multi piston calipers 2

[oldfart2]

Good day all,
I have just joined your group and have a question or point I would like clarified.

In multi piston, ie. 4 or 6 spot brake calipers, is there a ratio or formulae for the difference in piston diameters that is prevlent in some of the OEM and aftermarket sets available.
Thanks in Advance

Paul
Brisbane
OZ

 

[GTMule]

Generally, as far as I know, the different diameters are only to help reduce uneven pad wear. In other workds, the smaller diameter piston recudes pressure on that end of the pad, which, for several reasons, helps the pad wear more evenly. You'll find plenty of racing brake setups, even 8 piston stuff with identical pistons, a matter of preference, I suppose (in theory, total braking force would be greater with two even pistons, given all the spaces contraitnts in a cliper, etc.)

GTMule

 

[shure7]

the different diameters are only to keep the pads wearing evenly. So if this doesn't matter ie(short distance race) where the pads will be changed or at least checked after each race i would use the largest piston's possible. If pad wear is an issue there are formula's to use that basically balance the pressure on the pad but writing out everything you need to take into account might take a while I would suggest you try to get your hands on a copy of Brake design and safety by Rudolf Limpert and look at pgs 60-63 for the equations and the drawings.

shure7