To keep oil at the pickup and at adequate pressure through every cornering and braking case the car sees, and to keep oil temperature below the limit without risking the water system.
A wet sump. A 5052 aluminium oil pan with an integrated baffle tray and a triple trap door system prevents oil moving away from the pickup under sustained lateral and longitudinal acceleration. A 6061 aluminium oil pickup with a revised aspect ratio sits in the pan, sealed with the OEM pickup tube gasket and retained by the bottom of the pan. A one-piece fibre-reinforced nitrile gasket, waterjetted for fitment, seals the pan dry with no sealant. A combined temperature sensor and drain plug reads oil temperature at the pan. A Setrab sandwich plate adapter at the OEM oil cooler location diverts oil out to a separate oil-to-air heat exchanger. Hot oil from the filter enters through the centre of the hollow oil cooler bolt; below 78 C an internal thermostat bypasses the cooler and returns the oil to the engine; above it, oil leaves through the top port, runs through the cooler and returns through the back of the plate. A custom cap acts as the oil filter while the OEM oil cooler bolt holds the assembly together and compresses the O-rings.
Move to oil-to-air. The OEM arrangement is oil-to-water, which ties the oil temperature limit to the water boiling point. Separating them allows a higher oil temperature limit: water boils at 126 C at system pressure, while the absolute oil limit is 140 C. The oil cooler rejects 21.5 hp at a 131 C inlet with an 11 C drop across it. Validate sloshing on a track, not in a spreadsheet. Two purpose-designed test tracks were laid out to combine high entry speed and heavy braking with sweeping increasing-speed corners, specifically to drain oil from the head and away from the timing chain galley at the same time. 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.
- Maintain anti-sloshing capability as lateral loads rise with the aerodynamic package. - Minimise system weight and complexity while providing adequate lubrication performance. - Allow optimal engine placement, which is why the pan profile matters. - Characterise the engine's heat load into the lubrication system on the dyno rather than inferring it.
- Oil starvation under cornering. This is the design driver; the trap door and baffle system exists because of it. - Oil getting pumped out of the pan faster than gravity returns it from the head. The identified fix is a deeper pan, which also gives more oil to cover the sump in cornering and lengthens the time the engine can spend at high g. - Gasket interface reliability at the pan flange. Addressed by stiffening the mounting flange. - Welded seam count on the pan. Addressed by moving to 5052 aluminium, which allowed fewer welded seams.
MATLAB for oil heat rejection back-calculation from logged data. MoTeC i2 Pro for oil pressure, oil temperature and acceleration during sloshing tests. The engine dyno for characterising heat load into the oil at peak power without the cooling system running. GT Suite planned for complete system analysis and accurate oil cooler sizing. Oil sample analysis for wear metal and additive depletion.