Crimson Racing Wiki

Differential Oil

Subteam: PowertrainSubsystem: LubricationAssembly: LubricationCars: CR21

Purpose

Lubricate the differential clutch packs and gears.

Function

Castrol Syntrax LSD Fluid 75W-140 in the Drexler differential. LSD-specific fluid matters because the clutch packs' friction behaviour, and therefore the lockup characteristic, depends on it.

Design Process

No part-specific design process is documented. The Lubrication subsystem design process applies: 1. Set capacity and pan geometry from the packaging envelope and the CG target. CR26I: 1.95 qt pan, 3 qt system, low-profile design lowering engine CG by 1.6 cm on the earlier revision. 2. Design the baffle and trap door layout, keeping baffle clearances tight and stiffening the mounting flange to improve gasket reliability. 3. Size the oil cooler from measured heat rejection. 4. Select the oil to meet Yamaha's specification (API SP, JASO MA2) with wet-clutch-safe additives. 5. Validate on the sloshing test tracks, logging oil pressure against lateral and longitudinal acceleration. Test 1 minimum oil pressure 30.7 psi at 7,200 rpm with 1.41 g sustained for 1 s and a 2.21 g peak; test 2 minimum 31.3 psi at 6,000 rpm with a 2.02 g peak. 6. Send an oil sample for analysis after 500+ miles of track and dyno running.

Full Material List

Castrol Syntrax LSD 75W-140.

Reoccuring issues

None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.

Still to document

Nothing in CrimsonStorage covers these yet.