Gas mileage and headers

[Bruce Plecan]

> That's the thing that's driving me crazy!!!  I would expect more pedal
input
> to show up as more TPS voltage (at the same rpm and gearing) or as higher
> MAF reading or more fuel shown as a higher BLM.  But it doesn't.

The total difference in Air Flow from idle to WOT is like 200 or so grams
sec, and you want to see 2-3 at 30?.
The MAFs and the early ones especially just aren't that accurate, IMO.
I've been doning some tinker lately with early and late MAFs, with a
translator, and the new one is just so mor responsive, that you have to
dampen the tables slightly cause it responds so much quicker.

The block
> learn multipler is lower, the reported pulsewidth is the same, the MAF
> reading is the same.  (Of course, by "same" I mean there is some high
> frequency variation between Diacom frames but they are generally averaging
> about the same.)

Ahh, remember there is alot of filtering going on, and YEP it's all
AVERAGES.   Trouble is some are weighted heavier.

  Back a couple of months ago when I was doing minor chip
> tuning for the highway I was bumping up the timing in individual cells and
> could see the BLM, MAF reading, and pulsewidth go down for the same rpm
and
> cruise speed.  Now, the only Diacom parameter that changed is IAC counts
> went up 10, and coolant and intake air temps went down 5 to 10degF.  I
> mentioned the timing change previously.  Maybe that's it.  Seems
> counter-intuitive to me, but I'm probably just thinking too hard.  I'll
keep
> working on it.

You don't have to do any thinking about it, just do what works..
Experiment.
Bruce
    Still looking for adult suervision.
    Little guys finally got the War Paint off, and are now on a letter
writting campaign.  So far 326 letters today, and 658 words of text.
They're not long on explainations!...
>
> Thanks again for tolerating the out-loud thinking!
> Steve
>
> >As far as the mpg going down after header install, it could be the oxy
> >fuel, or it just could be the fact that you torque curve has been
shifted.
> >Depending on the design of the header, you can lose bottom end torque,
and
> >with OD at highway speeds, your operating in that range.  Less torque
> >requires more pedal input and more gas.
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