Thread: Is your IAT sensor hurting performance? Find out here!

There are tables in the PCM that calculate AFR and Power Enrichment due to intake air temperature.

The calculations between the IAT and the MAF along with the O2 sensor all three coincide with adjusting for the best fuel mixture. This is partially why a VE tune can be so productive, because you're basically helping the computer learn the density of the air, and then the MAF and IAT help it adjust on the fly.

Believe it or not, the PCM has a pretty decent idea on how much air is injested in the engine...but it takes 3 things to help it along.....the MAF is instant, the O2 readings are instant.....Wouldn't you think it would make sense for the IAT to be instant as well?

Originally Posted by Reptile

There are tables in the PCM that calculate AFR and Power Enrichment due to intake air temperature.

The calculations between the IAT and the MAF along with the O2 sensor all three coincide with adjusting for the best fuel mixture. This is partially why a VE tune can be so productive, because you're basically helping the computer learn the density of the air, and then the MAF and IAT help it adjust on the fly.

Believe it or not, the PCM has a pretty decent idea on how much air is injested in the engine...but it takes 3 things to help it along.....the MAF is instant, the O2 readings are instant.....Wouldn't you think it would make sense for the IAT to be instant as well?

Yes, and if you ever look, the PCM does not start pulling timing until IATs reach 122* with a Mg/cylinder pressure of 480 and up. THAT by itself is only -1.01* of timing. At 140* it goes to 1.49* of timing. I forsee only 2 scenarios for this.

1: Your in the staging lanes WAY too long with your engine running. Turn it off.

2: Its 95*+ outside. Dont expect to cut a PB anyway even if you do have all of your timing avaliable to you.

On a nice spring/fall day, this should not matter.

why do ya'll think the thermisters in the MAF are so small and delicate?
the IAT in the LQ4 maf reacted way faster than the OE unit on the whippled Riv