GL1100 with throttle bodies (Fuel Injection)

[DJ]

OK. It sounds like it's time for you to write a how-to booklet for the rest of us.

[socrace]

The controller I'm using now is very expensive, but will be working with a hacked Ford oem unit over the winter. Should be just as capable but a much better match cost-wise to the project.

[sunnbobb]

Keep on keepin on, we enjoy the lesson!

[kb0ou]

Socrace
I am very interested in this project, running a 79 with LD's manifold and pic-30 carb.
It does okay, very simple.
I have a whole set of 90's/carbs extra. Would like to look at putting one throttle body on the manifold with injectors on 90's (welded in).
This would simplify the set up as no synch of throttle bodies would be needed and injectors would be right on the head.
Need more info on computers etc.
Thanks,
John kb0ou

[GL Bryan]

Have you made headway on converting a Ford ECU? I am looking into this and would rather spend the money on efi than rebuild carbs. What about a Geo metro unit? It is set up for a 1000cc engine, although it is a three cylinder.

[socrace]

An update: have bench tested the Ford ecu using simulated sensors like the ones on the Wing and things look good so far, although still stuck on how best to mount a crank trigger wheel.
As for using the Geo Metro system, Its a interesting possibility but pretty sure the ecu has not been hacked.

[westgl]

Has anyone used stock carb's for metering Air Only (Not running any fuel to them) and use injectors with a fuel rail to each fuel Injector on each intake manifold.

thanks

Westgl

[socrace]

Hey westgl, that's some hardcore hardware in your garage!
Using carbs as throttle bodies makes alot of sense to me; takes
advantage of alot of the engineering that went into them as
far as induction tuning, linkage, etc goes. I would proably have
gone that route if the LTD setup hadn't been available as cheap
as it was complete with injectors, fuel rails and the rest of it.

[Don_Karlos]

Hi,
nice job! I'll convert my 1976 GL1000Ltd the same way. To westgl: Go to http://www.roadstercycle.com/index.htm and take a look at the cv carb to EFI conversion part of the web site. I'm currently adapting this idea for a GL1000 K3. When I'm finished I'll post some pictures of the adapters used instead of the CV slides. I'll use GSXR600 Injectors and a Megasquirt.
Greetings from Germany
Karl

[MSGT-R]

Just plain WOW! This genius engineering has endless possibilities.

[FirstYearDeek]

Generally carburetors have smaller throats than EFI throttle bodies because an EFI TB does not need to accelerate the air as it comes through (to create the venturi effect)

While you're not limiting the air flow by using carbs, there's an opportunity to open that sucker up and potentially get better top end.

The only other issue is that carbs have "leaks" by design and most EFI TB's are sealed tight and control idle air with a valve of some type.

-Deek

[fmutters]

ok here is a question for you ,,, say you take a tbi unit off of lets say a geo metro or something with the comperable displacement and instead of wiring a brain into your system what do you think about just wiring the injector to fire with the coils? the only downside i can think of to doing it like this is would not have the quick throttle response...but for a cruiser that really isnt extremely important

[macka]

ok here is a question for you ,,, say you take a tbi unit off of lets say a geo metro or something with the comperable displacement and instead of wiring a brain into your system what do you think about just wiring the injector to fire with the coils? the only downside i can think of to doing it like this is would not have the quick throttle response...but for a cruiser that really isnt extremely important

you might be able to flood it out if you crack it too fast. You need to have better control then just a fuel dump based on coil load.

[FirstYearDeek]

ok here is a question for you ,,, say you take a tbi unit off of lets say a geo metro or something with the comperable displacement and instead of wiring a brain into your system what do you think about just wiring the injector to fire with the coils? the only downside i can think of to doing it like this is would not have the quick throttle response...but for a cruiser that really isnt extremely important

The amount of fuel needed for the engine needs to be adjusted based on many variables. Not just RPM.

What you're describing is exactly the way older fuel injected (mechanical) generators ran. Generators run a constant speed and load doesn't vary much. All you needed was a choke to warm it up and to adjust for major load changes.

On an engine used for propulsion, the fuel required is mostly calculated with RPM and "load." Load is usually determined by measuring the vacuum in the intake manifold or sometimes with throttle position.

What you're missing by only using RPM is the ability to accelerate and decelerate.

A fixed fuel metering system prevents acceleration because to accelerate you need additional fuel and air. True, you need to create a rich condition in most cases to accelerate, but if you choke the air to create that rich condition, you've just restricted the amount of air and you will create a runaway rich condition and the motor would eventually die or seize.

A fixed fuel metering system prevents deceleration because to decelerate you need to starve the motor of fuel to create a lean condition. You could simply open the throttle to create that lean condition but you run a high risk of premature ignition and damage to your motor.

The simplest injection systems were the mechanical systems that varied fuel pulses based on RPM through a cam and varied fuel volume based on manifold pressure. Translating that into the electronic world is exactly what the MegaSquirt (and other EFI systems) do. The added advantage of getting electronics involved is that you can now adjust fuel based on any sensor on the engine: throttle position, oil temperature (or water temperature) atmospheric pressure, a valet switch, a rev limiter, etc. Most systems also incorporate ignition timing as well. The ability to control fuel and spark to these precise conditions is how you tune a motor to do everything well, and almost always better than the factory.

-Deek

[Old Fogey]

That's a great explanation!