I am doing a bit of a research project, mathematically modelling a production road car braking system. So far my model seems to work very well, but am I finding discrepancies in different caliper designs, where the fundamental stats (moment arm/piston area) are the same yet users reviews state a noticeable change in braking performance. I can only attribute this phenomenom to the difference in caliper stiffness and overall efficiency incorporating friction losses. Previously I had assumed the differences to be marginal at best and simply tagged the caliper clamp force equation with the overall system efficiency of a hypothetical 90%, however this is clearly not providing me with the level of accuracy I am seeking. I need to revise the model with a seperate effeciency input for the caliper, however I have no idea on any values to use for varying caliper designs. My initial thoughts: Single piston sliding - 80% Dual piston sliding - 82% Factory fit 4 piston fixed - 85% Lightwight aftermarket 4 piston fixed - 87% Twin block 4 pot fixed - 90% Mono block 4 pot fixed - 89% If anyone here would be able to shed any light on whether these splits are in the right ballpark, it would be greatly appreciated.