I bought a USED, 07 supercharged cobalt a few months ago. Since then, i've been constantly getting up to 20 psi on my boost gauge.

I've read on here that stock psi is 12.5ish and stock hp is 205, i've raced an srt-4, 370z, mustang gt and a 240hp supercharged grand prix. i beat the grand prix, but the rest were close loses "within a car length." except for the srt4, that thang took pulled off.

my question is, is the car stock? i havent been to a dyno (cant afford it right now)

 

I would say probably not. I don't see anyway you can get 20 PSI from a stock cobalt. Unless there is a malfunction with the boost gague. You can always ask the person you bought it from I guess.

 

You should not be making 20 psi on a m62

 

SOMETIMES open exhausts can make ur boost gauge read higher. sometimes.

buuut idk if your only losing by so much with these types of cars yea ur definately not stock.

take a picture of your supercharger pulley and anything else you can under the hood.

 

the only thing to my knowledge that isnt stock is the air intake i installed last night.. other than that, i have no clue, i have some footage of me hitting 15 psi yesterday, it was hot out and would barely go past that, but when it's cooler, it hits 20 psi no problem.

and in each of those races i had two passengers.

 

Post up some pictures of the SC pulley and injectors, will give us an idea of things have been changed.

 

I'm in a supercharged base model and have beat a supercharged grand prix so it's possible that you might be stage 2?

 

 

a clogged Cat will cause 20 PSI on a m62.

 

Are there 4 bolts holding the blowers pulley on?

 

video of 15 psi yesterday

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nah

 

It looks smaller than stock but it's hard to tell from that picture. Can you get a picture of the pulley from the side?

 

exhaust brand new, had a cracked resonater and ****.

 

yea and finding a stock SC is probably hard to do too.

btw your location said "Bolingrbook" Is this supposed to be Bolingbrook, like Bolingbrook IL?

 

yeah. illinois

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how do i embed a youtube video?

 

idk i think i just post the URL and it does it for me?

Rebecca Black - Friday - Official Music Video - YouTube

yup see? now u can all enjoy rebecca

 

You got it backwards. An open exhaust system will cause boost to drop. Since there's less restriction on the hot side, the blower doesn't build as much pressure. Freeing up the intake side (pre-blower), however, will cause boost to go up. Think of it as trying to blow through a straw (a lot of restriction) then trying to blow through a piece of PVC (virtually no restriction). Pressure inside the PVC is a lot lower than inside the straw. Same principle applies here.

OP: If you're boosting to 20psi, you are either running a 2.7 or smaller ( I saw 17psi on my 2.7 before the belt blew up), or you have a massively clogged cat causing serious restriction and therefore uber boost

 

look closey to the pulley and there is probably a number on it if its dropped down which it does look smaller than stock. anyways, 20 psi is def not normal. stage 3 gets ~18

 

CarTunezSC - YouTube

 

I can't tell what im seeing in the vid lol

 

i'll hollow out the cat and see if that'll change anything.

I'll check it out.

 

Is it an aftermarket DP?

 

I see a plate where someone had a stiffy mounted on there . You really cant see the pulley size on this pic, but it looks really close to the s/c snout. if there are 4 or 5 bolts on the s/c pulley then that will explain why you are seeing alot of boost. If that is the case you might wanna clam down abit because i dont see any cooling mods for a pulley that small.

 

there are zero cooling mods from what i see too... and it's kinda freaking me out.

anyone here twincharging? i have parts from a turbo build that i wanna throw on there.

i read a sticky thread saying yall throw in extra injectors for tuning and what not.