O2 Sensor Tweaking...and MAF Enlarging...

[Kurek, Larry]

Guys:

There is a major debate going on the F-body lists concerning HP gains from
"porting" the stock MAF. I am arguing that the HP gains being shown on the
dyno (7-10hp), are the result of lean out since the MAF is now out of
calibration and NOT due to the increased airflow. I think the stock MAF
flows around 650-700CFM, which on a NA 350 is MORE than adequate. Also, what
I am arguing, and has been proven by a few list members, is that this gain
is short term, since the PCM will 'relearn" the correct fuel trim values
from the O2 feedback, and adjust the mixture accordingly. So, any leanout
effect will be compensated for by additional fuel and you will be back to
zero gain. One list member has argued that any effect of this learning will
not be applied at WOT since the computer is not in learn mode. Doesn't the
PCM just use the last value in the BLM to adjust WOT fuel? Don't you need to
force this BLM cell to 128 (with custom programming) when going WOT to
negate any learning effect?

Finally, and this is my major question to this list. Has anyone ever
considered, or actually built, a voltage adder/subtracter for "massaging" of
the O2 signal? From what I can tell, this is the ONLY way to seriously
impact fuel curves (short of reprogramming) over the long term AND at WOT.
I'm sure you could build something that takes an input voltage and adds or
subtracts, say 0-100mv, and send this signal to the PCM. A nice dial setup
(adjustable pot) could vary the range (I would assume a +/- 100mv range
would work), and have the ability to synchronize two inputs (for a
left/right O2 setup) with the one dial. Doable? If so, how? comments?

TTYL!

Larry