MPGuino on a motorcycle?

[Saskwatchian]

Has anyone successfully done it yet? I have read a couple threads where people have been talking about doing this but they always seem to fizzle out before they announce succes.

I bought a new to me 2012 Honda NC700X and think it would be fun to be able to see what kind of fuel economy I could get out of it.

If there are options other than the MPGuino I am open to suggestions.

[MobilOne]

I don't see why the MPGuino wouldn't work on a motorcycle. IIRC, all it requires is 12v, a speed related pulse and a fuel injector pulse.

[sendler]

I bought an MPGuino for my CBR250R but never installed it.

[austingsx]

The problem I would see is that the mpguino has no way of measuring manifold air pressure. MAP dictates the pressure at which the fuel is delivered and therefore the volume delivered per pulsewidth. On a motorcycle you will tend to vary the throttle/MAP and gear selection more than with a car in general in city use. Not saying that it won't work but given the small fuel volume of fuel and greater variance of engine operating speeds, the result will not be reliable or often repeatable. A fuel fill-up log dealing with the 3 or so gallons every 120-200 miles will be far more accurate. I'd recommend the fuelly app.

[DXTercel]

Originally Posted by austingsx

The problem I would see is that the mpguino has no way of measuring manifold air pressure. MAP dictates the pressure at which the fuel is delivered and therefore the volume delivered per pulsewidth. On a motorcycle you will tend to vary the throttle/MAP and gear selection more than with a car in general in city use. Not saying that it won't work but given the small fuel volume of fuel and greater variance of engine operating speeds, the result will not be reliable or often repeatable. A fuel fill-up log dealing with the 3 or so gallons every 120-200 miles will be far more accurate. I'd recommend the fuelly app.

A motorcycle is not going to have a variable pressure fuel system, just variable volume by pulse width via the injector. It wouldn't work any different than it would in a car. I can try it too. I have a spare mpguino and a bike (13 ninja 650) that has a mpg gauge built into the instrument cluster. A great test would be to throw my guino on for a tank and see how far off it is.

[austingsx]

Well there ya go, it seems it actually be more accurate than a car with manifold regulated fuel pressure. My assumption was based on a road trip I made through the mountains; my 'guino readings were very off. Usually I'm in coastal plains or small hills. The continuous climbs with low MAP used considerably more fuel than a more even terrain.

[Saskwatchian]

Cool, thanks guys. I was hoping for a "I've done it and it works!" but this sounds promising. I do believe I will order one and hopefully be able to install it in February, then I will just have a couple more months to wait for the roads to clear so I can test it.

[zroadster]

Originally Posted by austingsx

Well there ya go, it seems it actually be more accurate than a car with manifold regulated fuel pressure. My assumption was based on a road trip I made through the mountains; my 'guino readings were very off. Usually I'm in coastal plains or small hills. The continuous climbs with low MAP used considerably more fuel than a more even terrain.

Well of course. I live in the mountains. Typically going up hill drastically reduces MPG. My Focus may be stock but it will still only manage 10-14 mpg going up hilly terrain, even at economical speeds. They weren't off, that's really what it takes to go up a mountain.

Most modern cars don't regulate fuel by pressure but by pulse width. Fuel pressure MUST remain constant, with only injector pulse width being changed. Some vehicles do regulate fuel pressure by speeding up or slowing down the pump, my focus is one of them, but it does it because it is a returnless type fuel system. It maintains a constant 40psi and wont run right if it is more than 3 psi more or less than that.

There ARE systems that regulate pressure to adjust fuel input. Bosch made them for Porsche in the 70s and 80s called the CIS. Constant Injection System and anyone who has owned one of these cars can tell you they are a royal pain in the tush to try to keep in optimum tune. I can tell you from first hand experience, if you don't have the OIL CAP tightened with a good gasket in it the AFRs will be off, it will stumble, and cold starts will suffer.

[zroadster]

Originally Posted by Saskwatchian

Cool, thanks guys. I was hoping for a "I've done it and it works!" but this sounds promising. I do believe I will order one and hopefully be able to install it in February, then I will just have a couple more months to wait for the roads to clear so I can test it.

let me know how it works! I have a 2014 Ninja 300 that I would love to have an instant MPG gauge on to help keep tabs on my riding on longer trips for range. Though, Trips through the local twisty roads, I wont be so worried about it