rolling road

It always amazes me how much Hp is supposedly lost in the transmission. 50Hp is the eqivalent of 15, two bar heaters as a loss in heat. Yes there is a small amount of loss in noise, but the bulk is heat.

Could you imagine how much heat that is. I expect it would be enough in that small area of a gearbox to melt the aluminium case and cause the fibreglass around it to catch fire.

Gearboxes in possibly 200 Hp road cars used in competition that I have checked the temp on with an infra red device have only been around 130 degrees C at the track, and in normal road use around 70 degrees C. Hardly sounds 37 Kilowatts of heat to me.

Just my opinion.

I've had my GTA on rolling roads several times and a 50bhp loss through the transmission is about normal. Other UN1 cars I have had have been similar - 21 Turbos for instance also lose around 50 bhp. Remember this is total transmission loss so this is the resistance of gearbox, diff, driveshafts and driven wheels. An experienced rolling road tuner once told me he has seen cars lose 5bhp at the wheels just by increasing wheel diameter by an inch. Don't feel bad though I've seen Subarus lose 80bhp and anything 4 wheel drive will be similar in general.

Fat tyres make a big difference - look at all the eco experimental cars that use tiny engines or solar panels and wotnot. They run very narrow tyres at big pressures.

Same goes for cycling - when I use to tour and race (years ago!) I'd run the tyres on my racer at 100psi+ and they were ultra narrow. You wouldn't believe the difference it made in efficiency and even in top speed.