07-05-2009, 12:15 PM #1
Modified FZR/SHO Fuel Consumption
I have a question/concern for all of the modified FZR/SHO's out there, especially owners of the MoTeC ECU. With all the MOD's, what type of fuel consumption are you getting now? For closed course fuel consumption is never an issue, but for endurance racing 60 miles to the tank is the standard. Out of the box stock the boat burns approx. 20.4 GPH at WOT. That gives it a range of 62.5 miles at 68 miles per hour.
What is the GPH with the mods that YOU have? In summary, I need to know if the boat can make it 60 miles or will I need to built an auxiliary tank for additional fuel. Also, can the MoTeC adjust the fuel burn rate to the point where we can lower the boost however, maintain top speed?
Thanks ahead of time for your responses.
07-05-2009, 04:16 PM #2
To make HP you need airflow through the engine, the more air the more fuel you gotta put in to match it.
Increase HP by 20%, fuel usage goes up approx 20%, but with increased HP comes increased speed so then it boils down to how much faster are you going for your extra 20% HP, maybe you are going 20% faster, in which case the fuel used per mile would be the same.
The std SHO engine is quite rich everywhere, at full throttle, at cruise, and at idle.
Our base tunes are more economical than the std ECU at cruise so customers can save fuel. At full throttle the set ups are a little leaner than std so it will be better on fuel but not by much.
However there is nothing stopping you tuning your engine to a leaner mixture.
You can definately save more fuel by fine tuning your exact set up.
My guess is up to 7% better at full throttle would be possible and reliable for long distance races, but you would need to be carefull.
07-05-2009, 09:58 PM #3
My calculations based on what your saying puts a 16 PSI Boost/8,000 RPM motor at approximately at 26 to 27 GPH (versus 20 GPH stock). With a WOT speed of 83 MPH. The range on the FZR (18.5 gallon tank) would range between 56 and 59 miles per hour. Which should be fine for a endurance race that normally maxes out at 60 miles tops. Nobody can keep it pinned 100% of the time normally, so getting the boat just over 60 miles to the tank should be doable.
The only way to know is to test it. Do these SHO 4 stroke motors dislike running out of fuel? Meaning would I take on any damage if I ran it bone dry?
My HP increase I used was 207 as a baseline with 310 as the modified HP (33% gain in HP). If the RIVA 16 PSI Wheel with the M400 pushes more than 310 hp, then my numbers are off.
07-05-2009, 11:47 PM #4
07-06-2009, 04:24 AM #5
I'm not sure how much you can get out of the tank. It's an 18.5 gal tank but the pump might not be able to get all 18.5 of it. Hmmmm.,.
The most I've ever put in the SHO when refueling is 17 gal, so I can tell you that you're good for at least that much.
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