maf curve points

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lugbolt
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maf curve points

Post by lugbolt » Mon Jul 29, 2019 2:57 pm

'92 Mustang, bought it as a project. 427w swapped, A9P. It runs but I'm messing with it. Using binary editor and QH. Since I bought it not knowing anything about it, I sent the MAF off to Pro-M and had them flow it. They sent it back with a 37 point curve. BE only allows 30 points. What shall one do? Skip a few at the top end of the chart or?

jsa
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Re: maf curve points

Post by jsa » Mon Jul 29, 2019 4:52 pm

If the engine operates in the bottom part of the MAF range, that would work. The top entry must be 16v though.

Optionally drop one out every so often.
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John

95 Escort RS Cosworth - GHAJ0 / ANTI on a COSY box code
Moates QH & BE
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Chucko
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Re: maf curve points

Post by Chucko » Mon Jul 29, 2019 10:50 pm

Take the top point on their curve and duplicate it at 16V.

Then you can pretty much lop off anything below 20 kg/hr at the low end - your 427 will never get that low except during cranking, when the MAF is ignored anyway.

If it's anything like my 37 point curve, some points will be much closer together. You can drop any that seem redundant.

What was the top number on the chart BTW?
'89 LX 5.0, Crane 2040, Pro-M 75mm Bullet, 65 mm TB, ported stock intake & E7TE heads, 24 lb injs., JBA shortys, cat X-pipe, A3M1 (GUFB strategy) w/Moates Quarterhorse, BE & EA, close ratio T5Z, 3.55 rear

Chucko
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Re: maf curve points

Post by Chucko » Mon Jul 29, 2019 10:56 pm

OBTW my rough calculations say if that thing will rev to 6000, you're looking at roughly 1540 kg/hr at 100% VE (load). So don't cut off the top of the curve!
'89 LX 5.0, Crane 2040, Pro-M 75mm Bullet, 65 mm TB, ported stock intake & E7TE heads, 24 lb injs., JBA shortys, cat X-pipe, A3M1 (GUFB strategy) w/Moates Quarterhorse, BE & EA, close ratio T5Z, 3.55 rear

lugbolt
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Re: maf curve points

Post by lugbolt » Wed Jul 31, 2019 10:41 pm

The more I thought about it, you're right. But then I got to thinking, what is inside the engine? The builder died midway through the build but I nicely asked his wife if she knew of anything about the engine. Well she was cleaning some stuff out and I got all of the stuff she could find including a full build sheet of the engine, cam and all.

So what I found out was that it's a 408. FTI cam, shows 238-248 at .050" and 111 LSA, lift 612/609. Hydraulic roller. Guy did a good job on the build; Mahle pistons, 10.6:1, AFR205. T56 Magnum too. It should run well.

Yeah I don't think it'd be a good idea to lop the top numbers off. I think the top of the curve was 1629 Kg/hr. I seen reference in another thread about knocking off 2, 4, 6, 8, and 10 I think. Tried that, entered the FMS green giant injector data, and I gotta floor it to get it started and when it does start, it's plug-fouling rich. Shut 'er down and went back to the 19lb stock A9P data and it runs "better" but I still have lots of work to do--and quite a bit of studying up on it. As of right now it needs a set of plugs. I initially put the headers on and transmission in over the winter, got sick, got busy, etc and finally got a chance to fire it up to find that it was PIG fat, period, on the stock tune. Found #3 injector stuck open. Replaced it and it really hasn't been right but that could be a million things which I'm slowly sorting through.

Ya know what? I don't remember if I corrected the injector data from lb/m to lb/s. I'll have to look into that. At this point all I want to do is get it close enough to not wash the bores down and probably pay someone to do the dyno tuning on it. I don't want to daily drive it, but I do want it to be something I can ride around in from time to time. Oh yeah, a/c works great now too. May get a little time this weekend to mess with it.

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