MAF GM systems

[Frederic Breitwieser]

Aloha MV,

> if you have big cubes and twin turbos, could you put one MAF
> sensor on each turbo, have the turbos totally separate, say,
> each turbo pumping into the opposite bank from what's driving
> it, and make the ECM reference only one of the MAF sensors?

I had tried that actually on the Buick V6... I needed two MAF sensors simply
because the twin turbos flowed more than one MAF was going to tolerate, so I
split it like you had suggested.  Didn't really work well, especially at idle
to 3k RPM range.  Ran rough as hell.  I attempted to create a little circuit
to combine the MAF frequencies, summing them, then generating a new
frequency.  Eeeeeh, didn't work either, didn't start at all.  At least with
the OEM ECM.  I was trying to lie to it :)  With aftermarket stuff it might
be much easier.  Just move all the fuel tables up!

> Since the other side of the engine is the same displacement
> and (hopefully) running at the same speed, you could base

One would hope!

> your calcs on *half* the actual air flow, no?

Makes sense....

> Actually, it is to provide the identical restrition to the *real*
> unit on the other side of the engine.

That makes sense also.  I would suggest not to bother trying to merge the
signals - didn't work well for me. Though the GM parts I used ouput a
frequency rather than a voltage, so it was more complex than it needed to be.



> for high volume applications... What is on the Hummer?

Two edelbrock throttle bodies and a haltech EFI system.  10lbs of boost, no
more.  No OEM ECM :)

--

Frederic Breitwieser
Bridgeport CT 06606

1993 Supercharged Lincoln Continental
1989 HWMMV w/turbocharged 500cid Caddy
1975 Dodge D200 Club Cab soon to have 431 stroker + turbos
2000 (I hope) Buick GTP (Mid-Engined Sports Car)