Quote:
Originally Posted by apk919
I don't have a definitive answer, but I'm leaning towards IAT being pre-SC. Maybe an engine expert can chime in (paging charliex...). Even though there's some correlation, it seems that changes in IAT are related to engine temperature (which is correlated to RPM/Load also) and not charge temperature. I don't see IAT being higher than the post SC/pre IC data in the graph below (from your session3). There's been some discussion of how the throttle body gets heated by some of the emissions gear, which can cause IAT to rise higher than ambient, and be related to engine load.
The pinouts you're referring to are just two pins from the TMAF... and yes, TMAF stands for Temperature/Mass Air Flow sensor (it senses both).
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yes the cylinder head gases are routed to the throttle body location. But these temps must be in the 100C's. (more reason to install a vent to atmosphere oil catch tank)
The MAF is before the TB, on the airbox, so is that to say the TMAF is not located behind the throttle body then? If not, then this temp sensor should be getting hit with only ambient air. I'd think the ecu would want to take IAT temp post SC because this is the charge right before combustion, so seems counterintuitive. hmmm...
on your graph, whats the yellow temp? if it's downstream and it's not the "TMAP IAT" location on the exit side of IC, did you put a probe here?
nice job on plotting the graph, thanks for doing that.
Oh... note checked multiple times with an infrared gun pointed at IAT location (at idle), and it matches the IAT reading. But this could just be a coincidence.