Engine IAT sensor mod...

IAT sensor mod...

So, the IAT sensor mod (adding a resistor) and the same mod to the ECT sensor, which in essence causes the engine to run rich and advance timing some....is basically crap we all know this. The ECU is smart and eventually figures it out and undoes your mod...not to mention all the problems from a rich mixture.

HOWEVER, has anyone considered using a potentiometer on the ECT or IAT sensors? That way, in effect, you could just turn the mod off whenever you wanted. It is proven that it DOES yield a couple HP at first. I might even consider a CAI or SRI if it would richen my mixture up some.

What you all think?

Late,
Trav

Is the mod cheap? And you can take it off anything you like right? If it is, go ahead and tell us the result. It won't hurt much anyway.

Well, you get more power to either side of the 14.7:1 ratio, which is just the best for catalyst efficiency. Around 12.0:1 is best for power, but around 15-16:1 gives more power also because of a hotter and quicker combustion (hence some CAI's and SRI's give such good power boosts). But then again, running a leaner mixture under heavy acceleration is asking for LOTS of trouble.

Also gotta remember, the ECU advances timing on a cold engine - that helps too with this mod.

I thought a leaner mixture made more power than a richer mixture..

If I hit WOT with my nitrous system armed and the bottle closed, it just gets a kick of extra fuel...and it definitely doesn't help.

Intakes give you gains by adding more air into your engine. The ECU compensates for the extra air because the MAF reads more air entering the manifold, so the injector duty increases to compensate. I've never heard of an engine getting more power when it runs rich (don't have time for a physics lessen) but if you have some proof, I'm all ears!

Well, school me.

I have no proof, per se, but everything I've ever read indicates that the BEST a/f ratio for power is somewhere in the neighborhood of 12-13:1. I do know that running a/f ratios leaner than 14.7:1 will increase power as well, but not as greatly as a rich mixture. That's all not to mention that extra fuel is erring on the side of caution since a lean mixture can be disastrous to an engine.

I also understand that THEORETICALLY, an intake increases air flow and SHOULD increase injector duty cycle via MAF sensor readings, however it doesn't always work that way. When you go to messing with intake systems, the MAF sensor readings become inaccurate, unless the intake is VERY well designed (I have never saw one that is), hence it doesn't give the ECU an accurate representation of the mass of air entering the combustion chambers. And in my particular case, with the AEM CAI, it left me with a lean mixture and lots of lean detonation.

Late,
Trav