Air temp compensation with GM MAFT

[Newlogics]

Well, I'm seeing very different A/F ratios between night and day runs. I assume it is due to the fact that GM maf doesn't have air temp sensor. I am actually planning to wire the temp sensor from 1G maf, but I have a question:

Does compensation for different air temps accur at the MAF circuits or at the ECU level? Obviously, if stock MAF does the compensation on its own, then wiring the temp sensor into GM MAFT won't help. Does anyone have that info ?

Thank you.

 

[gixrman]

I was told by mike(ramchargers) that the temp. is set at 80 deg. and does not change. I have mine set up in blow though and have seen the air temp. on my pocketlogger show a lower temp. but never over 80. I know thats wrong, and differences in seasonal temps drasticlly affect my settings.

 

[98TsiAWD]

Get a Wideband O2, then nothign to worry about

 

[Newlogics]

Get a Wideband O2, then nothign to worry about

My wideband should be here soon, but it dosn't have much to do with the problem, which is colder air being denser, but not accounted for...

 

[98TsiAWD]

My wideband should be here soon, but it dosn't have much to do with the problem, which is colder air being denser, but not accounted for...

Tune while the air in dense. You will run slightly rich in the daytime, but you just have to live with it.

 

[98spyderboost]

This is the perfect instance in which you guys leave me. I am about to go with the gm MAFT setup. What does the "blow through" setup do and why would this effect the air temp readings.

Also if you have a GM MAFT setup then why would you need a temp sensor. Doesnt the MAFT detect air throughput or "denisity?" Therefor effectively eliminating your issue with temp all together? MY TPI 383 ran better in the winter. Same amount of air VOLUME but different density due to the colder air. The ECU compensated and bingo-bango, it pushed more fuel equaling more power.
If my reasoning were accurate then your ride should be doing exactly as you are talking about... I dont see how a temp sensor would help.

BTW when ppl say wideband... is that just "An accurate a/f meter that has to have a special sensor", or does it interface with your ECU?

 

[98spydert]

Yes a wideband is a much more efficiant a/f monitor requiring a more accurate (and expesive) sensor. The systems are stand alone in most cases also with their own read out and logging software.

The stock MAF measures air by volume then the ecu determines the density of that air by the temperature. The GM MAF measures the density and volume through the hot-wire method so no seperate temp reading is needed.

When air is compressed, the temperature is raised. There for the temperature is different at the air filter and after the turbo, as is the density of the charge which is what matters in the end equation. After the turbo, the air is then cooled by the intercooler so you have 3 different temperatures/density. The only temperature/density that matters to the ecu is that of the air moving into the engine for determining the amount of fuel to add. The most efficient way to get that number without moving to a stand alone system is to use the GM MAF sensor as close to the throttle body as possible, or as it's called "blow-thru."