Suspension setup - How does changing ride height affect geo
Discussion
Difficult to explain without pictures but I have an issue where my car is too low for the Sprint I'm doing on Saturday. I didn't really realise until too late. My car is a Van Diemen RF01 (not a Formula Ford) and I believe it's just a case of adjusting the push rods front and back to get it to the right height(?)
If I do that, will it really screw up the geometry elsewhere or should everything remain the same, just with a higher ride height.
I appreciate the noob-y-ness of my question, I'm on a steep learning curve here!
If I do that, will it really screw up the geometry elsewhere or should everything remain the same, just with a higher ride height.
I appreciate the noob-y-ness of my question, I'm on a steep learning curve here!
get a straight edge on the wheels and use an iphone to measure the change in camber. You'll also be moving the roll centre, depending on how far you move it away from the centre of mass, you'll also need to adjust spring rates and ARB's, but unless you're raising it a serious amount I wouldn't worry too much.
Cant see why your camber would change with ride height alterations unless you are talking inches rather than the odd mm. On the various FFords I have run, (Swift, Ray and VD) ride height is camber neutral, the thing that changes tracking is camber changes from wet to dry and vice versa.
I would be more concerned about the rake of the car to be honest. Rake can affect the balance from front to rear, as can the amount of droop in the suspension.
You don't want to raise the front of the car via the pushrods whilst thinking you have bags of room under the rear. Also take into account the height of your tyres, in our ff1600, high tyre pressures for the wet can affect ride height.
Its a black art i'm afraid! Think it all through and measure before and after adjustments..
I would be more concerned about the rake of the car to be honest. Rake can affect the balance from front to rear, as can the amount of droop in the suspension.
You don't want to raise the front of the car via the pushrods whilst thinking you have bags of room under the rear. Also take into account the height of your tyres, in our ff1600, high tyre pressures for the wet can affect ride height.
Its a black art i'm afraid! Think it all through and measure before and after adjustments..
Edited by andygo on Wednesday 14th May 01:08
People get too caught up in technicalities. If it's a one-off event and you just need it a bit higher then take accurate measurements front and rear to a datum point from the ground .. raise the front and rear the same amount eg half an inch (to maintain the same rake as before)
Go out and drive the damn thing
Put it back to where it was when you get home again.
If changing the ride height a small nominal amount screws your tyre wear in only sprint type distances then then your car had more fundamental issues to begin with!
Go out and drive the damn thing
Put it back to where it was when you get home again.
If changing the ride height a small nominal amount screws your tyre wear in only sprint type distances then then your car had more fundamental issues to begin with!
You should get less camber as the suspension travels up (as in bump) with unequal length wishbone suspension (i.e. more negative camber). As the car rolls on to a corner the negative camber increases on the outside. If you up your ride height (the opposite of what happens to the outside in roll) you will increase (as in add positive) camber. You won't need to worry though unless you go up inches.
I'd be more worried about checking your corner weights if you're touching the push-rods. Just make sure the front two wheels are the same weight on a single seater but make your adjustments at the rear so your front rockers are at the same angle.
I remember setting up my FF1600 with loads of rake (rear higher than the front). That was a nasty oversteery pig to drive like that especially in the wet. Try not do that but make the rear 5-10mm higher than the front to give you a little rake.
I'd be more worried about checking your corner weights if you're touching the push-rods. Just make sure the front two wheels are the same weight on a single seater but make your adjustments at the rear so your front rockers are at the same angle.
I remember setting up my FF1600 with loads of rake (rear higher than the front). That was a nasty oversteery pig to drive like that especially in the wet. Try not do that but make the rear 5-10mm higher than the front to give you a little rake.
Edited by itdontgo on Saturday 17th May 20:23
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