Put the resistor on your air intake....

[nikon]

Ok well you all prolly know what im talking about...putting a 4.7k 1/2 Ohm resistor on your air temp module thingy by your airbox, I did it, cost me a buck for like 6 and I noticed a differance but remember it makes your car think your suckin in 57 degree air...so anything colder and it would hurt ya...dunno...I like it..

[Shadly]

I'm confused. How does this help? I've heard it done and know it's easy, but why would you trick your PCM like that? It won't be able to make A/F ratio corrections as the temp actually changes.

[4thgenowner]

It's a waste of money. I tried it and my car ran rich like a mofo, or was it lean.. Whatever it means to burn more gas than air. It just used more gas, don't think the pcm got the a/f ratio right.

[99Camaro99]

it's call the Intake Air Temperature Sensor or the !IAT mod. It doesn't really do much unless you're at full-throttle. I only did it because I was given the extra resistor for free from another friend. JUST WHATEVER YOU DO...DON'T SPRAY WITH THAT RESISTOR IN...EVER!!!

[strange_trp]

tricks the pcm into thinking the ambient air is colder than it actually is. the point is to increase ignition timing advance, not to alter fuel delivery.
some people like the mod, some have had poor results or no change at all.
i know the iat module that slp sells sends a constant 35degf signal to pcm. not sure about the 4.7 kohm resistor. use the chart in haynes to see what 4.7 kohms should give you...
at any rate, even at WOT, the IAT sensor input has little influence on the pcm's calculation of proper fuel injector pulse width.

[99Camaro99]

the resistor reads the air as 57F

[strange_trp]

must be different from the slp version then because im looking at 35degf on autoxray right now. tonight when i get some time i'll chech resistance of the slp and post for those who are interested... or if someone wants to do this in the meantime....
actually according to GM's spec chart for negative temp coefficient thermistors (IAT, ECT) a resistor of 1.459 kohms should give pcm 104degf. 5.670 kohms should give you about 50degf, and 9.420 should give you around 35degf.
to account for what the pcm sees, you must account for additional resistance in the circuit to/fr pcm.

[Seppo Kaitainen]

It supposity works in hot weather. But how often is is 35deg w/ 80% humity? The pcm makes proper adjustments via the weather. Is 2 hp worth tricking the pcm to make the wrong adjustments?

God only knows what ill affects it has.

[strange_trp]

<blockquote>quote:</font><hr>Originally posted by Seppo Kaitainen:
It supposity works in hot weather. But how often is is 35deg w/ 80% humity? The pcm makes proper adjustments via the weather. Is 2 hp worth tricking the pcm to make the wrong adjustments?
God only knows what ill affects it has.<hr></blockquote>

pcm gets humidity info (to calculate air mass) from MAF sensor not IAT sensor.
2HP is mfgr claim, i would not say i gained 2hp from the mod. i would say i gained nothing from the mod.
the idea is to advance ign timing a few degrees by making pcm think incoming air is colder than it really is. and it does this. but the pcm will automatically advance at WOT until the point of detonation, because it sees the driver wants maximum performance. plus the MAF information given to the pcm somewhat contradicts the IAT information if you're using the mod, and the pcm will rely on MAF info much more often than the IAT for both a:f mixture at WOT as well as ignition advance.

plus, 2 degrees advance on base ign timing is like pi$$ing in the ocean.

like i say, some people love the mod, some hate it. some are indifferent.
i just say blah.

[Night Rider]

Had mine on for over a year now & no probs yet. Knock on wood. ;)

[black97cam]

Nikon did this to my car the other night...I've noticed no difference.

So im just gonna take it out and plug it back into where it belongs.

[Patrick Javert]

If you wanna properly advance spark, get a HPP3. you also get a bunch more stuff than just spark advance w/ it, too.

[SunsetOrange98Camaro]

I dont know if this is the best place or not to say this but my air temp module is for sale.

Click here.

[strange_trp]

no matter how much you go in and manually change spark advance, the pcm will automatically cut it back when it detects detonation. this is a good thing, as detonation (aka preignition or spark knock) can destroy connecting rods and journal bearings. at WOT the pcm will give you as much spark advance as you need. nobody has shown on the dyno or the track that simply increasing base ignition advance results in performance gains on these engines. the days of turning the distributor to get a little more HP at the rear wheels are over. to get more power out of these engines, focus on getting more air in. the pcm will take over from there, without any special chips or programming.
a lot of guys get the power programmer and don't know exactly what they're doing and why. then they end up with their car in the shop for a week becuase they wanted what amounted to about 5hp more at the rear wheels (if that much).