kWh

[RIPPERTON]

Ive just figured out my Blade uses 50kWh in a 20min session at the creek (4.5liters fuel). but probably only 25% of that is actually used to make the bike go forward, the rest goes up in heat
Thats enough to power a house with 3 ppl living in it for 2 days. !! :dohsmiley: :dohsmiley: :dohsmiley: :dohsmiley:

[RUSSELL]

what formula??

[Nuff]

But who had more fun? :D

[RIPPERTON]

what formula??

Calorific value of 4.5l of 98ron is 180mJ

[jasonbw]

Wind resistance/drag would be a huge factor in this right?

Weird but cool statistic, never though of power like that.

[RIPPERTON]

Wind resistance/drag would be a huge factor in this right?

Weird but cool statistic, never though of power like that.

Already factored due to fuel consumption but would be difficult to calc how much energy went into pushing air out of the way. At full throttle around 40% of the fuel injected into the engine burns after the exhaust valve has opened and is wasted energy. The flames you see coming out of a top fuel dragsters headers is what it looks like inside your headers when you are anything over 1/4 throttle, just proportionately smaller

A fuel consumption calc is really the only accurate way of finding out how much power youve used and how efficient your engine / bike aero is

[Captain]

Wind resistance / drag is exponential in nature. Not only, but nearly all the power is used for acceleration (friction through the road / bearings being relatively small), then 'a vehicle will travel at the same speed unless there is something slowing it down or speeding it up'. It's one of the foundamental laws of physics (it also includes direction), and the reason satellites can travel at 1000's of km per second. In our case, what's slowing it down is the air resistance, and we're effectively countering this by 'accelerating' at the same rate as we're 'slowing' (or more, if we want to speed up).

I saw a report on the world's fastest production car, some american 7 litre or something and they tested it on a high speed track. They had it all wired up, with a laptop inside and once they got up to top speed (350ks or so) the thing was sucking up fuel like there was no tomorrow just to remain at that speed. In fact, the only reason it has such a monster of an engine is to overcome air friction at those high speeds*

So I'd say yes, drag would have a huge impact in this.

* It might have been top gear, pretty sure it was Clarkson and even if I'm not a fan the science was interesting.

[jasonbw]

WOW !! 40% waste at full throttle???

Is this when they do that trick stuff like pneumatic valves etc?

[Kimbo]

You have to take into account an internal combustion motor is only about 35-55 % effecient at turning gasoline into power from the crankshaft. then losses through the gearbox. Also any blown engine will always be rich to help keep the combustion and exhaust temp to a satisfactory level on WOT.