Brake pad options for heavy duty front brakes on VF Commodore.

[Sir Les]

Hi Ron, I think you've got yourself a little confused on this topic. For starters, braking efficiency depends on a number of factors. These include the total swept area (the area of the annular ring of the rotor acted on by the pads), and the distance of the mean radius of the pad from the rotor centre (i.e. the length of 'lever' applying the braking force). From this it can be seen that having a larger pad size and bigger rotors should in theory give you better braking. Piston area doesn't have much effect, provided it's sufficient to apply the required clamping force to brake the wheels without needing a super-human effort at the brake pedal. The number of pistons pushing on the pads is largely irrelevant, except that multi-piston setups can give a more even clamping force spread over the length of the pad, which in turn leads to better pedal response and longer pad life.

Also, I think you've mis-remembered the formula for calculating the area of a circle, which is pi x radius². In the examples you've given above, you've used the diameter instead of the radius. The actual piston areas turn out to be 2769 mm² for the dual pistons, and 2826 mm² for the single piston. Not much difference at all, really.

There's a good explanation of brake upgrades here: https://www.fourwheeler.com/how-to/...s-what-to-look-for-when-buying-better-brakes/

 

[Ron Burgundy]

Hi Ron, I think you've got yourself a little confused on this topic. For starters, braking efficiency depends on a number of factors. These include the total swept area (the area of the annular ring of the rotor acted on by the pads), and the distance of the mean radius of the pad from the rotor centre (i.e. the length of 'lever' applying the braking force). From this it can be seen that having a larger pad size and bigger rotors should in theory give you better braking. Piston area doesn't have much effect, provided it's sufficient to apply the required clamping force to brake the wheels without needing a super-human effort at the brake pedal. The number of pistons pushing on the pads is largely irrelevant, except that multi-piston setups can give a more even clamping force spread over the length of the pad, which in turn leads to better pedal response and longer pad life.

Also, I think you've mis-remembered the formula for calculating the area of a circle, which is pi x radius². In the examples you've given above, you've used the diameter instead of the radius. The actual piston areas turn out to be 2769 mm² for the dual pistons, and 2826 mm² for the single piston. Not much difference at all, really.

There's a good explanation of brake upgrades here: https://www.fourwheeler.com/how-to/...s-what-to-look-for-when-buying-better-brakes/

That's an excellent write up.
I just never understood how going from dual piston caliper to single piston could be an improvement. Just did not make any sense. That article explains other relevant things to consider.
It appears that in VF scenario the biggest improvement comes from larger rotor and better brake pads. Holden also advertised this setup as including the large bore BMC but the were never able to confirm this when I actually made inquiries.