brake caliper pistons vs pad size

[PlacentaJuan]

i am looking at buying a 2 piston r33 rear brake caliper to use on my cressida, and after looking at the pictures of the r33 caliper i can see that the brake pads look to be about half the size of the stock rear cressida pads.

so the stock cressie rear pads would have about double the surface area, but half the power (single piston vs 2 piston) plus a smaller diameter non-vented disc.

however i wasnt expecting the pads on the r33 calipers to be so small, will it still be a significant upgrade?

[Officer Doofy]

You dont want upgraded rear brakes. You have enough trouble doing burnouts as it is..

[PlacentaJuan]

You dont want upgraded rear brakes. You have enough trouble doing burnouts as it is..

post reported for deletion and possible neg rep / ban

[Officer Doofy]

lolz da truth hurtz broz

So what disc are you planning on using, stock cressie??

[cambelt]

Hey Placenta do you find too much rear bias using the R33 brakes up front . My brakes work perfect but i supect the rear pads are wearing out to quick verse the front .

[Mike-e]

just because the pad is smaller doesnt mean it will stop less efficently than a large pad, remember its about pressure on the surface area.

example: clutches, the less surface area of an uprated clutch disc the more clamping pressure the pressure plate has over the stock full faced disc, if that makes any sense.

[RobertoX]

The pad area doesn't affect brake torque so much. It'll affect things like wear and fade, however you also have to take into account the pad material.

The things that affect brake torque are:
-Disc diameter (for brake calculations you measure this at the centre of the pad friction area. Larger diameter more torque.
-Pad friction, higher coefficient of friction, more torque.
-Piston size, for any given line pressure, the larger the piston size the more brake torque.
You use the sum of the piston surface areas for one side of the caliper. If it is a twin opposed piston (ie 1 piston each side) then you use the size of one piston only. If it is a sliding caliper with twin pistons (2 pistons on one side) then you use the size of both pistons.

So you know that the disc is smaller, but if the pads are smaller then the centre of the pad is likely to be further out towards the edge of the disc, therefore the effective diameter might be similar.
What size is the piston in the caliper? Is it a sliding type with 2 pistons or a twin opposed type?
Assume the pad lining is the same (you could probably get higher friction pads for both).
Is the cressi one vented? If so then cooling capacity might be compromised.

[PlacentaJuan]

Hey Placenta do you find too much rear bias using the R33 brakes up front . My brakes work perfect but i supect the rear pads are wearing out to quick verse the front .

i had ebc blackstuffs in the back that lasted through a set of greenstuffs and red stuffs in the front (plus a 'couple' of burnouts) and only changed them, ciz the caliper slider siezed and they wore down unevenly.

the back never locks up however, and only the front will have abs kick in so i dont know what that means.