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View Full Version : Bump steer limitation: Fox rack, SN95 Spindles, Ackerman mod


Ophitoxaemia
02-14-2011, 07:26 PM
Even with the highest setting (closest to the bottom of the steering arm) I've still got toe out on compression and toe-in on droop. That means I need to move the rack down or the steering arm attachment up.

Hard to move the rack down because I have it bolted to X-member and its on offset bushings, raised so the rack boss clears the X-member.

For autocross, would I be better off returning the rack to the stock position.

Mark I, SAI mod, custom lowers, monoball upper.

Other options?
David
02-14-2011, 09:37 PM
James, do you have the rack extensions on your car? I would start there.

David
R. Button
02-14-2011, 09:59 PM
David,

Rack extensions?
Bob Cowan
02-15-2011, 01:08 AM
Measure tow in and toe out at the front of the tire. Then measure toe in and toe out at the rear of the tire. Subtract one number from the other to get bump steer.

http://i13.photobucket.com/albums/a256/bobcowan/BumpSteer3.jpg
Ophitoxaemia
02-15-2011, 02:26 PM
No rack extensions yet, haven't found a source (hey does FFR sell them?) - (@ralph, the Fox rack is too narrow so you won't be able to get the bump steer right with just spacing from the steering arm.
Shade Tree Mechanic
02-15-2011, 03:27 PM
No rack extensions yet, haven't found a source (hey does FFR sell them?) - (@ralph, the Fox rack is too narrow so you won't be able to get the bump steer right with just spacing from the steering arm.

Yes they do sell them.