I've had my car for about 2 months, and I just really started trying to learn about the supercharger and the boost, etc. I read that stock boost was 12.5 psi, but my car is only boosting 10 psi to the dot. What could cause it to do that? It still is under warranty, but I don't know if the guys at my dealership would know anything about it. I brought it to them with a clogged cat and they looked at my car like it was an alien lol. Anyways- just trying to figure out what could be wrong with my car. Thanks guys!

 

could be a clogged cat..is ur car completely stock??

 

when your hitting hi boost do you feel your car trying to boost higher but somethings not letting you?

 

what kind of mileage is on the car? did you buy it used? who beat the hell out of it before you bought it?

 

im seeing more girls with them..i need one

 

normally with a clogged cat you boost more cause of back pressure

 

it might be the innercooler pump couse thats my issue with losing boost but i think thats just my issue couse of the way im tuned to draw boost be4 i blow my **** up lol

 

Thats true but anythign is possible boost gauge messing up ect.....

 

There isn't really any common failure on these cars that would cause a lowered boost level. Do you have an intake on an otherwise stock car? Sometimes that can increase boost enough to get it over 12.5psi, causing the bypass valve to open. The result is a kind of spike aroun 5500 rpms and then boost drops to around 10psi the rest of the way. I've seen that happen once, so it makes me wonder.

 

Car is completely stock with 25000 miles on it. It doesn't feel like it's trying to boost more after it hits 10 psi. No clogged cat, had that changed and it was causing high boost, not low (which I think someone already said that). Wondering if maybe it had been modded before and when they took everything off, it resulted in wierd boost issue.
Second question- I am getting ready to buy gm stage 2, since it's still under warranty I want to put GMPP on it. When they reflash it does that change the boost level? Could that maybe fix the boost problem?

 

stage 2 definitely increase your boost, if you get it and it still stayed at 10 psi then for sure something is wrong..but i doubht it would fix the problem.

and also i assume you know that a stock car generally doesn't hit 12.5 psi right away, it hits it higher up in the rpm. are you seeing 10 psi all the way to redline?

 

Yep, 10 psi all the way to redline. Never goes any higher. Hits the 10 psi line and just stops dead in its tracks.

 

maybe for some odd reason someone tuned it and turned the boost down.

 

I was kind of wondering if it had been tuned and turned down. Not that I understand why they would have turned it down to 10 psi- just curious, what would be the benefit of that?

Just a side note- My car was originally sold and driven in Mississippi. If anyone knew anyone with a 2006 yellow SS/SC in Mississippi that got rid of theirs, let me know. I would love to know a little history on this car.

 

well.. maybe its not getting enough air in.. air filter could be extremely dirty or clogged

or too much air is getting out.. do you have the stock exhaust and downpipe? if you had an aftermarket exhaust you would see less psi..

other than that someone else with more knowledge is gonna have to step in

 

some poeple here have access to GMdealerworld, see if they put any new stock parts on, or any warranty work at all... worth the shot

dd u buy if from a GM dealer?

 

No, didn't buy from a gm dealer. I know the lady in the service department at my dealership though and she said that not much warranty work was done on the car. When she pulled up the page for my car it didn't have much on it. Would that show if any kits had been installed on it or other parts if they were done at the dealership? If anyone could check it again for me I would appreciate it. If so, I'll pm you with my VIN. Thanks for all your advice so far!

 

pm me your vin, I'll pull it up in gm dealerworld

 

so what ended up happening?

 

Still haven't figured it out yet. Going to go for a ride in a minute and going to check it out again.

 

Sorry to hijack this thread but it is relevant - I am having the complete opposite problem. My boost has gone up but the car does not pull in realtion to the boost that I'm seeing. I suspect it's a clogged cat - if it is, how much damage I am causing if I keep driving this way provided I keep it under 3500 rpm?

 

Get in and get it fixed! I had my cat get clogged about a month ago and it was bad- ended up having to do fuel flush, etc. Just go ahead and get it changed now.

 

the Boost gauge in these cars isn't the most accurate in the world . As long as boost isnt being bypassed out the bypass valve i'd bet its fine . There is an adjustment to the bypass valve , turn the hex screw out till you can feel the butterfly valve ,in the bypass port ,catch just a little bit when you open it . Then give the screw about 1/4 turn ( or until it opens smooth ) and see if that makes any difference . altitude , air temp , and humidity can also effect the amount of boost you will see.


Remember boost is also a measurement of restriction , seeing lower boost can also mean that you removed a restriction . If you had a clogged cat recently , the new one could be flowing that much better than the old one, thus showing you lower boost numbers.

 

Am also boosting 10psi. only mod cai. 50000 miles on it. Can you show us some pics how to do it?

 

So does anyone know whats going on with the lower boost levels?