What's the GPH on a Merc 850sci
 

What is the GPH on the new style Mercury supercharged 850's and 700's??

Im sure the smart craft stuff tells ya ,What have you all seen?

Thanks
Rob:drink:

850 (race) is about 60 gph

is that wfo?

I would of thought it would of be higher

thats pretty much an average number for a race, so yeah, pretty wfo... :drink:

Had to laugh.....:lolhit:

From what I have seen, EFI engines are generally pretty close to the HP divided by 12 for the WOT GPH usage.

Yes, that is pretty much what I was thinking, based on other Merc EFI engines. That puts the 850 closer to 70gph.

mid corner, drives turned, engines bound up and accelerating, you might get 65-67 gph, wfo in a straight line the engines really don't burn that much, especially in a cat.

Cat, V or cruiser, does not really matter that much.

For a given engine, if you make constant HP, for a specific period of time, you will burn relatively the same amount of fuel, in any boat. Weather we speak in terms of megajoule (MJ), or British thermal unit (BTU), a gallon of 93 gasoline, has a constant energy content, and can produce a specific amount of HP, in a given engine, regardless of the work the engine is doing. Remember 1 mechanical HP is equal to 550 foot-pounds per second, which is approximately equivalent to 745.7 watts, at does not matter how they are used, they take the same energy to produce.

If you run WOT for a specific period of time, the same engine in the cat, will get farther than the V, and the V will get father than the cruiser, but they will all burn virtually the same amount to fuel.

I understand that, I am just telling you we burn more fuel on acceleration courses than we do top speed courses. It only varies by a few gallons per hour. We account for the 60 GPH and usually have fuel left over actually.

and my notes from Merc say 62 gph for the race 850.

Calculation
 

62 gal/hr at constant 850 output is around 0.45 BSFC assuming 6.2 lbs/gal fuel density.

exactly what we had figured, and the fuel can vary from 6.0-6.3 depending on region of the country as well.

So how would you convert the 60 GPH to miles per gallon(mpg)?

I'm guessing .82 mpg??

Sean/guys do you all calculate mpg in the race boats?

Thanks for all the info
Rob:drink:

.75-.85 probably, really don't calculate that.... obviously would be effected by pace laps, milling, etc... we base fuel off of lap time and laps (total time of race).

Actually we do it more by weight over time to make sure we don't come in light. Cant burn more than 800 lbs or we will be trouble. Usually come in a little heavy which is a good thing. Those scales aren't always the most accurate, so you want a couple hundred lbs on your side.:lolhit:

when did you join a race team??

been helpin out the 850 fury boat for the last year and half or so... been doing the race thing for nearly 10 years now, you need to keep up better. :drink:

it appears so........:coolcowboy:

What about a 1075sci on GPH? Anybody know?

Rob:drink:

Dumb question here (I don't really follow/read up on all the rules for different racing classes), when you say race 850, you mean just data you have logged from racing, not that there is a pleasure 850 and a race 850 for some reason (rules)?

great information and makes lots of sense :drink:

race 850 is 6k instead of 5800, thats about the only performance difference. Most of the other differences deal with the crash boxes and ecu programing for them.

Hey Poker if you read on your own thread Griff pointed out Hp ~ 12 gives you gph which is = 89.583 may want to try it on your calc


Happy Holidays:drink:

If you use 65GPH for the 850 and if the 1075 has about the same efficiency, then it would be about 82GPH. Not sure how real world GPH numbers compare, but they are probably close.
The HP/12 is just a general rule thumb.

gal/hr = injector lb/hr / 6