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      10-21-2007, 06:05 PM   #110
GregW / Oregon

Drives: 2015 M4 Coupe, 2012 ML350
Join Date: Nov 2005
Location: Lake Oswego, OR

iTrader: (3)

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Originally Posted by swamp2 View Post
You continue to misrepresent my statements. I have never waivered on my belief that brakes are critically important. I think the jury is still out on the brakes but they COULD be the weakest point on the car. I suspect the brakes will be fine, even without the factory track pads, for all but the tracks that really torture ones brakes.

I always have and still do stick to my guns that rotor size, caliper size, the presense of a floating rotor and brake cooling are MORE important than the number of pistons (or the color of the caliper...)
Brake System Basic Facts
1) Line pressure can only be increased by either increasing the mechanical pedal ratio or by decreasing the master cylinder diameter. In either case the pedal travel will be increased.

2) Clamping force can only be increased either by increasing the line pressure or by increasing the diameter of the caliper piston(s). Increasing the size of the pads will not increase clamping force. Any increase in caliper piston area alone will be accompanied by an increase in pedal travel. The effectiveness of a caliper is also affected by the stiffness of the caliper body and its mountings. It is therefore possible to reduce piston size while increasing caliper stiffness and realize a net increase in clamping force applied. This would typically improve pedal feel.

3) Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque.

It is true that multiple piston calipers do not necessarily offer more clamping force than single pistons, but might offer more piston area making this possible.

Greg Lake Oswego, Oregon, USA
2015 M4 Coupe - Silverstone/Sakhir/CF
2012 ML350