Tazz Kill Er

I looking to upgrade the brakes on my classic from the standard 2pot front 1pot rear, with all the options available for 4/6 pots etc is the master cylinder gong to be able to supply enough fluid and pressure to really make the most of the upgrade.

Chelspeed

Have a look at the piston diameters. Very very roughly - single pot piston about 2.5" diameter, two pot about 1.75" each, 4 pot 1.25", 6 pot about an 1".

Conclusion? They're all roughly the same area (and no I havn't done the sums I'm talking principles here) so the amount of fluid to be moved and hence the master cylinder design can be the same for all.

Tazz Kill Er

Ok based on those figures, the total pressure area of the pistons equal, excuse the crappy table.

Diameter, piston area, total area

62.5mm 3117 mm 3117mm single pot
50mm 1963mm 3926mm twin pot
37.5mm 1105mm 4420mm four pot
25mm 490mm 2946mm six pot

if the master cylinder pushes the same amount on each set of pistons the best resonse will be from the 6 pots and the poorest will be from the 4 pots as they will require a bigger push on the pedal to effect the same braking effort. i know that this is all dependant on pad to disc surface area but my concern is that just changing the calipers will not increase braking efficiency, per se only increase the pad to disc surface area and the driver makes the compensation for the extra pedal travel with his foot.

Chelspeed

As I said I hadn't checked the sizes they were made up to show the principle of different sized pistons. The actual numbers were clearly way off. See the other post for some real numbers that show 4 pot and 6 pot are virtually identical area.