Engine
My requirements for the engine are:
- Light in weight. The 2003 Yamaha engine and gear box weighed in at 60.5Kg dry weight.
- More power. ~250bhp at the crank would be nice.
- >100lb-ft torque output.
- Rev limit around 12,000rpm
- Reasonable MPG figures. My Fury has averaged 28mpg over the last five years, which is pretty good considering the way it gets driven.
This car isn't about large amounts of horse power. There are many family hatchbacks with over 200bhp. In a 400Kg car, you don't need large power outputs to give it 'supercar' acceleration. I'd rather sacrifice power for weight. The numbers that count to me are on-the-road weight and bhp/ton.
Yamaha R1
My 'worst case scenario' is that I use a Yamaha R1 engine and end up with ~160bhp in a 400Kg car. This engine requires minimal modifications to work well in a bike-engined car and a tuned 4-2-1 exhaust manifold, uprated clutch, sump baffle and slight oil over-fill is all that is required.
160bhp in a 400Kg car equates to 400bhp/ton. To put this in context here are a few weights and bhp/ton figures of cars I'd be happy to own (from EVO Magazine:
- Bugatti Veyron Super Sport = 1838Kg and 654bhp/ton
- Ford GT = 1583Kg and 353bhp/ton
- Lotus Elise S2 SC = 870Kg and 254bhp/ton
- McLaren MP4-12C = 1434Kg and 419bhp/ton
- McLaren F1 = 1137Kg and 560bhp/ton
And yes, I know the weight of the driver becomes more significant as the weight of the car becomes lower but, trust me on this, it doesn't make that much difference.
Honda Fireblade
Andy Bates from AB Performance is using 2008 honda Fireblade engines in his race cars and is getting very good power outputs in excess of 180bhp. 180bhp in a 400Kg car equates to 450bhp/ton.
Suzuki GSX1300R / Hayabusa
The engine I currently have in mind for this car at the moment is a normally aspirated but modifed 2011 Suzuki Hayabusa 1340cc, in-line, DOHC liquid-cooled engine. Typically this engine requires a dry-sump installation when used in a bike-engined car.
Maximum power is 146 KW 195.7 hp @ 9800 rpm and maximum torque is 154 Nm @ 10200 rpm