hey guys,
has anyone installed speedways motors rear disc brake kit?my question is if the front caliber and rear caliber are the same size,does a proptioning valve need to be used?if not does the car stop the same on all four wheels?

From my understanding/experience, even if the calipers are the same front/back, you still need a proportioning valve. The rears do not need to do as much work so if there is as much pressure as what you supply the front, the rears will lock up.

Normally the rear caliper pistons are about 1/2-3/4 the size of the front (in area, not diameter) AND usually use a proportioning valve.

Brakes like that (same on all 4) are made for race cars with a dual master cylinders/ balance bar setup. In this case the two master cylinders would almost certainly be different diameters.

can i use the same valve as my disc/drum setup or should i get a adjustable valve.or is it just not possible without two master cyclinders?

Brakes like that (same on all 4) are made for race cars with a dual master cylinders/ balance bar setup. In this case the two master cylinders would almost certainly be different diameters.

It also depends on weight distribution and many other things.
Rear engine cars might have rear brakes very close to the same as the fronts, but there is still weight transfer and front/rear tires to think about, +++++

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