I've been told Leighton buzzard do not allow adjustments to the brake bias during the SVA, so I need to make an attempt to get it right beforehand. Any tips as to what I need to achieve by test braking?
My weight distribution is 70/30 ish to the rear, with wilwoods all round and identical master cylinders, I'm guessing i only need slight rear bias to account for the forwards weight shift?


James

Front wheels must lock up just before rears. This keeps the car stable as the (front) brakes begin to lock up by giving understeer. If you set them the other way 'round the rear end will overtake the front as it goes rapidly into oversteer.

From you picture I think you mean 30/70 weight distribution --- which needs roughly 50/50 brake pressure distribution in the dry.

Assuming you have the same sized calipers all round then set the balance bar in the middle or slightly towards the front master cylinder and try the braking at slow speed.

Even trying it at slow speed on the driveway will do for the initial setting but the surface must clean & dry so pick a dry day and sweep up any stones..
As long as the fronts lock clear before the the rears and you actually have working rear brakes you should be OK for SVA purposes.

[Edited on 6/2/09 by britishtrident]

i done it roughly by getting someone to apply the brake while i turn the front and rear wheels. bit hit and miss but it worked for the sva, even though when driving it the rears do tend to lock before the front sometimes. so there is a fair margin of error.

rob