Awww F******!!!!!
Just realised my bloody computer calculator was square rooting the fecking thing & not doing Pi!!….
Wish I could find my old Uni calculator which I used for Structural engineering studies!!...
As pistons each side compared to one side, you need to double check you have the same volume of fluid to move so you hope that the two side moving half the distance of a single side will add up...
EDIT:_
Kicked the computer programme...
57mm piston is 2,551.75mm area.....
60mm is 2,827.43mm of area...
3.0lt rears at 2 x 42 pistons is 2 pistons at 1,385.44mm each or 2,770.88mm total....
PS & thanks for pointing it out...total face palm....on my part...I should know better than to trust the computer 100%!!....
It happens. I understand the volume of fluid, but you are only moving a fixed caliper piston half the distance of a floating caliper. So the math would be multiply by 2 for two sides of pistons, then divide by 2 for half the distance. This is the same as just calculating area/volume of one side of a fixed caliper.
I'm not quite sure how you got the 3.0T number for four pistons but in the end we match up.