AIT resistor

[beachknight]

[:I]Hey all. New to this forum. been reading it for a while getting ideas for my '05 GT Convert. Love the car. Will get some pics up soon. I recently bought a Air Inlet Temp sensor resistor that fools the computer to think its getting 71 degree air at all times at WOT. Seem to have gave a little HP boost while in WOT. No check engine lights on or anything. Anyone else ever tired one of these[?]

[CREWZIN]

A lot of owners have bought that little gizmo, and it should work. It's like getting that "little extra" in the morning when the engines cold. But where does it say it's only working at WOT? The one thing you have to understand it that the computer is always thinking the incoming air is colder than it actually is so it's ALWAYS dumping more fuel into the engine...even at idle. With the mileage most of us are getting, dropping another couple miles per gallon isn't worth the 2-3 extra hp that you get.

[beachknight]

From what I understand of the PT's computer is that it get its input for fuel air mix from the MAS and O2 sensors at 'regular' throttle positions and at WOT is goes into a bypass or loop mode and only takes the AIT for the mixture. Of course I have been known to be wrong from time to time.[^]

[Mean Green]

Has been recommended not to use this mod on non turbo and turbo PT's, especially for a measely 2-3 hp by an ASE Certified Mech. If you want to know what to do to up the hp and tq then ask. I had a 270 hp '03 GT that ate V8's for lunch. [8)]

[Black_GT]

quote:Originally posted by beachknight

From what I understand of the PT's computer is that it get its input for fuel air mix from the MAS and O2 sensors at 'regular' throttle positions and at WOT is goes into a bypass or loop mode and only takes the AIT for the mixture. Of course I have been known to be wrong from time to time.[^]

The PT's are a MAP based system. And yes, the computer runs in closed loop most of the time. When you hit WOT and it goes to open loop, it refers to a lookup table stored within the computer itself. It also hits open loop on initial starup and when decelerating for more than a few seconds with 0 throttle input. Anywho, this is a simple mod, the exact value of the resistor you need is 10k, 1/4 (read .25)watt resistor. make sure you get this one - a different value will mess things up a bit. (They're like 10 cents at Radio Shack) What it does is to fool the PCM into thinking it's slightly cooler than ambient, and to advance the timing 1-2 degrees. Good for a few horses on a warm day. I still wouldn't advocate it's use. It's fooling the computer into thinking it's colder outside air coming in, advancing the timing and feeding more fuel for the advanced timing...ALL THE TIME. Even at idle and when your roaming around in traffic it's throwing more fuel to get burned up when you really don't need it, so be prepared to lose 1-2 MPG. Oh, and on a cool day it's useless.

[MX-5]

2 problems.

The PCM goes open loop anytime above 85% throttle.
The IAT sensor you're trying to fool isn't even used above 85% throttle.

Below 85%, you can tell the PCM it's colder, but the O2 sensors have total control. The IAT will say to dump more fuel, but the O2 sensors will back off long & short term fuel trim to keep the air/fuel mixture 14:1.

Just leave it alone.

[purple04]

I agree, it's the computer equivalent of snake oil. You are taking the word of a person who is trying to sell you something over the word of the people who designed, built, sold and warranty your car. Will it help? maybe a little. Do you check your tire pressure every week? That may help a little, too.

[thegoldpt]

Yeah but the smog test...........????