Hey guys i just bought a Gm stage 3 PCM from one of the members on the forum. Im just curious if i can run Lucas 42# injectors and a 3.0" pulley with that tune. or what would be the best pulley to run. I know that the stage 3 comes with a 2.99" pulley thats why i figured i should just run a 3".

 

The answer is yes. I have 42# injectors from GM Stage 1 and my GM Stage 3 computer ran "decently" even with the stock supercharger pulley. However, it does run VERY rich and I lost about 10 to 15 hp according to my GTech Pro RR performance meter. I would recommend running the pulley designed for the stage 3 computer, but the 3" will work ok too (much better than my stock pulley did).

 

3" is what comes with the stage 3 kit (well .01" off) so your right on

 

Would i beable to drop to a 2.9" pulley like the stage 2?

 

I would imagine you should be able to

 

yes you can, if your spraying you might wanna b 3 tho.

 

Im not going to spray. Im not a big fan of nitrous cause ive seen to many things go wrong. I would really like to hear some more info about running a 2.9" pulley on a stage 3 pcm. thanks guys

 

Just order a 2.99

 

If you want to run an even smaller pulley, Trifecta can tune your S3 PCM.

 

Since when? I am very interested in this since the Stage 3 computer that they did testing on is now mine. I would like to know more.

 

Since a few months ago actually.

Simply put, the S3 calibration can now be modified just like the stock one.

Airflow, fuel, spark, everything.

This means you can upgrade to 80# injectors, harrop, etc and still utilize the HOM switch and user adjustable rev limit.

The only things that are still elusive are the nitrous mode (due to lack of test data) and the A/C.

Since the testing was done with an 06-07 cobalt version of the calibration, any others would have to be mailed in to be read. (e.g. - 04 redline, 05 cobalt/redline)

For those who don't already own GM S3, you can purchase a P12 PCM from ebay or any junkyard, and have it flashed with the S3 cal + custom tune for cheaper than you would from GM.

If you own a Trifecta EZ Flash cable, you can just flash your stock PCM back and forth instead of physically swapping it out.

 

i didnt know this..
ive had stage 3 with a 2.85 in for a while now lol
interesting..

 

This is what im looking for how did you run a 2.85" pulley with the stage 3 tune? dosent it run REALLY lean? does this mean i can run a 2.9" pulley and be safe? im trying to figure this out before i order the rest of my stuff i need for the stage kit.

 

with my 2.85, i run a full exhaust header back, i also have all the proper monitoring gauges.
dual areoforce and a wideband.
the stage 3 tune is better than the stage 1/2 tune.
more timing and not pig rich.

i dont hammer it in the winter cuz its not designed for to be ran in minus sub zero temps .
in the summer it runs excellent, and works better with stock plugs other than anything thing else.
i also spray water. i use a custom trunk mount kit plus the dual pass option b and a heat exchanger(front mount)
last summer my tank sprung a leak, so i didnt spray and i did notice the comupter pulls timing here and there in the upper rpms (anywhere between 6500-7000) but its nothing crazy.

so if you wanna get a 2.85, it works great but youll need more cooling.

 

Go with a 2.6, meth and pro tuned lol FTW

 

Im thinking im just going to go with a 3.0" pulley right now just to be safe then when i get a wideband and a aeroforce gauge i will drop to a 2.9 so i can tell im safe and not pulling timeing. This week ill be ordering a ZZPerformance modular pulley system, a stage 2 belt, lucas 42# injectors/Harness, Option B tank, and doing a custom dual pass endplate, and maybe ill try that intake manifold spacer to see how that works. Does this sound like a a good setup to run at the moment? My stage 3 pcm should be coming in the mail this week. Thanks again SlowBalt_06

 

Hey man I also have Stage 3 and that's interesting to know you are running a 2.85 pulley on it. What are your injector PW's with the 2.85 ? My PW are pretty high on the 2.99 STG 3 pulley when i shift near the rev limiter (which i have set at 7250 rpm). I guess I would be able to lower my limter to control my PW's if I were to pulley down.