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Please help me, im thick
tomgregory2000 - 23/7/09 at 08:31 AM

Ive been doing a bit of looking into a brake caliper upgrade.

Now can someone please tell me how i work out bore sizes between single sliding caliper and 2 pot and 4 pot calipers.

In the case of the sliding caliper do i treat it as a 2 pot to work out the total piston area?
Also looking at the wilwood calipers in the rally design cat they list the bore size of the caliper, now is this per piston? so to work out the total piston area i add all four together?

Tommy

[Edited on 23/7/09 by tomgregory2000]


mookaloid - 23/7/09 at 08:35 AM

You might or might not be thick but that's not a stupid question

I'm not sure about that either - I'm interested as I suspect that the answer isn't straightforward


alistairolsen - 23/7/09 at 10:14 AM

Im sure someone will know for sure, but here are my thoguhts:

To work out the size based on displaced fluid (so you dent end up with a readlly long pedal, one should assume the runout from the disk will be the same (pistons pushed back by the same amount) and compare the area behind the big piston in the sliding caliper with that of the area of two of the pistons on the 4 pots (movement is split between the sides ont he 4 pot)

to work out the stopping power one should take the area behind the piston on the slider and compare it with the area of all four pistons in the 4 pot (F=PxA)

Yes, the quoted bore size will be for one piston.


ghostrain - 23/7/09 at 10:09 PM

Go to Rally Design site...click on 'designing your 4-pot brake system' and it answers all your questions about calculating piston area for single pot sliders(treat as 2-pot),2-pot and 4-pot calipers.