I have a 2007 Cobalt SS/SC which is fairly stock. Only performance modifications that I know of are a custom 3" exhaust with magnaflow resonator with no muffler to a magnaflow tip and a Injen cold air intake. The car holds 14psi in every gear. All the pulleys are stock and this makes no sense to me after searching all over this and other forums for information. The car is crazy quick but 14psi??? Really??

PS I run a shop and had my techs check the plugs and they are one range colder as well as the part number on the injectors (12576341) are coming up as 42lb LS3 corvette injectors.. I just purchased the car a week ago so any additional mods besides whats listed above are unknown, but the 14psi on a stock pulley is the riddle I can't solve. Any thoughts??

 

Maybe a clogged cat

 

19k miles??? Clogged cat?

 

Could be, but are you sure its the stock pulley? The stage 2 kit come with the 42lb injectors .

 

does the pully says 77.9? it could be that is just a stage 2.

 

see thats what i am thinking is you have a stage 2 setup does the pulley have bolts in it or not

 

doesn't cobalt addiction make a pully that looks stock? and some other companies as well?

and how do you know the pully is stock? for someone to have 42# injectors and colder plugs, just makes sense that the pully is not stock.

 

GM Stage 1 comes with the 42's but keeps the stock pulley. You may have GM Stage 1.

 

I'll see if I can get a part number off of it. Maybe that will help. I'll mic it too to see what size it is, but it looks like a stock stamped steel pulley.

 

yea but who gets gms1 on the ss/sc

 

i know i've only seen two people doin that setup. that makes him the second one. they just send the injectors and the code to tune it at the dealer...suposely it does 230hp, but with the pulley thats when it rates at 245hp...

 

actually, i did when i first bought my car 2 years ago. i knew i was going to go GM S3 one day, so i bought Stage 1 for the injectors and the tune. I wanted the tune so if i needed to go to the dealership i could switch out my GM S3 ECU for the production ECU with the S1/S2 tune on it. if the stock pulley is on the car, and he is running the gm 42's, I could see it being GM Stage 1. it could also have a custom tune considering he doesnt know much about what was done to the car. in all reality it's prob his cat ready to take a ****.

 

Pulley has no bolts and looks to be pressed on. Who knows??

Clogged cat even though it runs like a raped ape huh.. I suggest everyone clog there cats if it wakes these cars up that much DAMN. lol.. I'm thinking the previous owner had someone make a pulley or something. It looks bone stock and is stupid fast.

 

I'm just listing some of the possibilities.

 

i had a couple extra psi of boost outta my stock pully, but only in cold weather
but most likely clogged cat, i just had to replace mine.
i was hitting 21 psi now down to 18-19 and im not stock anymore...

 

i currently have my cat clogged and it boostes alot more than its suposed to. am pretty much stock and only have a CAI and headers. the car doesnt run so good tho.

 

when my cat clogged all i did was drill out the filter or you can take anything that fits and shov it out likr the guy said above. all you have to do is unbolt your down pipe from the headder and where it meets the exhaust pipe then its out, next you rip out the fitler (pretty much making it catless except for the hollow cat body), then just bolt it back up

 

cobalts are very underestimated cars, most people still think they're just a cavalier. I certainly wouldn't call a 42# cobalt with potentially a stock pully stupid fast though lol. Are you sure you have the stock blower and not a tvs?

 

LOL. tvs on a stock m62 pulley?unless hes not sure what pulley and supercharger he has...whats the normal pulley size on the TVS anyway?

 

i believe the TVS comes with a 3.15" pulley stock.

 

so its about the same size as the stock pulley for the m62. alright cool.

 

I just can't imagine a stock pully car with an exhaust being called fast... guess it depends what you drove before.

 

This.

 

Trust me its pretty fast. I use to have a 418ci Stroker Z06 hence my screen name. The gentleman that lives next to me just purchased a C6 Vette and we ran two races Friday evening. 30 roll to 110 Vette by a fender at most and dig to 110 Cobalt by 4+ cars.

My pulley measures roughly 3.1 inches at the ribs. How can I tell which blower is on it? I do not know much about these cars being I've owned only Vettes for go fast cars since 2003 and have only owned this car for barely a week.

EDIT: Pulley measures 3.0875 exactly using digital micrometers.

Thanks for all the input guys. Like I said I really don't know a whole lot about them and this is a learning experience for me. I have a whole new respect for these cars.

Okay I figured it out.. Just got home from the office and looked through the folder I got with the car. There is a receipt for a company called Steigemeier saying it has a "Ported & Plugged" supercharger on it. Pulley diameter is 80mm according to the paperwork with a custom dyno tune but no dyno graph Not sure what "Plugged" means but hey at least I'm not worried about it blowing up because of a stock tune on 14psi. The supercharger is very loud I've noticed but other than that everything seems good.

Thanks guys

 

Take a pic of the blower and post it. But unless the guy driving the vette sucks ass, (that's being nice) or there's some major work done that you don't know about, there's no way you should be anywhere NEAR a vette from a dig-110, especially when you're losing a roll race. With the mods you know about, you're a low 14 second car, MAYBE very high 13's if you're a great driver.