Fuel management

[Boogieman142]

Has anyone in here used a fuel management system and which one?

[87turbodance]

I've only used megasquirt. I have it on my turbo 2 sundance. I plan to use megasquirt 2 when I turbo my 3.0 in my '89 spirit. I'm also considering losing the distributor and fitting EDIS 6 with a crank position sensor. Megasquirt works great and it's cheap. It requires a little more technical knowledge when compared to some of the other systems, though.

[mwinkle353]

I think Chris is using a TEC3 unit on his newly acquired Custom-built 3.0L Nitros fed monster. But time will tell as to how well that system works. I think he's still breaking in the motor yet.

[irocelectric93]

I know Apexi seems to be a popular one.....however i dont know how well it works or easily.

[mwinkle353]

Are you talking about the SAFC?

If so, that's just a piggyback unit that intercepts the voltage from the MAP sensor and alters it going to the PCM. From what I hear, it has it's ups and downs.

On our motors, the MAP sensor sends a signal to the PCM and then the PCM uses that, and other sensors, to determine fuel and ignition control. When you alter the signal to change the fuel delivery, you're also changing the ignition timing. It's a good "Band-aid" solution for controlling larger injectors. But I'd rather use it with a FMU, if you're going with boost.

Using the two side by side, you can rely on the SAFC less, thus altering the ignition maps less. But the downfall to this is that you could have had a Stand-Alone ECU installed for just a few hundred dollars more and have much better control over the fuel and ignition.

Personally, I like adding a seperate fuel injector controller. Doing this, you'll have to add extra injectors in the intake system. This way when you're not into boost, the stock PCM controls the fuel delivery, and runs just like it did from the factory. But when you start to get into the boost, the factory fuel system is supplimented by the extra injectors and controller. This way the only limits are the injectors you add and the MAP sensor of the controller. But then again, you get into the cost of the system. And for what thier worth, add a couple hundred dollars more and you can have a stand-alone setup.


The only other viable solution is that someone actually cracks the code of the 3.0L PCM's and starts altering it to support 2 or 3 BAR MAP sensors, and larger injectors.

For the 3.0L equipped vehicles, this is one hellova catch-22 situation. I say do alot of research and go with what you are comfortable with.


I'm just using larger injectors at a lower base pressure to emulate the stock 19# injectors. Then using a FMU to raise the fuel pressure to allow more fuel when I'm in boost. Then, when money allows, I'm getting a SAFC or like to fine tune the setup for the best drivability I can get without going with a true stand-alone setup.


Just my $0.02,

Wink

[Ondonti]

Quote:

Originally Posted by mwinkle353 I think Chris is using a TEC3 unit on his newly acquired Custom-built 3.0L Nitros fed monster. But time will tell as to how well that system works. I think he's still breaking in the motor yet.

he is running haltech, tec 3 is electromotive. I wish I had $3000 for a tec 3

[Ondonti]

wink messing with the MAP wont do any good for our motor. SAFC works great when you have an MAS signal that can be increased, but the map signal cant go beyond what the computer understands. If the SAFC actually intercepted injector pulses and lengthened them that would work, I dont believe it does that.

The only thing you could use the safc would be for leaning out the injectors to maybe work on straightening your a/f. I think both Hassler and I have been able to get a very flat a/f line using rising rate regulators.

Still, the safc is worthless without wideband or dyno time. I have a buddy borrowing my wideband and laptop so he can tune the safc on his SR20 nissan (MAS engine).

[Turbo3.0]

Quote:

Originally Posted by Ondonti wink messing with the MAP wont do any good for our motor. SAFC works great when you have an MAS signal that can be increased, but the map signal cant go beyond what the computer understands. If the SAFC actually intercepted injector pulses and lengthened them that would work, I dont believe it does that. The only thing you could use the safc would be for leaning out the injectors to maybe work on straightening your a/f. I think both Hassler and I have been able to get a very flat a/f line using rising rate regulators. Still, the safc is worthless without wideband or dyno time. I have a buddy borrowing my wideband and laptop so he can tune the safc on his SR20 nissan (MAS engine).

Well if you use larger injectors and a 2-bar sensor, the S-AFC should work for fine for MAP signals. You can adjust the MAP signal for idle and low rpms so that the injector pulse width is smaller to compensate for the larger flow rates, and barely alter the signal in the higher rpms so the pulse width is still at it's max, but the higher fuel flow rates allow more fuel into the engine. So basically it won't help you with stock injectors, but should with larger ones.

I still don't recommend using it though. Even with wideband and dyno time, the s-afc was worthless and did next to nothing for my setup. I don't know if mine was defective, but it wasn't very helpful.

[Ondonti]

Im just instigating that you could use it to pull tiny amounts of fuel and clean up the a/f ratio. Not sure if that would screw up the spark advance though.

I would never use one of those pieces of crap though.

[Turbo3.0]

Quote:

I would never use one of those pieces of crap though.

I agree. Invest in some good stand alone engine management if you're planning on making a decent amount of power.

[mwinkle353]

That's why I was thinking of using one with the FMU. Set the coarse fuel enrichment a bit rich with the FMU and then fine tune the mix with the SAFC by reducing the MAP voltage.


But when I start making huge power, wich I'm not expecting to, I'll get a decent stand alone and make it a race car.



just my thoughts,

Wink

[Ondonti]

Quote:

Originally Posted by mwinkle353 That's why I was thinking of using one with the FMU. Set the coarse fuel enrichment a bit rich with the FMU and then fine tune the mix with the SAFC by reducing the MAP voltage. But when I start making huge power, wich I'm not expecting to, I'll get a decent stand alone and make it a race car. just my thoughts, Wink

This is what i suggest in my earlier post

[Harvii]

I used a Vortech Super FMU on my supercharged 3L. I'll be working on megasquirt fuel managment for the blower setup when the weather starts being nice out.

[Boogieman142]

i was thinking if using a t2 ecu and having it setup with 4 extra injectors like in the intake hose or something. I would have the power to it run off a switch so that as soon as there is a positive pressure in the intake it will turn on and fire the injectors. What does evertone think about that, yes, no, do u think it will work?

[irocelectric93]

What about that simple digital systems....? I know nothing about it...i know some guy used it in his DOHC 4 cylinder in a tona....and yeilded sweet results but i could be mistaken...fuel management sort of confuses me....