Doug I wrote:
Also as a FYI .... brake pressures can get up to around 2000psi and the temps can get 400+, so yeah, nylon is not a good idea.
Although they might is certain circumstances get that high many lightweight racing master cylinders specify 1500 PSI as the max design pressure for the system. These are primarily used on 2 master setups.
It's easy to calculate your line pressure max: ( panic stop may go much higher, depends on driver leg strength )
Pressure = foot pressure * pedal ratio / ( (Master piston dia/2)^2 *3.14159 )
or with normal parts and a single 7/8" master simple or duplex like factory street
line pressure = 200lbs * 6 / ((7/8 / 2)^2 * pi )
1996 PSI = 1200 lbs / 0.601 in^2 Pretty close to your 2000 PSI level.
With dual masters and bias bar centered divide by 2 for 998 PSI per circuit.
Clamp force at the wheel is similarly easy:
use only one side's pistons ( double sided brake calipers push against each other )
clamp force = line pressure * total piston area
= 1996 * (area of 2 pistons * 2" dia)
= 1996 * 2 * 1^2 * 3.14159
12541 pounds = 1996 P/in^2 * 6.28 in^2
So those big new mustang front calipers squeeze the rotors with 6 tons of force at 200 pounds of pedal pressure... No wonder they flex a bit
How much brake torque will that generate?
11" mustang rotors, 5" effective radius Moderate performance pads 0.5 COF
brake torque = Clamp force * effective rotor radius * Coefficient of friction
2612 Ft Lbs = 31352 Inch Lbs = 12541 * 5" * 0.5
Our tires are 26" dia so how much, assuming perfect traction, decellerative force could one wheel produce.
force = 2612 ft/lbs / (13"/12"/ft) per rotor side
force = 2411 pounds per pad = 4822 per wheel
2 wheels * 4822 pounds of braking force at 200 pounds pedal pressure from the fronts only.
That's with moderate street pads. Full race pads have a COF closer to 0.7, soft street pads more like 0.39.
When they get hot and or glazed the street pads COF goes down, race pads should stay stable.
El Capitan de los Bastardos De Lemons
1993 Linco Mark Ate
1957 Renault Dauphine
Driver with LemonSpeed's V6 Mustang