Just recently changed out my supercharger on my 2007 cobalt ss lsj now I'm loosing all boost at 5k but the boost gauge continues to go up it falls on its face when I 5k any suggestions on what may be wrong??
I have ZZP stage 3 kit with the 2.8 pulley also have zzp header and down pipe with a DNA catback

 

My first suggestion would be checking your supercharger bypass valve actuator boost controller.

 

Do you build full boost up to 5k?

 

yes I am

 

You have any check engine lights? I would guess that since everything is normal until 5k then it suddenly drops that your ECU is pulling boost or throttle for some reason either something wrong with a sensor or it is seeing something it doesn't like.

 

Just checked my engine lights and I had a random misfire and a lean code but it has had it for almost a year

 

I would think a lean reading would be enough for the ECU to cut boost. It makes sense that it would anyway. You don't want to be boosting if your car is leaning out anyway.

 

How would I fix the lean issue???

 

to many misfires at load can cause it also

 

You have to figure out if you are getting more air than the computer is detecting, which would most likely be MAF sensor reading maybe MAP. Or alternatively if less fuel is being delivered than commanded like from low fuel pressure or clogged fuel filter.


But before we get too involved in diagnosing mechanical problems tell us about your tune. You dropped to a 2.8 pulley, did you have your tune adjusted to compensate? If you had a "bad" supercharger before you might be moving more air than you were before which can cause a lean condition if your tune wasn't adjusted.

 

I didnt do the stage kit the previous owner did so im.not sure on the tune I know its tuned to run only 93 and I'm on 60# injectors I'm going today to get my tune looked at also my whistle noise coming out of my exhaust

 

Looking at the tune is a good place to start. Hard to say what the whistling noise could be.

 

Yea it's very hard to tell it sounds like a have a turbo in my exhaust 😂