Re: Brake reg. setting on rally cars

[ptimmerm@mashtun.JPL.NASA.GOV]

Good question Alex,

I have spent some time puzzling over this myself.  For 2wd
cars, you do run with lots of rear brake bias, and
normally have a souped up hand brake to use on hairpin
corners.  They typically don't lock, so you just yank and let go.
Now it you run with an open center diff, you can still do both
of those things.  I believe Ron Wood runs some pretty substantial
rear brake bias.  I have started running with my center diff
locked, so a handbrake turn is out of the question.  The effect
of lots of rear brake bias would simply be strain on the drive
shaft and diff, so I am not running that way.  I can run the
diff locked and not push (understeer) too much.  Some of that
has to do with the limited slip rear diff I am also running.  

Things have evolved quite a bit as AWD has come onto the scene.
First came diffs that were either open or closed.  Later the
top cars got electronically lockable clutch type diffs, you can
have them open quickly when brakes are applied, thus allowing
rear brake bias, handbrake turns, and even abs if they wanted it.

paul timmerman