"So what is being claimed here is AFR (air/fuel ratio) tuning is not important? Well folks, looks like another case of Loren trolling the forums to spam for business."
Another one that didn't fully read and understand what was posted. It was stated
that once the AFRs are within 1-2 points of the ideal of 12.6 (that's 10.6 to 14.6)
little to NO improvement in torque results and this was demonstrated in the the
second graph. Many claims to the contrary have been made over the years without
any supporting data. Well, now graphical data from a dyno run exists which indicates
the marginal effect of tweaking AFRs as compared to 'pushing' the timing. These data
have been lacking to refute the AFR tuning claims.
"Why doesn’t he disclose what kind of car this is, what are the modifications, and who was doing the tuning and how? Have you ever been to a dyno in your life? "
Again, it was stated that the car was a 911 3.2 and I was on the dyno making live
ignition and fuel map tweaks using an emulator to generate the map changes.
This was a simple tuning effort, that any high school auto shop student could do,
give the tools, as is the case for most tuning efforts these days. The goal of the
dyno tests was to determine the independent effects tweaking the ignition WOT
map and then separately tweaking the WOT fuel map.
The data presented basically corroborate what has been widely known and accepted
by those that have basic engine knowledge indicating that 'pushing' the ignition
timing once the AFRs are within a few points of the idea has the most significant
effect compared to tweaking the AFRs. This becomes apparent when one views
the standard graph of torque versus Lambda shown here:
Graphs
Bottom line: For the typical stock factory engine which in all cases has AFRs
close to the ideal, no significant improvements result for AFR tweaks versus
'pushing' the ignition timing and that's the essence of what the so-called
performance chip really does. It's that simple!