Crimson Racing Wiki

Soft Lines

Subteam: SuspensionSubsystem: BrakesAssembly: Brake Lines and FluidCars: CR21, CR22, CR25, CR26I

Purpose

Carry brake pressure across the suspension movement to the calipers.

Function

Braided stainless flexible line, which resists expansion under pressure far better than rubber hose. Routed to avoid interference with suspension and steering components.

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.

Manufacturing Process

Cut to the modelled length and crimped.

Full Material List

Braided stainless flexible line.

Reoccuring issues

CR22 Issue Log, 2023-09-16, Suspension. The front right softline failed and brake fluid came out; the driver felt spray on their leg. The line was replaced. Because the failure was found by the driver rather than by inspection, brake line condition is now part of the drive prep checklist.

Still to document

Nothing in CrimsonStorage covers these yet.