Crimson Racing Wiki

Bias Bar

Subteam: SuspensionSubsystem: BrakesAssembly: Balance BarCars: CR21, CR22, CR25, CR26I

Purpose

Alternate BOM naming for the balance bar.

Function

See the Balance Bar entry.

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

Steel.

Reoccuring issues

Fault Vault, CR26I, Design, Compromised Failure. The master cylinder and bias bar combination had an extra degree of freedom, causing brake migration. Zip tying the master cylinders was the trackside fix; a different bias bar is the recorded proper fix.

Still to document

Nothing in CrimsonStorage covers these yet.