I was reading through the "Wiki" section, someone is trying to build a digital or other kind of gear indicator, it seems that a lot of people mess with circuits and logic etc.
How could you build a digital or analog (gauge) readout to show instantaneous mpg.  Then you would be able to see the best gear vs. speed combination.
These GS do not have Fuel Injection, so you would have to measure gas flow (very small Q) vs. speed somehow. 
[I haven't made the jump to a GS yet, so forgive my question- does the GS have a speedometer cable?]
Perhaps an electronic speed detector, like on bicycles, could be used for the speed input?
Years ago, my friend had a "Mileage meter" in his Impala, I think it was just a fancy vacuum gauge though.

The biggest problem with this idea is that GS doesn't even have fuel gauge,
to calculate mpgs users use the tripmeter readout versus fuel spent which in itself measured at your next refill
I don't know of any accurate fuel measurement devices that  could be incorporated into the GS fuel supply
to give you digital readings,but if there is one ,then it could be done theoretically (from the standpoint of electronics engineer)

GS has a speedometer cable,though many owners also use digital bicycle type speedometers with more tripmetering options
and accuracy

Not easily.  Due to the lack of sensors on a GS, you're pretty much going to have to start from nothing.  Even the speedometer is analog.  You have no way of easily measuring the flow rate of the fuel instantaneously.  You have no air flow sensor by which you could infer the fuel consumption.  I wouldn't even attempt to do this on a non-fuel-injected vehicle.

But that's the challenge of it! 
I will come up with something like this, try for a while, finally give up....  but it's worth it.

You have fun with that.  I have better things to do. 

They're not cheap, but I've installed a few of these for aircraft applications:

http://www.floscan.com/html/blue/aviation.php

Use a magnetic pickup to determine wheel speed.  Interface the flow rate and compute MPG.  There are loads of microcontroller development kits out there.  Many microcontrollers now have de-bouncing circuits, A-D converters, power supplies, display drivers, and other goodies built-in.  It is possible you could get away with one DIP package.   

While you're at it, might as well do the tach and speedo.  Hell, there are floatless capacitive fuel senders available for under $120.  Channel that into an unused A-D and have a fuel gauge too!  (See Aircraft Spruce and Specialty item #10-24770)

Just a few thoughts.

Quote from: Egaeus on April 14, 2007, 03:48:46 PM
You have fun with that.  I have other things to do. 

FIXED...but then I am an electronics geek and it sounds like GeeP is too.

I spent my Saturday working on two filters for my Spectrum Analyzer project. One is a 300 MHz interdigital bandpass filter, the other a 10MHz "classic" bpf.

+1 to all the above comments on sensors. I've thought at some length about "conversion modules" for the GS. In short they would be small electronic modules to replace the speedometer cable and RPM cable interfaces. Just unscrew the cable and insert into the drive hole. Of course electronic gagues would take the place of the originals. This would then allow monitoring of those two values by some sort of ECU. The late models of GS have a TPS (throttle position sensor) with the newer ECU that seems more uP based.

That would give us RPM, Speed and TPS. If we could monitor fuel flow then that could give us the variables for MikeNW's idea.

Anybody want to donate a 2004+ ECU and carbs for some noninvasive testing and development? I could get to this sometime in the next 5 years. 

Quote from: starwalt on April 15, 2007, 11:06:58 AM

Quote from: Egaeus on April 14, 2007, 03:48:46 PM
You have fun with that.  I have better things to do. 

REFIXED...but then I am an electronics geek and it sounds like GeeP is too.

I spent my Saturday working on two filters for my Spectrum Analyzer project. One is a 300 MHz interdigital bandpass filter, the other a 10MHz "classic" bpf.

+1 to all the above comments on sensors. I've thought at some length about "conversion modules" for the GS. In short they would be small electronic modules to replace the speedometer cable and RPM cable interfaces. Just unscrew the cable and insert into the drive hole. Of course electronic gagues would take the place of the originals. This would then allow monitoring of those two values by some sort of ECU. The late models of GS have a TPS (throttle position sensor) with the newer ECU that seems more uP based.

That would give us RPM, Speed and TPS. If we could monitor fuel flow then that could give us the variables for MikeNW's idea.

Anybody want to donate a 2004+ ECU and carbs for some noninvasive testing and development? I could get to this sometime in the next 5 years. 

Don't get me wrong, I like electronics and microcontrollers and all of that, but why solve an already-solved problem on a platform that's probably the least conducive one possible for it? 

For one thing, it is generally easier to develop your own sensing solutions rather than use the OEM.  Try finding an application datasheet for some no-name un-numbered XYZ proprietary sensor module.  The only way to figure out what it can do and how it works is to smoke a few (dozen).  In addition, most OEM engine management systems are encrypted.  I found that out analyzing the bus on the computer in my 1990 Dodge to determine a fan relay fault.  (Turned out to be a blown power transistor which took 2 days to find under half an inch of potting compound.)

Spectrum analyzer...  I guess you're not a channel surfer?   

The plug-and-play sensor idea is a good one!  I made an optical encoder for my VW Fox when the speedo went out.  It was an aluminum cylinder about 3/4" diameter by 1.5" long that screwed into the speedo cable port on the transmission.  Inside, I used an optical emitter/detector to sense the position of an 1/8" hole in a 3/8" diameter drum.  On the computer side I used a Z-80 with a simple program to drive a few 7-segment LED display units for speed and mileage readout. 

I never did get the circuit fully tuned, every now and again it would run away.  (De-bounce problem combined with oil leaking into the #1 prototype encoder because I neglected to provide for an oil seal)  However, the trip meter was accurate to .01 miles. 

All that to save $180 on a new speedo...   

Would a better application be to develop  a low fuel sensor?  MPG is easily calculated while at the gas pump.

My R6 has a feature in the computer where as soon as the fuel falls to a certain level, the fuel indicator turns on and a special counter turns on.  This counter counts the miles that you've been riding while the low fuel indicator has been on.

IMO that's more useful.

Quote from: annguyen1981 on April 15, 2007, 02:37:44 PM
Would a better application be to develop  a low fuel sensor?  MPG is easily calculated while at the gas pump.

My R6 has a feature in the computer where as soon as the fuel falls to a certain level, the fuel indicator turns on and a special counter turns on.  This counter counts the miles that you've been riding while the low fuel indicator has been on.

IMO that's more useful.

They want instantaneous gas mileage, as in, what am I getting RIGHT NOW. 

You don't need to measure the actual fuel flow to get close to your instantaneous MPG. Aircraft do because they can adjust their mixture to compensate for altitude, plus the fuel flow is high enough that a fuel flow sensor can be resonably acurate.

On the GS, a vacume or manifold pressure (MP) gauge coupled with RPM and MPH would do the trick, since the mixture is (or should be) fairly constant.

It would be something like (MP*RPM)/MPH

Manifold pressure is simply the absolute pressure in your intake, where Vacume is how much less pressure you have in your intake compared to the atmospheric pressure.

It should be possible to do without too much trouble.

Quote from: starwalt on April 15, 2007, 11:06:58 AM
Anybody want to donate a 2004+ ECU and carbs for some noninvasive testing and development? I could get to this sometime in the next 5 years. 

Hi, starwalt! 

It should only take me about 5 years to do something with ratbike, so I'll send you her bits in 5, k? 

Edit....oh....2k4+....nevermind! 

why waste time fighting ROCK SCIENCE

ride 100 miles....think to self...hey I should think about getting some gas

ride a little further and switch to reserve and continue conversation with
self....hey I got a short time before I'm walking....better get some gas

run out of gas....and the conversation with self gets ugly....you stupid.....ya should have got gas at 148 miles.....think about that next time you get to 147....stupid rednek

also why an instantaneous readout.....sounds like the old Vac doohickey in a ford....coasting down a hill in nertral could get you 120MPG for a few seconds...but so what car still got 24mpg overall

Quote from: werase643 on April 16, 2007, 05:11:22 AM
also why an instantaneous readout.....sounds like the old Vac doohickey in a ford....coasting down a hill in nertral could get you 120MPG for a few seconds...but so what car still got 24mpg overall

+1

My parents had a '93 Lincoln Continental that had this feature.  Going down a hill with the foot off the gas would produce a REALLY high number such as 95MPG, but going up the same hill would produce something around 10MPG.  On average, the car got about 20-25MPG if I remember correctly.

IMO, instantaneous MPG is kinda useless.

 

Bring this thread back from the dead.

So....   Has anyone on this forum actually installed a Manifold Pressure (or vacuum) gauge on their GS?  I've been dreaming of doing it -- just because it would be neat.  Would a reading at the carbs (say, off the vacuum / synchronization ports) be reasonable?  Or do y'all think a gauge would have to tap into the manifold(s) directly?  I just wonder, because the vacuum ports that are internal to the carbs are so tiny.

Opinions?

Quote from: 5thAve on February 16, 2009, 11:03:01 AM


Bring this thread back from the dead.

So....   Has anyone on this forum actually installed a Manifold Pressure (or vacuum) gauge on their GS?  I've been dreaming of doing it -- just because it would be neat.  Would a reading at the carbs (say, off the vacuum / synchronization ports) be reasonable?  Or do y'all think a gauge would have to tap into the manifold(s) directly?  I just wonder, because the vacuum ports that are internal to the carbs are so tiny.

Opinions?

Couldn't you just stick a T in the vacuum hose going to the petcock? The tricky part would be not introducing a vacuum leak and making your bike run poorly, but assuming you could overcome that problem, you'd be pretty close... All you'd need to do after that is correlate engine vacuum and fuel flow then use the fuel flow and speed to figure out mileage. It doesn't sound impossible... The real question is: how often do you look at your dash? I barely even look at my speedometer, I'm not sure an extra gauge would get much attention....

Mostly a waste of effort - and adding distractions, which does not help you to ride safer.

A vacuum guage can use the tiniest port on the planet - no bulk flow is involved. One of the balancing ports would be fine.

The basic reality - drive like an old fart, get better gas milage.

Crank and wind, get worse gas milage. Regardless, get better gas milage than a car.

Instrumentation to accurately measure fuel consumption (rather than vacuum) costs more than the bike. Reviving threads which died because they were never that great of an idea does not make them that great of an idea.

Go Ride. Put this thread back in its grave and RIP.

OBD - On Board Diagnostics.

You need OBD2 for mpg read out. OBD 1 isn't even sufficient. Now in comparison to that a GS500 has OBD -2000. Yes negative 2000. So you upgrade it, 2002 times and it will be able to do that. Speedometer cable is there, but it will be entirely useless cos you need a speedo meter wire or wires for OBD2.

OTOH - most euro spec sport bikes since 2005 or 06 have OBD2. US - not quite but they are close.
Cool.
Buddha.