I have brought this up several times on other forums (may be this one) but why would you want the air fuel ratio richer? Has anyone measured the A/F during part throttle loads. I have seen that at WOT the mix is too rich in stock trim. (as seen from my dyno runs and others that measured the exhaust gases with a wide band o2 sensor) I also know that opening up the intake has little effect on the A/F ratio again at WOT. The only thing that seems to lean the Hemi out was headers. I base that on the dyno sheet posted from the Dynatech header results.
Now I'm also assuming that the computer will adjust the A/F at part throttle because of the o2 sensor inputs. So the actual move of the inlet temperature sensor should only cause an effect for a short period of time.
All theory, anyone have some facts or measurements either way?
I believe you're right on all accounts. I have not seen anyones' dyno runs (including yours) that has had the correct mixture for maximum performance (around 12.5-13:1). All have been on the rich side (11-12:1), which I am sure is by design to save engines. You're also correct about the computer controlling the mixture with input from the 02 sensors during part throttle conditions. Moving the IAT sensor would only make the rich condition worse at WOT, but wouldn't have any effect on part throttle operation. Instead of trying to "trick" the IAT, why not just use a GOOD cool air kit that really delivers colder air. Power increase from cooler, denser, air is about 1 % for every 11 degree reduction in intake temp. Pretty inexpensive power gain IMO. I did want to ask you where they put the "sniffer" when they took your mixture readings? I've read somewhere (I'll try to find ref.) that if readings are taken after o2 sensors and cats...i.e. tailpipe, the readings are not always accurate. Here's a quote from an article about the importance of the O2 sensors, in particular, the wide band type in our vehicles:
"a wide-band sensor has an output voltage which is directly proportional to the oxygen content of the exhaust. Put another way, the exact air/fuel ratio is known at other points besides stoichiometric. That's great news to guys who want to tune their engines for max power, since max power usually occurs when the air/fuel ratio is around 12.5:1, not 14.7:1, which is stoichiometric."
One thing I did find on the mixture is:
"In a closed loop emmissions system the oxygen sensor returns rich-lean information to the vehicle computer, by nature the oxygen sensor is always a little behind real time. If the O2 sensor is far down the exhaust pipe the sensor is placed further behind." So, this tells me if you're taking a reading at the tailpipe the readings will lag considerably from true readings, if taken before the cats." "Older style AFR meters relied on the Co or Hc content to determine the Air / Fuel Ratio, and if those AFR meters are used on modern vehicles after the catalytic converter, they will display incorrect Air / Fuel Ratio readings."