No life (a.k.a. DattoMaster)  
Joined:
2008/10/10 22:02
From Melbourne Australia (and likely under the car)
Group:
Registered Users
|
Not being a smartrrrs but how did you lower it and still have stock springs? And just how far is it lowered?
If the springs have been cut, that increases their rate but it also drops the suspension height, so for any given corner the total suspension compression (as in where it ends up, not the amount of travel from it's relatively lower starting position) will be lower than with std springs/ride height.
This is important, as it means you'll get to teh point that the lower control arm passes vertical and the outside edge of the control arm is 'higher' and the inner control arm bush bolt pivot point is lower.
I'm totally murdering the physics here but basically this combination can actually allow forces to 'unload' the outside front, instead of helpful weight transfer/downforce (evne though the car can 'roll over' the tyre itself can unload.).
It's a little bit like leaf springs if you use lowering blocks to the point the axle line is too high, then it will lose traction off the line under hard acceleration easier.
So, what I'm getting at here is that although this might sound totally backward, if you have soft springs and a lower ride height, then it could be so low it is unloading hte suspension, and one of the ways you can actually combat it is with slightly stiffer springs, or a slightly higher (but possibly still less than brand new factory spec) ride height.
You might also find that the shock damping rate on bump is too high now, and teh wheel is having trouble staying on the road in a corner with any minor undulations in the road. Worse still, if the shocks are too stiff, but the springs too soft, it will keep breaking loose as it can't ride the bumps well, but then won't have the spring rate to help push and get the downforce onto the wheel when weight transfer does take place during cornering (weight transfer not necessarily body roll).
If the control arms aren't on those bad angles,and the shockers are too stiff on bump (or a combo of that and the springs being too soft) then yes, less front bar or adding/increasing rear bar stiffness would be the go.
You can also try dialling in some toe-out. It's a no-no on street driven cars as it'll chew out the inside edge of the tread (esp with some neg camber in the mix too) but it will noticeably improve turn in and mid corner (and even to some extent corner exit) stability. It might make it a little more likely want to pull to one side or the other under very heavy brakes too.
As far as your camber settings go, they seem pretty good, certainly nothing there that would cause understeer - they'd be in a good range to help prevent it.
Last but not least - tyre pressures. I have nfi what tyres you are running, but if they are taller sidewall, or just average tyres in general, you can often get some decent turn in (with radial street tyres) and overall cornering predictability/stability from increasing the tyre pressures, up to as much as 40psi (but make no mistake, you_WILL definitely wear out the centre of the contact patch a hell of a long time before the tyres would otherwise have lasted for with more modest inflation pressures. Certainly experiment right up into the high 30s or above if you don't mind that trade off.
Posted on: 2011/1/21 17:55
|
Transfer
