Crimson Racing Wiki

Brake Pads

Subteam: SuspensionSubsystem: BrakesAssembly: Brake Calipers, Pads and Master CylinderCars: CR21, CR22, CR25, CR26I

Purpose

Provide the friction coefficient against the rotor and survive the temperatures a braking event generates.

Function

EBC sintered pads, selected to match the rotor material and the operating temperature range.

Design Process

No part-specific design process is documented. The Brakes subsystem design process applies: 1. Set tire loads at the maximum airspeed seen (90 mph): rear 291.60 lbf at max acceleration, front 454.21 lbf under braking, 427.97 lbf cornering. 2. Sweep master cylinder bore combinations against required pedal force and achievable deceleration, then select. 3. Run a transient thermal simulation of the rotor for a single braking event (2.4 s, 260 C initial, 90 W/m^2-K film coefficient, 0.8 emissivity, 25,375 W heat flux front) and import that thermal load into a static structural run (1.84 g deceleration, 12 MPa pad pressure, 707 N-m moment) with cylindrical and frictionless supports. 4. Compare candidate materials on peak and low temperature and on minimum factor of safety. 4340 gave 741.2 C high, 344.5 C low and FoS 3.6438, against Class 40 cast iron at 490.5 C, 256.5 C and FoS 2.1622. 5. Validate with brake rotor temperature sensors on all four corners and compare measured against calculated.

Full Material List

EBC sintered Double H pads for the Brembo P2.34 (coefficient of friction above 0.55). EBC GPFAX sintered pads for the ISR calipers, track use (coefficient of friction above 0.6).

Reoccuring issues

Non-uniform pad wear, which was one of the two problems driving the CR26I rotor redesign.

Still to document

Nothing in CrimsonStorage covers these yet.