I've been chatting about a Vortech Supercharger and not using an FMU. People have said to switch to a Syclone ECM and use $58 Code and I should be able to. My car is an 89 with a MAF sensor not MAP. Can this be done? I'm comfortable doing any re-wiring etc. Would I have to change the PROM as well? Any help?

 

Do some searches on 749 ecm and $58 code on this site and on the net and you will find your answers.

 

Yup.... what he said. BW

 

The FMU is only part of the problem.

What's really at issue is how the engine breaths when in boost, and calibrating the fuel to correspond to that change.

In N/A mode, the cylinder is filled due to a vacuum beig formed and the engine having to work to draw the air in. The instant your in boost, that all changes, so rather then working to fill the cylinder, boost is actually pushing the piston down. It makes for a sudden an serious change in VE. While a N/A might be good to get to 95% VE for a street engine, a boosted motor can easily get to 120%. And that last 20% is just in boost. And to get the motor happy, means adding the fuel when it does that most good. With a MAF system there is just no way to get the calibration to see boost, using the MAF. Well, you could but you'd have to rewrite alot of the code to do it.

If you want to stay with the MAF then I'd suggest you go to the GNTtype site, and closely look thru the Hac there, on how GM used MAF with a boosted application. BTW, IMO, it wasn't pretty.

 

Do you guy's feel that it's worth the work? I have seen posts where people use FMU's and their cars run fine. I would like to make the most I can, but if it's more trouble than it's worth??? Any opinions?

 

If you want to keep your MAF and run a FMU, seek out Willie on the power adder board. He has a hot supercharged TPI with MAF and a FMU.

However....

IMHO, a FMU is a band aid approach, where running $58 and a 749 lets you control the fuel via the ECM, rather than a rising rate mechanical device.

Its a matter of preference.

BW

 

It is worth the work, but be prepared to be stumped a few times and the actual rewiring is the easy part. Also beware injector sizing is very crucial on the bottom end and top end. To big will make your car nearly undrivable in closed throttle conditions, and to small will give you a one way trip to engine rebuild land if your not cautious. The thing I really like about the 749 conversion is it is simple with no extra added hardware to fail.

 

It's worth the work.
IMO.
If it was a cheaper, better answer, then GN would be using it in there T/C and S/C applications. Or Ford, or Volvo, or Porsche, or any other oem. As far as I can see, it's just the aftermaketeers trying to keep prices down that go that route, since in theory they don't have to hac the ecm to get it right.

 

I ran a Cartech adj. FMU on my car for about 6 mo. until I swapped out to the 749. I have never looked back since. Fueling was damn close with minimal tuning. If your up for some repinning I would jump on it.

 

the 749 swap is great. its beter then 90% of the aftermaret junk out there and butt loads cheap. an FMU is really a bandiad. no ifs ands or buts about it.

 

Ditch the MAF. Convert to the 749. You never really know what you're getting with a FMU unless you have access to a dynojet. I'm running a FMU right now on my blown 91 Z and I'm convinced the only reason it works is because my motor is mostly stock. As soon as I get radical with the motor, the FMU will get further and further from a perfect tune. The 749 allows you complete control. You know exactly whats going on. Its the cheap OEM equivalent of expensive aftermarket DFI setups like F.A.S.T., Accell, etc. The real question you need to ask is if you're willing to get into tuning. Its pretty weird when you're first learning (I'm still at this stage) but I guess it gets easier when you get the hang of it. The last thing you want is to do the swap but then get frusturated tuning and the car runs worse than it did before the swap.

 

Willie still uses a three injetor "Superfueler" the last I saw. He does produce results either way.

 

Thanks everyone for the input. I'm working on the supercharger right now and I'm sure I'll have a lot more questions. Thanks again!

 

I have been relatively successful running the Superfueler:

http://www.carrollsupercharging.com

But things have changed recently. With my new "bulletproofed" 305, my plans include a LOT more boost, on the order of 20+ pounds and have decided to make the switch. I'm ditching the 165 (MAF) and Superfueler. I will be using the 749 with a 3-bar MAP.

 

Does this code and ecm retard timing with the boost?

Heres what i am going to build.

3.4l 3400 hybrid with a .60 .63 t04e turbo.
And i want to be able to adjust the fuel and the timing. I am debating either a ecm swap with the best suiting code. Or the latest megasquirt.
What ecm and what code shoudl i go with.

 

You have a few options.

One is to go with a '7727 (under hood type ECM), or '7730 (underdash style), and use TGP code, there are a few hacks for this, including 3 speed auto, 5-speed manual, and WBO2 configurations. The bins and masks are based on $8F.
There are a number of people using this on thier forced induction genII, genIII and hybrid 660s, with great success.

Another option, is to use a '7749 and $58, as suggested above in this thread. I'm not sure how close this will be to use, for your application, but should be a good starting point. I also know this base bin has been quite hacked for various reasons.

The option that I will be using is this combination:
'7730 or '7749 (possibly a '7727, but that's untested as yet), and code 59 ( www.code59.org ), this code is based on $58, but has been cut apart, put back together, expanded and is still being developed, to do just about anything you can think of.

 

The $58 and $59 code will run in any of the three ECMs ('7727, '7730, '7749).

The $8F code will run in either the '7727 or '7730. I don't know if it will run in the '7749.

The '7727 & '7730 are the same with the exception of the external form factor (case & connectors).

The '7749 has an additional injector driver and one less quad driver. It has the same form factor as the '7730.

It is the one less quad driver in the '7749 that can cause issues. This is why when running the $8D code ('90 - '92 TPI) in a '7749 the TCC output is lost. It uses the quad driver that doesn't exist in the '7749. Where the '7727 & '7730 have that driver.

RBob.