Technically there’s no bonnet, it’s a glassfibre reinforced plastic cover behind the cockpit, but that’s a mere detail. GM said that its Whirlfire Turbo-Power unit ‘closely resembles a jet engine’, which is fairly spot on. Instead of a giant afterburner, the energy from the main engine was directed through the car, powering turbines that powered the wheels. The powertrain was developed by Charles L McCuen, head of GM’s research division.
You ready for the mildly complicated part? This is literally rocket science. Compressed air is shot into the engine at 3.5 bar, mixing with kerosene in the two combustion chambers and set on fire, the exhaust gases powering the turbine that compresses the air in the first place, then being sent towards the second turbine that powers the rear wheels via a two-speed transmission. Phew!
The wheels were designed with drums outside rather than inside the wheel, to help cooling (there’s no engine braking to help here, but there are giant air brakes on the fake delta wings), and rather terrifyingly the 35-gallon fibreglass fuel tank sits in the nose in front of the driver.
The engine produced 365bhp at 26,000rpm, making it even higher revving than a lightly modified Honda Civic.
Pictures: GM Heritage Center