On Wed, 16 Jul 1997 08:40:14 -0600 phil sims <phil@wilsongriak.com>
writes:
>This morning,a beautiful warm one at that, while approaching a nearly
>empty intersection, the only other car around (some early 80,s
>Chrysler
>gargantu-wagon) decided to lock-up all fours in front of me and
>present the
>side of her vehicle as a larger target for my MGA.
>
>The good news is that we did not exchange any sheet metal.(in part
>cause I
>DON'T tailgate)
>
>The bad news is that MY rears locked and the back end slid harmlessly
>about
>45 degrees before stopping.
>
>OK, so do I back off on the rear adjusting screws a click or two, or
>is
>there more to keeping the light back end rolling during a "panic"
>stop?
>
>THANKS!
>
Phil,
Don't do anything! It sounds like your brake bias is nearly correct.
If you think about it, given that one axle will lock up quicker than
the other, it is much better to have the rear lock first. The reason
being, with the rear locked, you have some directional control with the
front wheels which are still turning.
If, on the other hand, the front locked first, you have no (zilch, zero,
nada) steering control. A sliding tire cannot resist lateral forces, thus
it cannot apply a side thrust to the car.
True, the ideal would be to have neither lock before the other, but
this is probably an unobtainable ideal. In a panic stop (or high
performance braking maneuver for that matter), the front brakes do about
70-75 % of the work. with the weight transfered to the front axle area
due to the deceleration, the rear literally gets lighter, hence will lock
easier and quicker.
Don't back off on the rear adjusters, all this will do is to increase
the pedel travel but will have little effect on brake balance.
If you feel that the rear is locking way too soon, then it will require
a brake balance adjuster plumbed into the system. These operate by
limiting the pressure rise in the rear brake system, while maintaining
pressure on the front. Most good racing shops will have one.
Hope this helps
Rick Morrison
72 MGBGT
74 Midget
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