the sensor that plugs into the intake elbow right before the throttle body, is that the sensor that retards or advances timing????


if so have people moved it to the airbox before to advance the timing a little????

if so (forgive me) but what exactly would be the benefits of advancing the timing????

i just wanna do a few little extra things before i head to thunder (waiting for money) for a tune with the spray and a few other goodies i am planning on putting on.


if i am at all headed somewhere or if i just dont know what the hell im saying then someone please correct me or tell me exactly what im thinking.


Thanks guys, Scott

 

I believe thats the Inlet Air Temperature sensor,They say relocating it to further away tells the computer that the incoming air is cooler and therefore,it adds more gas to the air/fuel ratio to increase performace.Some say it destroys catalytic converters because of extra gas.

 

well i dont have cats..............so hmmmmmmm

 

anyone else have any input on the subject?????

 

You might be talking about the opti vent tube. Is it the one with the blue cap on it?

 

no, not that one..............when looking at the engine..........the intake tube comes off the throttle body and turns to the right to go down to the filter...........well its in the elbow, on the outside of the bend.

know where im talkin about now??? (if not i will take pictures)

 

That is the inlet air temp sensor. In a mass air setup (94-97) is it not used to calculate the air flow to the engine, so it will not affect the A/F ratio. It will not lead to overly rich A/F ratio, and it will not hurt your catalytic converter. In the 93 speed-density cars, this is not the case. The PCM uses the IAT value to calculate the mass air flow, so that lowering the IAT sensor reading would increase the calculated mass flow, and cause the PCM to add extra fuel.

What it "APPEARS" to affect is ignition timing. There are a few degrees of spark advance (usually about 3*) that show up in the spark timing set by the PCM, that can not be found in the known timing tables (spark advance vs. MAP and RPM). It is believed that there is a table hidden in the PCM that adjusts igntion timing slightly based on the IAT sensor temperature (maybe someone has found the table by now... I know a couple of years ago, no one could find it). It is well known that increased inlet air temperatures will increase the risk of detonation, so it is reasonable to assume that the stock programming would pull timing if the inlet air temp got too high. (I have programmed exactly that feature into my aftermarket engine management computer).

The stock IAT sensor location is subject to "heat soak". The under hood heat will cause the sensor itself to heat up, and give artificially high inlet air temps, possibly causing the PCM to reduce the spark advance. By moving the IAT sensor away from the engine heat, it gives the PCM a more accurate inlet air temperature.

Within reasonable limits, more spark advance increases power. So, you want as much as you can get (within reason - too much can actually hurt you), and don't want to give up 3* of advance just because the IAT sensor is heat soaked.

 

so hmmmmmmmmm............what would you suggest i do???? move it or leave it????

 

....I pulled my sensor out, pluged the hole in the air intake tube where it
went and put a resistor between the wires. The good news is that my car
will never get the timing retarted for no reason. The bad news is that if there
is a good reason for my timing to be pulled back it won't happen so it could
blow up. I live on the California coast so I'm not really concerned about my air
inlet temperature getting to hot {plus I sometimes do things that aren't so smart . If I lived in the Nevada desert I would be {not smart, just concerned about my air intake temperature . The sensor retarts the timing when the air inlet temperature gets hot so that it won't ping {pre-ignite, detonate}. So doing it is not really safe. Like Injuneer said "I have programed exactally that feature into my aftermarket engine managment computer". If your putting nitrous on your car this free mod isn't going to make a whole lot of difference!!!
But, anyway if you do it there are pictures and instructions on the board. I don't remember what ohm resistor to use but you get 'em at The Radio Shack 5 for 99 cents..... Bill

 

The resistor is 4.7kohms (=57*F). But there have been some dyno pulls done by people comparing the resistor to stock, and they lost HP. Why? Who knows. I think (and this goes back at least 5 years) it was a group from Georgia F-Body members who had several people try the mod during a "dyno day", and got the negative results.

You are ALWAYS better off giving the PCM the correct into, and not trying to jury rig it with band-aids. If there's a way to improve perfromance, do it with tuning, not with a resistor.

When my setup was mostly stock with a lot of bolt-ons, I moved the IAT sensor to the metal cap of the K&N filter on my Honker CAI. Where before the move, the IAT might indicate as high as 140*F when the car was in stop-and-go traffic, the relocated sensor seemed to read within 5*F of the true air temp.

 

no no no no, i dont want to eliminate the sensor all-together i am just contemplating relocating it to the air box for a more accurate reading.

now what are the pros and cons to doing this??? would it make a difference or would it just be a waste of my time to do so??? does it make the car run more efficiently or what happens when it is put down there???


OR is it located behind the MAF for a reason?????

thanks guys, Scott