Intake Air Temp

[jp4130]

Here is a quote from cobb I came across; it supports my previous gut feeling that the iat fix people have been using is not the best idea for these cars.


"I can imagine that some intakes can make this worse. There are a few hundred compensation tables throughout the ECU that function off intake air temps. Some of them are directly related to fuel and ignition timing and yes, we can alter them. However I don't think I'd recommend simply clamping the IAT signal. That can really throw a monkey wrench into all the compensations that you probably do want and need for IAT.

Cheers,
Trey @ COBB"

 

[dparm1984]

I don't know exactly what this IAT fix is, but I know that people sometimes stick resistors in-line with the IAT wiring to fool the ECU into thinking the intake air is not as warm/cold as it really is. BAD idea.

If you've ever looked at how complex the fuel tables are, you'd know that messing with things is not smart.

 

[jp4130]

I don't know exactly what this IAT fix is, but I know that people sometimes stick resistors in-line with the IAT wiring to fool the ECU into thinking the intake air is not as warm/cold as it really is. BAD idea.

If you've ever looked at how complex the fuel tables are, you'd know that messing with things is not smart.

(iagree)

 

[mrlilguy157]

this is why i don't think piggybacks and tricking the ECU is the best way of doing things.

 

[AutoXRacer]

(iagree)

I am one that does not like to mess with the ECU with cheesy MAP clamps, resistors, etc... I'd rather wait for a true tuning solution.

 

[///M Compact]

Exactly.

 

[tru-boost]

i agree about the IAT mod 100% and have said so from the get go. the map clamp i stand by 100% though. it does trick the ecu, but no harm comes from it. it simply stops, or at least reduces the amount of fuel cut. the car still has full control of fuel and timing and what not. even with the clamp my car will fuel cut under high boost in cold temps. that means the car still has the rest of its little nannies working for me.

 

[zoomzoomms3]

"The fact is that the MAP sensor also has a temperature sensor. Why?
Because the air temperature measured at the MAF changes after it flows
through the turbo, and then the temperature changes again once it flows
through the intercooler. So even though the air may have been only 50F at
the MAF, it may be 200 at the MAP sensor. Because we only care what the
temperature of the air going into the engine is, who gives a hoot what the
temperature is at the MAF sensor?! It's going to change anyway!

I don't want to imply that the MAF temperature sensor is useless, as it does
ensure an accurate reading. However, the change of a few degrees up or down isn't going to appreciably change the air/fuel mixture, as we've
demonstrated on local SPEED6's."