gm stage 2 and 3
Senior Member
Joined: 01-25-06
Posts: 4,493
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From: Maryland
Stage two consist of a 3" pulley, 42.5 injectors, smaller belt, and reflash, stage 3 is a 2.99 pulley i believe, and a whole new calibrated pcm, so to switch back to having stage two you would need you old pcm, and put the stage 2 pulley back on.
Senior Member
Joined: 06-06-06
Posts: 2,729
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From: O Fallon, MO
Yes you can switch back and forth. You can swap the stage 3 and stage 2 PCMs in and out. Stage 3 comes with a new PCM that you can put ina nd out whenever you want. The stage 3 runs just fine on the stage 2 PCM, there isn't that much difference between the pulley sizes. The biggest difference between the stage 2 and stage 3 PCM is that the stage 3 has the ability to change to 100 octane maps, it requires 93 octane and is tuned for use with a 50 shot of N2O. The reason that stage 3 disables A/C is that it is not tested to be 50 state legal so they disable the A/C to help prevent you from using it on the street.
Yes you can switch back and forth. You can swap the stage 3 and stage 2 PCMs in and out. Stage 3 comes with a new PCM that you can put ina nd out whenever you want. The stage 3 runs just fine on the stage 2 PCM, there isn't that much difference between the pulley sizes. The biggest difference between the stage 2 and stage 3 PCM is that the stage 3 has the ability to change to 100 octane maps, it requires 93 octane and is tuned for use with a 50 shot of N2O. The reason that stage 3 disables A/C is that it is not tested to be 50 state legal so they disable the A/C to help prevent you from using it on the street.
Best of all, I don't have a cat and yet no CEL has come on
Im pretty sure the reason why the A/C gets dissabled is to protect your engine. GM doesn't want you running your A/C while spraying your engine at WOT. That is just wayyyy too much heat!
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Joined: 07-28-06
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From: Michigan
Senior Member
Joined: 07-06-06
Posts: 1,589
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From: Indiana
Yes you can switch back and forth. You can swap the stage 3 and stage 2 PCMs in and out. Stage 3 comes with a new PCM that you can put ina nd out whenever you want. The stage 3 runs just fine on the stage 2 PCM, there isn't that much difference between the pulley sizes. The biggest difference between the stage 2 and stage 3 PCM is that the stage 3 has the ability to change to 100 octane maps, it requires 93 octane and is tuned for use with a 50 shot of N2O. The reason that stage 3 disables A/C is that it is not tested to be 50 state legal so they disable the A/C to help prevent you from using it on the street.
not quite
Last edited by cobi; Jul 30, 2007 at 11:19 AM. Reason: Automerged Doublepost
The AC doesnt work period. Trust me I have it, It doesn't work. The reason it's disabled is because of the following reasons:
1. It's GM's way of, "Curbing" you not to use an off-road product on the streets. If its
winter time it doesn't matter because the heater still works. If you live where temps
reach triple digits you definetly need AC for comfort.
2. Since Stage 3 is not certified to be emmisions legal & it has not been tested for
long term reliablity. This is according to the frequently asked questions on Stage 3
pamphlet.
3. Nitrous is not street legal. The only way to properly activate the nitrous, is by
using the Stage 3 PCM +12vdc input and -12vdc output. The stage 2 PCM does not
have this feature so nitrous won't work. The -12vdc goes from the PCM to the nitrous
relay coil. You arm the system by feeding +12vdc to the PCM with a switch but
interrupted by a momentary 'fire' button for you to control the spray while active.
This enables the PCM to add more fuel and adjust timimg from 3500 to about 6500k
while holding the 'fire' button. If the PCM detects any knock or malfunction in the
system while spraying, it will automatically disable the nitrous.
Read here for more info.................
http://www.crateenginedepot.com/stor...s-W57C196.aspx
1. It's GM's way of, "Curbing" you not to use an off-road product on the streets. If its
winter time it doesn't matter because the heater still works. If you live where temps
reach triple digits you definetly need AC for comfort.
2. Since Stage 3 is not certified to be emmisions legal & it has not been tested for
long term reliablity. This is according to the frequently asked questions on Stage 3
pamphlet.
3. Nitrous is not street legal. The only way to properly activate the nitrous, is by
using the Stage 3 PCM +12vdc input and -12vdc output. The stage 2 PCM does not
have this feature so nitrous won't work. The -12vdc goes from the PCM to the nitrous
relay coil. You arm the system by feeding +12vdc to the PCM with a switch but
interrupted by a momentary 'fire' button for you to control the spray while active.
This enables the PCM to add more fuel and adjust timimg from 3500 to about 6500k
while holding the 'fire' button. If the PCM detects any knock or malfunction in the
system while spraying, it will automatically disable the nitrous.
Read here for more info.................
http://www.crateenginedepot.com/stor...s-W57C196.aspx
Thread Starter
Junior Member
Joined: 06-14-07
Posts: 413
Likes: 0
From: Groveport Ohio
This is all great info
stage 2 and 3 will be here this week
got honed manifold, touring cat back, 2 pass endplate, and exedy hypersingle today
how do you engage nitro mode in the stage 3????
stage 2 and 3 will be here this week
got honed manifold, touring cat back, 2 pass endplate, and exedy hypersingle today
how do you engage nitro mode in the stage 3????
Make sure to upgrade your dp. Your manifold and cat back will thank you!
https://www.cobaltss.net/forums/show...56#post1275756
I like my pacesetter, it has longer tubes and fitment was perfect. My 2.5" downpipe bolted on nicely to the header. The only thing annoying me is the whistling/chirping sound under load. It sounds like I have a farm of crickets under there......... But other than that, It let's the car breathe better.
I like my pacesetter, it has longer tubes and fitment was perfect. My 2.5" downpipe bolted on nicely to the header. The only thing annoying me is the whistling/chirping sound under load. It sounds like I have a farm of crickets under there......... But other than that, It let's the car breathe better.
Actually you wouldn't need a dp if you get the GMPP Cat-back. The GM 2.25 exhaust will probably only flow 325-350 CFM. Your dp flows around 370 CFM. So your cat-back will be the most restrictive part of your exhaust sytem.
You dont need the GMPP Manifold either. The stock manifold flows 425 CFM. The GM Extruded Honed manifold flow 455 CFM.
You dont need the GMPP Manifold either. The stock manifold flows 425 CFM. The GM Extruded Honed manifold flow 455 CFM.
Here is the info I'm referencing
The GMPP cat-back will give you a performance increase over stock. Here is the important stuff you need to know.
Below is the Flow Rates of the stock LSJ setup:
Stock manifold - 425 CFM
Stock DP - 370 CFM
Stock cat-back - 300 CFM
The GMPP Sport Cat-back will probably flow between 325-350 CFM. I dont know the exact number but if someone does please let me know. That is a 25-50 CFM increase over stock. Now I have no idea how that will translate to hp but you will see increases there.
You will not see an increase in performance by adding a GMPP Manifold. There are bottle necks after your manifold. The first being the stock dp and the next being The GMPP cat-back system.
Think of it this way. The entire exhaust system can only flow as fast as it slowest component. The 3 components are Manifold/Header, DP and cat-back system. It can get more complicated then that when building a custom exhaust but that is another thread.
Its actually really simple but when most people think of performance exhaust systems they think of size. But when you are talking about size you are actually talking about air flow.
When building an exhaust I recommend estabishing a "Flow or CFM" goal. Then replacing components untill you get there.
Hi ! Here are my flow calculation for some LSJ engine parts :
Stock Throttle Body (67 mm) : 625 CFM.
Stock Head : 600 CFM.
Stock Exhaust manifold ("Header") : 425 CFM.
Stock Downipe (DP) with cat : Plus or minus 370 CFM or less.
Stock Cat-back Exhaust (2,5" inlet to 2,25" outlet with stock muffler) : 300 CFM.
Now here are some replacement parts :
GMPP Exhaust manifold ("Header") : (30 more CFM than stock) : 455 CFM.
Shorty or long tube Header with 1,75" primaries and 2,5" outlet : at least 500 CFM.
Shorty or long tube Header with 1,75" primaries and 3" outlet : at least 725 CFM.
Shorty header with 1,5" primaries and 2" outlet : Waay not enough, who cares LOL.
Stock DP w/o cat : 425 CFM.
2,5" DP with VERY HIGH FLOW cat : plus or minus 450 CFM.
2,5" DP w/o cat : 500 CFM.
2,75" DP with VERY HIGH FLOW cat : plus or minus 475 CFM.
2,75" DP w/o cat : 600 CFM.
3" DP with VERY HIGH FLOW cat : plus or minus 500 CFM.
3" DP w/o cat : 725 CFM.
Stock catback with only the rear muffler replaced (the last portion is still in 2,25" tubing) : 350 CFM.
Stock catback with last portion replaced for 2,5" tubing and straight through muffler : 450 CFM.
2,5" catback : From 450 to 500 CFM (must be a straight through muffler).
2,75" catback : From 550 to 600 CFM (must be a straight through muffler).
3" catback : From 650 to 725 CFM (must be a straight through muffler).
Hope this can help ...
Regards
)
Stock Throttle Body (67 mm) : 625 CFM.
Stock Head : 600 CFM.
Stock Exhaust manifold ("Header") : 425 CFM.
Stock Downipe (DP) with cat : Plus or minus 370 CFM or less.
Stock Cat-back Exhaust (2,5" inlet to 2,25" outlet with stock muffler) : 300 CFM.
Now here are some replacement parts :
GMPP Exhaust manifold ("Header") : (30 more CFM than stock) : 455 CFM.
Shorty or long tube Header with 1,75" primaries and 2,5" outlet : at least 500 CFM.
Shorty or long tube Header with 1,75" primaries and 3" outlet : at least 725 CFM.
Shorty header with 1,5" primaries and 2" outlet : Waay not enough, who cares LOL.
Stock DP w/o cat : 425 CFM.
2,5" DP with VERY HIGH FLOW cat : plus or minus 450 CFM.
2,5" DP w/o cat : 500 CFM.
2,75" DP with VERY HIGH FLOW cat : plus or minus 475 CFM.
2,75" DP w/o cat : 600 CFM.
3" DP with VERY HIGH FLOW cat : plus or minus 500 CFM.
3" DP w/o cat : 725 CFM.
Stock catback with only the rear muffler replaced (the last portion is still in 2,25" tubing) : 350 CFM.
Stock catback with last portion replaced for 2,5" tubing and straight through muffler : 450 CFM.
2,5" catback : From 450 to 500 CFM (must be a straight through muffler).
2,75" catback : From 550 to 600 CFM (must be a straight through muffler).
3" catback : From 650 to 725 CFM (must be a straight through muffler).
Hope this can help ...
Regards
)Below is the Flow Rates of the stock LSJ setup:
Stock manifold - 425 CFM
Stock DP - 370 CFM
Stock cat-back - 300 CFM
The GMPP Sport Cat-back will probably flow between 325-350 CFM. I dont know the exact number but if someone does please let me know. That is a 25-50 CFM increase over stock. Now I have no idea how that will translate to hp but you will see increases there.
You will not see an increase in performance by adding a GMPP Manifold. There are bottle necks after your manifold. The first being the stock dp and the next being The GMPP cat-back system.
Think of it this way. The entire exhaust system can only flow as fast as it slowest component. The 3 components are Manifold/Header, DP and cat-back system. It can get more complicated then that when building a custom exhaust but that is another thread.
Its actually really simple but when most people think of performance exhaust systems they think of size. But when you are talking about size you are actually talking about air flow.
When building an exhaust I recommend estabishing a "Flow or CFM" goal. Then replacing components untill you get there.
Thread Starter
Junior Member
Joined: 06-14-07
Posts: 413
Likes: 0
From: Groveport Ohio
cobalt
this all makes sense and is good to know info thank am know reconsidering everything
what is the cfm of gmpp exhaust touring????????/
what is the cfm of gmpp exhaust touring????????/
Last edited by cobalt5SS; Aug 2, 2007 at 04:36 PM. Reason: Automerged Doublepost
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