Robb

Does anyone know what the front/rear break bias is on a MY99 Scooby??? I would expect it to be about 70/30. Is it adjustable?

The reason I ask is that whilst my front wheels are usually covered in brake dust, there never seems to be any on the rear wheels. Is it possible that the rear brakes are not working as they should be?

Cheers

Rob

RichS

Mines the same mate. (MY00 UK turbo)

Same on every other car in our family.
(BMW 540i, Merc. CLK, Renault Laguna, Pug. 106)

Don't know if you can change the bias without changing the brakes.

Rich

Paul Wilson

Front brakes will always do more work than the rears, due to weight transfer to the front under braking etc.
It would be dodgy to attempt to change the balance as the last thing you want is the back locking up/providing more braking before the front, if you've ever driven a kart with rear wheel only braking you'll know what I mean.

SDB

Hi Rob

The problem is, the rears are so light under heavy braking that very little braking force would lock them.

This mean that the majority of braking force is applied to the front.

It is a shame really as it is staggering how much extra braking you get just by altering the brake balance back a couple of percent, but the car becomes much more unstable.

ABS helps this as it is able to allow more braking to the rear because it can handle the locking of the rears independantly.

Cheers

Simon

MartinM

I know a man that races a Vauxhall Corsa (a replacement for his Nova )

Allegedly, some people with similar cars (not him of course ) actually put axle grease INSIDE the rear drums and on the rear pads so that they get no braking force at the back at all.

Apparently with a FrontWD race car on a long bend on the absolute limit, touching (normal) brakes will cause an instant spin. This seems to make sense, but have I got the right end of the stick??

AndyMc

Hi

The rear brakes on the Impreza have a pressure limiting valve(on driver side strut) which makes sure you cannot lock the rear wheels under circumstances such as braking whilst turning or when the front brakes have faded and you are pressing the pedal like crazy trying to stop!.
This means the brake balance is not fixed but moves more to the front under very heavy braking.
Even cars with ABS can have this valve,any body know why?.

The rear brakes can be made to do a lot more work but as explained in the above posts its not a good idea for a road car.Its similar to manufacturers making cars with understeer built in.They are just trying to save us average drivers from ourselves!.

Some modern cars with the latest ABS or EBD (electronic brake-force distribution) do not have the pressure limiting valve but have sensors that measure your rate of turn and deceleration etc and change the pressue applied to each rear brake (and fronts) accordingly.

This makes the car very stable when braking in corners and provide better straight line braking than cars which only have the pressure limiting valve and older types of ABS.

Andy