Focus Fanatics - View Single Post - alignment specs for autocross
View Single Post
Old 08-29-2006, 09:47 AM   #7
SVT Robzor
Focus Fanatic
 
SVT Robzor's Avatar
 
Join Date: Aug 2005
Fan#: 26230
Location: Cumberland, Maine
What I Drive: 2004 CD Silver SVT

Posts: 1,578
FF Reputation: 5 SVT Robzor Good Standing Member
Buy-Sell-Trade Rating: (5)
Well, I'm not the most qualified person on here to hand out advise, but here's my thoughts. The H&R sway kit is 24mm front and rear I believe, which should affect your ride similar to my SVT stock setup at 21mm f/r, that being, tending to be pretty neautral. Difference is you'll roll less. Now your springs are biased stiffer towards the front, where SVT stock is biased towards the rear. With even tire pressures and OEM camber and toe specs (which SHOULD be pretty much 0* toe, slight negative front camber and around -1.5* rear camber, but I could be off) the SVT is pretty neautral with tendencies towards mild snap oversteer.

Your front suspension is comparativly stiffer, which will tend to add push, or understeer, to the ride, which will be amplified by the application of throttle. Conventional wisdom is that as a track progresses from
[Technical] -------> [High speed]
your suspension tuning goes from
[Oversteer] ------> [Understeer]
Because going sideways at the top of 4th = bad, but pushing the front end in a low speed corner is no good either.

This is all academic, I dont have a racing career to back any of this up, but I think its pretty solid so far.

What I'd do is keep your toe as close to 0* as you can. Maybe a slight rear toe out. Remember our multilink rear suspension has a passive toe-out under compression. You have a little understeer to tune out, but you can fine tune that with the KYB AGX's adjustable damping. Bring the rear camber as close to true as you can, lowered that car that should be around, what, -2*, -1.5*, something like that. I've seen setups before that aim for -0.5* front/-1.5* rear camber, which makes sense to me. Then I'd bias the suspension damping stiffer at the rear to help maintain front grip.

That should at least give you somewhere to start. If you end up needing less understeer later, rear toe is adjustable as I recall, or you could go back to your stock front sway bar.

Anybody want to back me up/tell me off? Second opinions = for the win.

___________________________
EDIT'ed a few times for typos.

EDIT: I assumed you had AGX's, the adjustable damping will be good to fine tune w/o going back for a new alignment. Barring that, change your relative tire pressures can help move the handling balance fore or aft slightly if need be. Info found on this page may or may not be new to you, if it isnt, please to not take offense. General suspension tuning wisdom: Linky
__________________
2004 SVT Focus
Custom front-bumper-mount bug guts; precision sprayed brake dust on OEM rims; 15% Pine Tree pollen over the clear coat.
No more SVT autocross, I drive the thing in the avatar.

Last edited by SVT Robzor; 08-29-2006 at 09:58 AM.
SVT Robzor is offline  
    Reply With Quote