout getting some car scales to get the weight balance sorted at least?
im really impressed with the front end turn in, its so much more responsive now - but the rear has become way too sorted - so much so it almost feels like traction control is interfering in when the rear tyres do find grip.
on the limit it feels more familiar with a mid engine car now with all 4 tyres sliding - before i could best describe it as the rear would rotate around, instead of the whole car moving from the middle (i hope that makes sense)
so i got thinking, this is prob due to running more negative rear camber and more toe. could i buy some tools and mess around in the garage myself? ive always heard suspension settings was one of those things is best to "use your guy" for
what a bout getting some car scales to get the weight balance sorted at least?
Yes you can do it in your garage with strings, a few bits of wood and an Iphone - will get you 90% of the way there but I would get a proper alignment done anyway - did you put M3 front lower control arms (assuming your car is not a M3 already) ? They are cheap and easy to fit. This might give you what you're after.
I do my own on the Elise. I can measure it more accurately than the granularity of adjustment available (except for toe, obviously, which is infinitely adjustable).
ETA: It does, however, take a bloody long time. I generally reckon a full day to get mine done. Caster is especially annoying to set because you have to take the top wishbone off on the Elise to change it and getting the shims back in is a pig.
ETA: It does, however, take a bloody long time. I generally reckon a full day to get mine done. Caster is especially annoying to set because you have to take the top wishbone off on the Elise to change it and getting the shims back in is a pig.
Edited by kambites on Monday 14th November 16:10
kambites said:
I do my own on the Elise. I can measure it more accurately than the granularity of adjustment available (except for toe, obviously, which is infinitely adjustable).
ETA: It does, however, take a bloody long time. I generally reckon a full day to get mine done. Caster is especially annoying to set because you have to take the top wishbone off on the Elise to change it and getting the shims back in is a pig.
This really ^^ETA: It does, however, take a bloody long time. I generally reckon a full day to get mine done. Caster is especially annoying to set because you have to take the top wishbone off on the Elise to change it and getting the shims back in is a pig.
Edited by kambites on Monday 14th November 16:10
It can be done at home, but it usually takes a long time (especially if doing it with axle stands and bits of string), jacking the car up and having to settle it etc before each reading... Most folks give up and get a specialist on it.
thanks for your reply everyone! seems to be a hassle indeed doing it yourself
so far the 50psi cheap rear tyres seems to be winning for me
otherwise, vs your normal average garage geo, is it worth spending that extra bit to get it done by a proper race team? its prob due time for a trip to team schimer in germany if you say so :P
so far the 50psi cheap rear tyres seems to be winning for me
otherwise, vs your normal average garage geo, is it worth spending that extra bit to get it done by a proper race team? its prob due time for a trip to team schimer in germany if you say so :P
Yep, its very easy once you have got it all set up.
I use 4 axle stands, 2 lengths of pvc waste pipe, and fishing line, (thinner than string, so i find it better for accuracy, but really easy to trip over it!)and a steel rule.
Take your front bumper off before so you can get to the toe adjustment without having to jack the car up every time. Loosen the toe adjustment bolts before you string up, so they aren't super tight while you are trying to avoid touching the fishing line!
I use 4 axle stands, 2 lengths of pvc waste pipe, and fishing line, (thinner than string, so i find it better for accuracy, but really easy to trip over it!)and a steel rule.
Take your front bumper off before so you can get to the toe adjustment without having to jack the car up every time. Loosen the toe adjustment bolts before you string up, so they aren't super tight while you are trying to avoid touching the fishing line!
Have a crack at doing it yourself, it's great fun if sometimes a bit fiddly!
I used to work on Caterhams, Ginettas and Formula Fords before I got a desk job, and learning the process took a bit of time. All used the bar and fishing wire method, with some metal rulers. First time I tried to set one up on my own, I left the roll-bars on and completely ruined the cross-weighting. Took as much time again to reset and do properly. Silly idiot.
As other posters have said. the actual adjustment of the toe, camber, tracking, ride height etc doesn't actually take very long; it's the process of taking off suspension components, jacking up, resting the car, remeasuring, reattaching.
One thing I would also recommend is make sure your wheels are true and straight, as this makes a bit of difference to the camber and toe if you're getting different measurements.
As well as that, make sure you measure consistently on a flat surface of wheels etc. Otherwise it's all a bit of a pointless exercise. Our Formula Ford's used to have a set of set-up wheels that never saw track time specifically for that purpose.
Other than that though, it's all just about being methodical and taking your time. If you're going to go down the corner weight route, I'd recommend Longeacre Compuscales, nice and robust and relatively simple to use. Just make sure you remember to put the front left weight on the display corresponds where you put it on the car. Another mistake I made learning! They are about £1000 to purchase, but good quality.
Good luck! There's loads of people with huge experience here, so if I've missed anything feel free to correct!
I used to work on Caterhams, Ginettas and Formula Fords before I got a desk job, and learning the process took a bit of time. All used the bar and fishing wire method, with some metal rulers. First time I tried to set one up on my own, I left the roll-bars on and completely ruined the cross-weighting. Took as much time again to reset and do properly. Silly idiot.
As other posters have said. the actual adjustment of the toe, camber, tracking, ride height etc doesn't actually take very long; it's the process of taking off suspension components, jacking up, resting the car, remeasuring, reattaching.
One thing I would also recommend is make sure your wheels are true and straight, as this makes a bit of difference to the camber and toe if you're getting different measurements.
As well as that, make sure you measure consistently on a flat surface of wheels etc. Otherwise it's all a bit of a pointless exercise. Our Formula Ford's used to have a set of set-up wheels that never saw track time specifically for that purpose.
Other than that though, it's all just about being methodical and taking your time. If you're going to go down the corner weight route, I'd recommend Longeacre Compuscales, nice and robust and relatively simple to use. Just make sure you remember to put the front left weight on the display corresponds where you put it on the car. Another mistake I made learning! They are about £1000 to purchase, but good quality.
Good luck! There's loads of people with huge experience here, so if I've missed anything feel free to correct!
stef1808 said:
on the limit it feels more familiar with a mid engine car now with all 4 tyres sliding - before i could best describe it as the rear would rotate around, instead of the whole car moving from the middle (i hope that makes sense)
Nope, no idea what you think is happening or what is wrong with that. I suggest you ought to be very clear in your own mind what you're trying to achieve, and understand enough about the theory of car handling to understand what options you have to achieve it, before you mess with the suspension settings of a car which is currently free of major handling vices.Suspension adjustments are one of those funny areas where the changes are very easy to make - often only needing a couple of minutes with a spanner or screwdriver - and the hard part is working out how the car is actually handling and how that was affected by those changes.
GreenV8S said:
Nope, no idea what you think is happening or what is wrong with that. I suggest you ought to be very clear in your own mind what you're trying to achieve, and understand enough about the theory of car handling to understand what options you have to achieve it, before you mess with the suspension settings of a car which is currently free of major handling vices.
Suspension adjustments are one of those funny areas where the changes are very easy to make - often only needing a couple of minutes with a spanner or screwdriver - and the hard part is working out how the car is actually handling and how that was affected by those changes.
your competently right and thanks for your reply. im going to start of stiffing the rear suspension and some more psi's at the rear. see if that helpsSuspension adjustments are one of those funny areas where the changes are very easy to make - often only needing a couple of minutes with a spanner or screwdriver - and the hard part is working out how the car is actually handling and how that was affected by those changes.
i still stand by what i said though: the handling characteristics with the m3 toe links, arms, sway bar etc is completely different now. about 15-20kmh faster corner speed/poised race car (with the sorted rear end) but not so much of a hoon machine anymore.
stef1808 said:
im going to start of stiffing the rear suspension and some more psi's at the rear. see if that helps
It sounds as if you've had a handling upgrade which has worked (more grip and better handling balance) but you decided you preferred the old tail-happy oversteering characteristics. In that case you might consider talking to the people you had do the work about what you want and see what they suggest. I can understand the preference for oversteer (as long as you know how to cope with it and are willing to accept responsibility if you don't) but over-inflating rear tyres and setting the rear (damper?) stiffness too high is going to compromise the back end grip generally. Once they understand the characteristics you're trying to achieve, your handling specialists can probably advise you how to achieve it without compromising the rest of the handling or ride comfort.Of course the other way is to look at this as an excuse to add more power.
GreenV8S said:
It sounds as if you've had a handling upgrade which has worked (more grip and better handling balance) but you decided you preferred the old tail-happy oversteering characteristics
this, but, im very happy with the front grip now. its miles better, just not happy with the rearquick update:
put a a few more psi's at the rear, and put the rear rebound (ohlines) on the stiffest setting (not recommenced/safe!!)
but.... I havnt giggled in my car like that since i was 17 and got my first rwd car - and ive driven some cool stuff also since then :P
the rears light up in any gear when on the boost
put a a few more psi's at the rear, and put the rear rebound (ohlines) on the stiffest setting (not recommenced/safe!!)
but.... I havnt giggled in my car like that since i was 17 and got my first rwd car - and ive driven some cool stuff also since then :P
the rears light up in any gear when on the boost
Gassing Station | Suspension, Brakes & Tyres | Top of Page | What's New | My Stuff