1993 "Maize & Blue" University of Michigan Solar Car - Vehicle Specifications

Vehicle Specifications

Body:

• Drag Coefficient, Cd: 0.115
• Frontal Area, A: 1.16 m^2 (12.53 ft^2)
• Drag Area, CdA: 0.133 m^2 (1.44 ft^2)
• Measured full scale in the Lockheed, Atlanta, Georgia, 4.9 x 6.1 meter (16 x 20 foot) wind tunnel with boundary layer blowing to simulate moving ground plane

Chassis:

• 6061-T6 Aluminum tubing space frame, 2.54 cm (1 in) OD, 0.11 cm (0.045 in) wall
• Carbon/Nomex body, Kapton insulators between panel and body
• Weight w/o Driver: 358 kg (790 lb)
• Length: 5.75 m (18.87 ft)
• Width: 2 m (6.56 ft)
• Height: 1.1 m (3.61 ft)
• Wheelbase: 2.2 m (7.22 ft)
• Track Width: 1.89 m (6.20 ft)
• Clearance: 0.45 m (1.48 ft)

Wheels and Tires:

• 36 spoke, 43.18 cm (17 in.) wheels with spoke covers;
• Michelin 43.18 x 3.18 cm (17 x 1.25 in.) slick tires @ 150 psi
• Number of wheels: 4
• Est. Tire Rolling Resistance Coefficient: 0.0060

Brakes, Suspension, and Steering:

• Hydraulic motorcycle disk front brakes
• No emergency brake (used chocks)
• Custom titanium suspension parts. Modified MacPherson strut with Monroe custom shocks in front, 86 lbf/in (15.1 N/mm). Separate coil spring. Trailing arm rear, with 236 lbf/in (41.3 N/mm) coil over shocks
• Rack and pinion steering with two redundant push-pull cables

Transmission:

• Direct drive chain to rear wheel
• 2.06/1 ratio typical

Electronics:

• Motor: Custom Magnetek DC brushless, 1.8 kW rated, 3.7 kW max, 2250 RPM, 100 volts, 14.5 kg (32 lb), 93% efficient at operating power level, 95% peak efficiency. Blower cooling
• Controls and Instrumentation: Constant power / constant speed motor controller. Telemetry of voltages, currents, temperatures, and speed to chase van
• Batteries: Eagle Picher, 3 parallel packs, 96 volts, 4.8 kW·h, 54 A·h, 154 kg (340 lb)

Solar Cells:

• Type of Solar Panel: Fixed panel with eight gently curved facets
• 8 facets of 3 modules each
• BP Solar Saturn Cells, Laser grooved, Monocrystaline Silicon, 7615 cells, 90% area packing, 17% single cell rated efficiency, 16.3% mean single cell observed efficiency measured at TRW in Redondo Beach, CA. Average was for 8000 cells processed. Overall panel efficiency 14.5%, 1300 watts peak. Note that for the World Solar Challenge approximately 40% of the array of BP cells was replaced with higher efficiency silicon cells manufactured by Dr. Martin Green at the University of New South Wales
• 8 AERL peak power trackers
• Panel voltage: 130 volts