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the quinner wrote:

R85/8 wrote:Edit: off to read up on this http://www.megasquirt.info/

The "micro" version of MegaSquirt is what you want...

Thanks for all that info.

From the searches I have done so far, that's the conclusion I've come to as well. I noticed on the Microsquirt forum there's a couple of people who have done it with BMWs, one with the carburettor version of the F650, and another with an RT.

twist wrote:...Gads! I hope this project continues because I really want to follow for curiosity's sake.

Well it started as idle musing, but it now looks like it's got legs. Something to do over winter to give me an excuse not to ride the bike on subzero days.

The MegaSquirt control unit looks like the way to go. You could probably couple that with R850R throttle bodies and injectors, you may even be able to use the throttle position sensors.

The total adjustability of the MegaSquirt will work out much better than using a stock control unit and trying to trick it with different sensors or resistors. Then some thought has to go into where to mount the cylinder temp and O2 sensors, and how many to use.

[quote="the quinner"

IF I were doing it...I'd use microsquirt to control both fuel and ignition...I'd incorporate throttle position, air temp, air pressure, cyl head temp. and lambda feedback. I'd use two Bosch ignition control units with built-in dwell triggered by the microsquirt to make a non-total-loss system.

For track use, the MAP sensor could be replaced by a MAF sensor and the O2 sensor feedback eliminated...but, the controller maps would have to be tweaked for ambient conditions for each outing. On a bike that will go up and down relatively big hills (relative to the change in altitude at a race track) and that will be ridden in varying weather, I'd want a MAP and O2.
[/quote]

Why do you feel you need a closed loop system for the street? If you have a mass air flow sensor, or (as you spec for your fantasy bike) an air pressure sensor, then the system is already responsive to elevation change.

Major Softie wrote:[quote="the quinner"

IF I were doing it...I'd use microsquirt to control both fuel and ignition...I'd incorporate throttle position, air temp, air pressure, cyl head temp. and lambda feedback. I'd use two Bosch ignition control units with built-in dwell triggered by the microsquirt to make a non-total-loss system.

For track use, the MAP sensor could be replaced by a MAF sensor and the O2 sensor feedback eliminated...but, the controller maps would have to be tweaked for ambient conditions for each outing. On a bike that will go up and down relatively big hills (relative to the change in altitude at a race track) and that will be ridden in varying weather, I'd want a MAP and O2.


Why do you feel you need a closed loop system for the street? If you have a mass air flow sensor, or (as you spec for your fantasy bike) an air pressure sensor, then the system is already responsive to elevation change.

Typicaly the O2 sensor gives the best info back to the control unit on what the mixture setting is at the moment, and best fuel economy as a result. Imput sensors such as temp, MAF and MAP still require the mapping to be correct, and like a carb, tend to end up a tadd on the rich side to avoid stumbles and flat spots. The O2 sensor will normally overide everything else at cruise.

Major Softie wrote:Why do you feel you need a closed loop system for the street? If you have a mass air flow sensor, or (as you spec for your fantasy bike) an air pressure sensor, then the system is already responsive to elevation change.

Well (with apologies to George Mallory)...because it's there (and, I guess because it's MY fantasy).

The Mega/Micro-Squirt has some nice data-logging features. Feedback logged from a wide-band O2 sensor will give very precise information about the other sensors and the system performance. IOW, it's much cheaper than extensive dyno time and much more accurate than seat of the pants and reading spark plugs after throttle chops. The choice of a MAP sensor vs. a MAF sensor is a pragmatic one...MUCH easier integration into what is essentially an ITB set up with (or without) a common airbox...certain types of MAF sensors might work, but the MAP sensor has fewer drawbacks...(which probably wouldn't be much of a consideration if this were just a fantasy).

So far, a lot of people in this thread have talked about the ease of bolting parts to the bike, but the difficulty in making it work. Lambda feedback makes it much less of a stab in the dark. Sure, it could be removed from the system once the tuning is done...but, why? O2 sensors are removed from factory systems to avoid the ultra-lean EPA mapping...forcing the system to run in the slightly richer "limp home" mode...or, a black box is put between the O2 sensor and the brain to slightly alter the output voltage to trick the computer into a richer mixture. None of that applies to a ground-up, one-off, aftermarket system.

There are definitely two schools when it comes to aftermarket EFI systems. There's the keep it as simple as possible crowd (e.g., SDS-EFI...off the shelf "simple Digital System" with push button tuning)...and, then there's the let's do it because we can crowd (e.g., Mega/Micro squirt...open source, wide variety of options, technical skills required). I've been researching aftermarket EFIs for years and honestly feel that both camps end up putting forth the same amount of effort...simple isn't always simple.

The reality is that carbs work very well on an airhead...one would have to border on insane to consider EFI

If you are still interested in fuel injection, I saw this ad for the Luftmeister system where he is asking $200.

http://marketplace.ibmwr.org/ads/view/id/193076

05hexhead wrote:If you are still interested in fuel injection, I saw this ad for the Luftmeister system were he is asking $200.

http://marketplace.ibmwr.org/ads/view/id/193076

Now that would be a whole ton easier than trying to modify a bunch of R850 parts to fit........... and work!

05hexhead wrote:If you are still interested in fuel injection, I saw this ad for the Luftmeister system were he is asking $200...

Thanks, I've sent an email.

R85/8 wrote:

05hexhead wrote:If you are still interested in fuel injection, I saw this ad for the Luftmeister system were he is asking $200...

Thanks, I've sent an email.

If you buy it, let me know...I have some documentation.

R85/8 wrote:

05hexhead wrote:If you are still interested in fuel injection, I saw this ad for the Luftmeister system were he is asking $200...

Thanks, I've sent an email.

So did I!