air filter for '93 LT1

[Injuneer]

Originally posted by N20LT4Bird
Injuneer, you could use the same arguement about the MAF system, that you used for the speed density. A MAF system uses that temperature info to calculate the "mass of air" entering the engine. When the heated wire is cooled from imcoming air, it will be cooled more if the air is cold (obviously). If the IAT is disabled, the PCM does not know whether the wire is cooled due to more air or just cooler air. Obviously it looks at TPS, RPM etc.. to determine this as well, but the IAT is just another piece of the puzzle. Leaving it out of a MAF system could disturb the fuel management. Obviously, Im not GM engineer, but I thought I would throw it out there.

But the MAF sensor uses its own "internal" air temperature sensor. It doesn't rely on the IAT sensor. If you look at the wiring to the MAF, there is only an output signal wire, and no "input" wire to feed it the IAT value. MAF output is a variable frequency that is converted to mass flow via the calibration table of "frequency" vs. "grams/second" in the PCM.

In later models, the IAT became so "redundant" that is has been deleted and incorporated into the one that is already in the MAF sensor. When you think about it, the LT1 IAT sensor is AFTER the MAF sensor, and would be reading the temperature of air that includes the small amount of air that has been heated by the wires.

The MAF need the inlet air temp, and then measures the power (Isquared x R) required to maintain the wires at a fixed number of degrees (e.g. 100degF) above the incoming air temp. Mass air flow (#/HR) = heat loss (BTU/HR) / [specific heat of the air (BTU/#/degF) X delta degrees (degF)].

[Jason97T/A]

Im still debating on whether to do this cheap mod or not. I don't want it to mess things up at WOT. Fred, have you ever heard anything "good" about this mod, or has it all been about losing hp at WOT? And Joe, did you notice any difference, good or bad, at WOT. Thanks
Jason

[Joe 1320]

Well, I've used it for 4 years and haven't messed up anything with it. As far as a WOT gain, doubtful. Like I alluded to before, it's a part throttle gain to restore the snappy feel of the throttle that seems to go away once the car gets up to operating temps.

[N20LT4Bird]

Injuneer, maybe you misunderstood, or I wrote it wrong?? I didnt mean to say that the MAF uses a direct reading from the IAT. Obviously this is not the case. But maybe the PCM uses the IAT info as part of its algarythym for determining the fuel curve. I dont know? I offered this up as an explanation for the loss of power you were talking about.

You seemed to allude to this in your last paragraph when you said the "MAF needs inlet air temp in order to maintain the heated wire at a fixed number of degrees above intake temp".

Also the IAT is before the MAF on my car. Its in the ram air box. Not that has anything to do with what I just said.

[Jason97T/A]

Originally posted by Joe 1320
Well, I've used it for 4 years and haven't messed up anything with it. As far as a WOT gain, doubtful. Like I alluded to before, it's a part throttle gain to restore the snappy feel of the throttle that seems to go away once the car gets up to operating temps.

Joe, i got to think bout it. You're probably right. SLP sells pretty much the same thing and they know their stuff when it comes to f-bodies. I dont think they would sell something that would hurt performance? I'll probably by a resistor tomorrow and give it a try.
Jason