track fuel consumption

[james_mini_twin]

hi just registered, need some help with fuel consumption, does anybody know how much fuel they are using while racing or trackdaying. in an ideal world i would like to fill the tank with just enough to get me round with out running out.

[rigor]

TBH it's not the sort of thing I would rely on someone else's estimate for in a race. You could do what we used to do when I was racing cars...

At a test day (or trackday) fill the tank with a set amount of fuel (say 15 litres into a totally empty tank) and go out and do a set number of laps as if you were racing. (Out lap, 10 hot laps, then an in lap). Drain the remaining fuel out of the tank into a measuring jug and work out how much you've used. That will give you a good idea of fuel used per lap, then work it out from there.

[sv650k4]

Buy your self a sypon and sypon it out every run after a while you will start 2 get an idea of what your useing per run etc...and then you will only need 2 add 2 it rather than sypon!

;)

[G]

does fuel really weigh that much to care :confused:

[james_mini_twin]

it doesn't weigh that much, but for such an easy weight shed i think it is worth doing

[boo86]

I normaly run mine so if I look in the tank i can just see the petrol splashing when I wobble the bike around. That's pure scince for you. It's the wobble test. I've never ran out but been pretty close. We do 7 lap races. Croft, East fortune, Cadwell.
Or have a sh*t before the race, it'll wiegh more.

[Blue_SV650S]

I normaly run mine so if I look in the tank i can just see the petrol splashing when I wobble the bike around. That's pure scince for you. It's the wobble test. I've never ran out but been pretty close. We do 7 lap races. Croft, East fortune, Cadwell.
Or have a sh*t before the race, it'll wiegh more.

Water is 1kg/Liter ... I don't know what the specific gravity of petrol is, so lets just use the weight of water ...

A fuel tank is what 13L?

So I'd say it's gonna be easy to 'about right' say 3 liters more than you need. ... If you can 'pass' 3kg of waste in one 'sitting' ... well ... you need to phone forward to the local sewer shouting 'incoming'!! :D

I can't answer the OPs question directly as it is so track and riding dependent, even ambient and track conditions weigh in.

It's not just fuel weight on/against acceleration etc, having excess fuel slopping about in the tank is not good for stability either ...

As others have said, the only way is to test and measure consumption yourself.


p.s. My fill method is even more primitive than yours ... I just 'slosh' a random (but similar) amount in!!! :D

[BoltonSte]

Petrol is about 70% the density of water

so 3L over is ~2.1kg xs weight.

Ste

[Blue_SV650S]

Petrol is about 70% the density of water

so 3L over is ~2.1kg xs weight.

Ste

That is still a fairly sizable turd!! :D

[northwind]

Enormous poo aside... It still depends on how you ride, just like on the road. Mine'll drain a tank in 70 miles on track, but it's got a bit of a thirst when opened up. If you're towing ht ebike to the track just throw in a 5 litre pot of fuel...

[boo86]

Fill your tyres with helium. That'll be awsome.

Or alternativly, If petrol is 70% the weight of water their must be some weight saving to be had by filling the radiator and cooling system with petrol instead of water. Just don't come to any of my race meatings !

I think the moral is don't worry about a litre or 2 of petrol. Unless your fast as a fecker on fast pills it makes no difference a kg here or there. Start jogging and drop a few pounds !

[Blue_SV650S]

Enormous poo aside... It still depends on how you ride, just like on the road. Mine'll drain a tank in 70 miles on track, but it's got a bit of a thirst when opened up. If you're towing ht ebike to the track just throw in a 5 litre pot of fuel...

I get through ~30L on an SV trackday ...

[northwind]

Yah, but you're fast :D And probably covering about 50% more miles than most folks. Suppose it depends on the track too a bit, how much time you get, I drained mine almost dry on a half-day open pit at knockhill but then it's got a mean thirst on wide open throttle.

[Blue_SV650S]

Yah, but you're fast :D And probably covering about 50% more miles than most folks. Suppose it depends on the track too a bit, how much time you get, I drained mine almost dry on a half-day open pit at knockhill but then it's got a mean thirst on wide open throttle.


I do tend to do ALL the sessions (many people miss say the last one). I also let my bike warm up to full temp in the pits so I can rag it from the first lap (keep heat in the tyres), that has to use 1-2 liters over the day?

Buy yes, a bit more speed it going to take a lot more fuel ;)

[lukemillar]

That is still a fairly sizable turd!! :D

Someone poo-ed outside of work (in London) about a year ago and a swear this could challenge a 2.1kg weigh in. I almost took a picture, it was that impressive. :lol: