Produce the power and torque that move the car.
A 2008 Yamaha YZF-R6: 599 cc inline four, 13.1:1 compression, naturally aspirated, 16,000 rpm maximum, running 100 octane gasoline.
Retained rather than selected each year. The justification: six years of knowledge and experience with this engine, an engine test stand designed and built around it, vehicle and test stand instrumentation harnesses designed for it, three functional assembled engines already owned, and an iterative year-to-year design process that only compounds if the engine stays constant. The downsides are stated openly: heaviest engine configuration commonly used by FSAE teams, higher cooling loads because power is only accessible at high engine speeds, and lower efficiency than a single or twin cylinder.
Cost to change: roughly 720 hours to redesign the test stand, roughly $3,200 in test stand parts, plus a new engine and its parts.
Characterised experimentally rather than from published data. Intake ports captured by pouring 2-part casting silicone into the ports, 3D scanning the molds and post-processing. Port flow measured on a flow bench with valve lift controlled by fine-pitch fasteners threaded into a plate bolted to the head, read on dial indicators, with an individually characterised bell mouth on the port inlet. Cam geometry measured with a dial indicator probing the lobe: exhaust 180 deg ECD at 0.050 in lift with 7.95 mm max lift at 245 deg ATDC; intake 200 deg ECD with 8.67 mm max lift at 475 deg ATDC; 115 deg LSA, 150 deg overlap. Valve spring curves from an MTS Exceed, maximum displacement limited by coil bind at 0.9270 in.
Purchased engine. From the cost report drawings and CAD: From the cost report drawings: BMRS Convulated Tube (Engine Inlet Tubing Drawing).
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.
599 cc, 4 cylinder, 13.1:1 compression, 16,000 rpm maximum engine speed, naturally aspirated, 100 octane gasoline, 135 lb wet weight. CR26I output: peak torque 36.8 lb-ft at 8,600 rpm, peak power 84 hp at 13,500 rpm. CR25: 36.5 lb-ft at 11,300 rpm, 79.5 hp at 11,500 rpm. Gear-limited top speed 82 mph. From the cost report drawings and CAD: Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. Engine Inlet Tubing Drawing (as drawn): 12.70, R1.27, 157.37, 15.74 Pump Line to engine Drawing (as drawn): 159.87, 15.99, 71.26, 7.13, 25.40, 2.54 Source: Cost report drawings: CR25/Powertrain/Design/Y - Cost Report Drawings/Cooling/Engine Inlet Tubing Drawing.pdf; CR25/Powertrain/Design/Y - Cost Report Drawings/Cooling/Pump Line to engine Drawing.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Cooling/Engine Inlet Tubing Drawing.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Cooling/Pump Line to engine Drawing.pdf and 2 more Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.