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Discussion Starter #1
Okay guys its me again, I'm the guy who is hitting over 22 psi on a Cobalt SS/SC that SHOULD NOT be hitting that much boost. The only mods i had at the time were an Injen CAI and GMPP Stage 2.

Many of you advised me that it was a clogged catalytic converter or that my exhaust was too restrictive.

So i took your advice and had the GMPP catback exhaust and a magnaflow hi-flow cat installed.

But i'm still overboosting at 22psi. I have taken it to two different mechanics, one was a very good GM mechanic and the other guy was a western auto head mechanic, and both of them cannot figure it out.

The stock boost gauge has been replaced and a new boost solenoid has been installed. (under warranty), so i know its not a bad gauge/read.

The car runs fine and my gas mileage is awesome. Occasionally after running it hard the blower whine will start to surge at around 6-7K RPM. But it does not seem to be a problem and acceleration does not suffer.

Please help! I love my Cobalt and do not want to melt the blower/blow the engine.
 

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It could be the sensor on the sc that may be bad, as it is an electronic piece...
 

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I got a better idea... I have a CarChips car chip in my car and you can monitor 5 different paramaters at one time. They are about $99 and you can check manifold absolute pressure, and a bunch of other things, Id give it a try.
 

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I say dont worry about it the more boost the better. Those ecotecs are damn strong you will blow other things before the motor fails.
 

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^^^ yes true, i have heard of 400hp on stock internals, but 17-18 is all that you need. Anything over that is not going to help much. If you think about it, when you boost til 0psi, you already have doubled the atmospheric pressure than that of a naturally aspirated engine. At 14.7 psi it is tripled.
 

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^^^ yes true, i have heard of 400hp on stock internals, but 17-18 is all that you need. Anything over that is not going to help much. If you think about it, when you boost til 0psi, you already have doubled the atmospheric pressure than that of a naturally aspirated engine. At 14.7 psi it is tripled.
hey its probably a sensor reading it up about 15% but who cares i have the same set up, i hope my car runs that much boost after my installation of the stg2 on my car. I Can only imagine what it sounds like, when i put that injen intake on there the superchager whine was unbeleivable. I would like for bragging rights, you run more boost than a stock evo and your rocking a cobalts thats pretty awsome.
 

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^^^ hells yeah..
 

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Discussion Starter #8
Lol, thanks guys. You are some of the most optimistic people i have ever talked to. The people over at the other cobalt site helped alot but basically said "your gonna blow your motor, better figure it out soon".

And the blower screams so loud that when i pass people, they almost start pulling over because they think i'm an ambulance or something.

Anyway, give me some more info on that car chips thing. I was thinking about gettting the aerofroce interceptor but its like 230 bucks!!

anyway, thanks for the input and keep the suggestions coming
 

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You can get the CarChips thing at any autozone, thats the only place ive seen it at so far. Where are you from anyways? If your close to NC I can let you use it than we can upload it on my pc and see exactly whats happening. I was looking at the interceptor also, art number: fx1 at autozone and only costs $99, but I dont think it reads MAF.
 

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is it throwing any codes?
 

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Discussion Starter #11
Its throwing absolutely no codes. I live in southeast Georgia so i'm not too far away from you, but still a decent ways. Hey, sounds like a good excuse for a road trip for me!

The car did throw an Evap Emissions code once but it was just a severed wire/fuse problem and was easily fixed.
 

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i bet the sc does sound like a siren if its doing 22 lbs of boost, what size pulley you got? is it the 77.9 mm one that came in the stage 2 kit? Im getting gm stage 2 put on tomorrow. How much did they charge for install on yours?
 

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Discussion Starter #13
I actually checked today and its a 77.9mm pulley, so i can rule out the problem being a bad pulley.

Oh and stage 2 rocks dude, your going to love every second of it. I got shafted pretty bad price-wise on my kit, but this was during the "stage 2" shortage that occured at the beginning of the summer.

I paid 800 bucks for the parts and just under 300 bucks for labor. Hopefully you will get a better deal than that.
 

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I actually checked today and its a 77.9mm pulley, so i can rule out the problem being a bad pulley.

Oh and stage 2 rocks dude, your going to love every second of it. I got shafted pretty bad price-wise on my kit, but this was during the "stage 2" shortage that occured at the beginning of the summer.

I paid 800 bucks for the parts and just under 300 bucks for labor. Hopefully you will get a better deal than that.
DAMN im in for 600 for all of it. dude If it s got the stage 2 from gm and everything you have done doesnt void warranty screw it if the bastard blows up then they will just put a new motor in for you under warranty simple.
 

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Discussion Starter #15
DAMN im in for 600 for all of it. dude If it s got the stage 2 from gm and everything you have done doesnt void warranty screw it if the bastard blows up then they will just put a new motor in for you under warranty simple.
Wow, 600 bucks? I so hate you.

But yea, my dealership is real cool about mods. I told the mechanic that i was probalby gonna install a hi-flow cat to try and solve the problem and he was like "awesome, tell me how it goes". So i don't mind paying a little extra on parts.

I know i'm under warranty, but i really cherish my car and would hate to see it blow. Not to mention all of my friends with toyotas and acuras would never let me hear the end of it......
 

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Wow, 600 bucks? I so hate you.

But yea, my dealership is real cool about mods. I told the mechanic that i was probalby gonna install a hi-flow cat to try and solve the problem and he was like "awesome, tell me how it goes". So i don't mind paying a little extra on parts.

I know i'm under warranty, but i really cherish my car and would hate to see it blow. Not to mention all of my friends with toyotas and acuras would never let me hear the end of it......
tell them to line them up against you and i dont think they will give you to much shit. Unless they have major amounts of money in thier rides.
 

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Discussion Starter #17 (Edited)
tell them to line them up against you and i dont think they will give you to much shit. Unless they have major amounts of money in thier rides.
Negative! A bone stock Acura RSX type S, a Scion xB, and an 04 Mustang GT.

Nothing i shouldn't be able to handle (but wait, the xB has neons so thats like what, 50 extra hp?)

But i kind of run my mouth about how reliable and practical my car is, so i kind of have it coming if something breaks. :eek:
 

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dang, i paid $617 just for the kit, then its gonna be about 300 bucks for the install. 8 hours and counting til stage 2
 

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^^^ And also, i think the warranty on the stage 2 kit only covers the kit itself for 1 year. I dont think it covors internal engine malfunctions. <-I will have to look into that though.
 

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i know a little about the car.
first i would put a vacuum guage in line.
you may have a bad signal going to the guage.
if it is pushing too much boost, then there would probably be
a oxygen sensor code for too lean.
also did the dealer try to recalibrate the pcm
because if it was calibrated wrong it would cause the problem
make sure that the oversized tensioner was put on there
ill look on mitchell on demand tommorrow to see how the pcm controls boost or if it controlled only by mechanics
 
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