So I am under the influence that the GM Stage1/2 PCMs are pretty much the same. Regardless of whether this is true or not, here's a question;


Any one know what exactly the PCMs for each stage kit are tuned for, besides the increased redline?

 

i'd like to add a couple specific q's:

0. Is the supercharger running at maximum boost stock? (is the boost control system bleeding off boost at full throttle?)
1. Does the stg 1 tune increase the allowable boost?
2. anyone have any dyno charts with whp, wtq, A/F ratio and boost comparing stock vs. stg 1?

 

Stage 1 computer is tuned for a higher redline and the 42# injectors.
Stage 2 computer is tuned for the higher redline, 42# injectors and smaller 3.1" pulley.
So no, the tunes aren't the same as w/ the smaller pulley on the stg 2 tune, timing gets advanced slightly.

Yes, the blower is running maximum possible boost for the 3.35 pulley that is stock, it doesn't get bled off. Did I miss anything? Lol

Oh yeah, upgrading to stage 1 is a waste of money. Hp gain is only like 10 or 15hp at most. Afr's suck cuz gm tunes run rich as hell

 

I would have to dissagree with that statement. Not to call anyone out. But I am sure that there are some people here that have installed aftermarket boost controllers and have achieved more boost. Not a whole lot more, but more.

 

I haven't ever heard of anyone getting more boost out of the stock pulley unless it was from a clogged cat lol.

 

Stage 1 & 2 Tune files are the same nothing different about them from I was told at the dealership !!!!

 

Incorrect. The GM Stage 1 & GM Stage 2 tunes are identical. This has been discussed a million times on this forum. Back in the day I had GM Stage 1. I decided I wanted a little more power so I bought the a GM Stage 2 pulley & belt. The dealership did not reflash my PCM, because the GM Stage Tune was designed for GM Stage 1 & GM Stage 2.

 

^^ This is true. If you buy the stage 1 to stage 2 you do not get another tune code.

 

yes u do get another authoriztion code if u buy the kit, you wont be using the code, i suggest if anybody does that...sell the code lol ....

 

here we go again.

 

we just keep going backwards on this site don't we ???

 

oh so this thread is like a european roundabout?

sweet! I just entered and am on my first lap. I'll just stick to the outside lane so I dont get 2nd or 3rd lap around.

From my very limited understanding of what stg 1 entails, [opinion]I think the stage 1 kit is barely useful and somewhat misleading. It sounds like the 205-230hp bump is all near max rpm, so unless ur planning on driving near the rev limit all the time ur never gonna use it.[/opinion]

unless of course it does add some timing.

 

GM Stage 1's tune ("GM Stage Tune") adds timing. The only difference between GM Stage 1 & GM Stage 2 is the pulley. Place a 77.9mm pulley on GM Stage 1, and BAM you have GM Stage 2. GM Stage 1 does increase performance. It was tested by GM to knock 0.3 of the Cobalt SS/SC's 1/4 miles times.

You are correct about one thing. GM Stage 1 only increases peak power, so when you are driving normal you wont feel it. When you open it up, you will feel the car pull slightly harder from 6,000 rpm to redline (7,000 rev limit).

To everyone in this thread that still can't grasp the fact that the GM Stage Tunes are identical for GM Stage 1 & 2 give up already. They are the same tune.

 

Thank you for answering my question. I guess the one thing I was more curious about was what exactly the "tune" included. But that pretty much sums it up.

Sorry if I started another war...

 

you're welcome

 

Ok, well anywhere spark advance is increased, torque is increased but so is propensity of knock. To counter knock you run it richer.

So is the GM stg1/stg2 map richer than stock across the cells you'd be traversing in the powerband?

 

Would like to see some charts of a Stage1 Dyno. But I have this irking feeling that no one would waste time/money on a Stage1 AND a dyno.

 

THis is true!!! I bought the Stage 1 to 2 kit because it comes with an autorization code. I don't even have Stage 1, I bought used injectors, the stage 1 to 2 kit ($350) and it came with an authorization code. Why this is, I do not know, but I'm getting it installed tomorrow. GM failed on this one.