Speed Density vs. MAF system?
Doesn't it relate more to the available MAFs' limit
of sane output - 12kHz and roughly 450 gm/sec of
mass airflow? A desceeened MAF may present a
fractional inch-H2O pressure drop but once it output
quits making sense it's just baggage (or worse). You
might could fool the PCM to skirt the 511 gm/sec
code limits but there aren't (m)any commonly available
MAFs that will even get you there without clipping.
Now, on a relatively-unmolested A4 I seem to be pulling
a max frequency of 10.2kHz (vs 12K truck MAF, 11250 PCM
table limit) and this corresponds to 308 gm/sec against the
439gm/sec stock table limits. So a stocker has room to
grow roughly 50% in power output (going by MAF "utilization")
before MAF programming even needs to happen? Now while I
see people saing the stock MAF can "support" 600HP that
seems a bit optimistic. 450HP seems to be close to the edge
and by 500HP you might be having to use a fake lower gm/sec
scaling to stay off the 511 limit and also scale injectors to match?
of sane output - 12kHz and roughly 450 gm/sec of
mass airflow? A desceeened MAF may present a
fractional inch-H2O pressure drop but once it output
quits making sense it's just baggage (or worse). You
might could fool the PCM to skirt the 511 gm/sec
code limits but there aren't (m)any commonly available
MAFs that will even get you there without clipping.
Now, on a relatively-unmolested A4 I seem to be pulling
a max frequency of 10.2kHz (vs 12K truck MAF, 11250 PCM
table limit) and this corresponds to 308 gm/sec against the
439gm/sec stock table limits. So a stocker has room to
grow roughly 50% in power output (going by MAF "utilization")
before MAF programming even needs to happen? Now while I
see people saing the stock MAF can "support" 600HP that
seems a bit optimistic. 450HP seems to be close to the edge
and by 500HP you might be having to use a fake lower gm/sec
scaling to stay off the 511 limit and also scale injectors to match?
