DeepBlack SS

I am just trying to figure out if this is normal or not. in any given gear when i put the pedal to the floor at around say 3k rpm and look at the boost gauge its reading about 5psi. I have only taken it up to redline once and am kicking my self for not looking at the gauge then. so if thats not normal, any suggestions on what it could be? I did loosen the boost bypass valve and make sure it was pushed all the way down.

I am also kind of doubting that the air filter was ever replaced in all 75000 miles the car has on it, considering the.............lack of maintenance that was evident when i bought the car. could the air filter block air flow enough to bring me down to 5 psi?

NOLAGSS

iTrader: (2)

ill bump.. and i doubt the air filter is that dirty to only give you 5psi. its pretty well closed up.. and i hit full boost when i stomp on it so no thats not normal. i wish i could provide more info but i cant. but once others see someone replied they will chime in

Jn2

iTrader: (1)

thats normal if your on the stock pulley, when i was running stock pulley i would floor it in any gear i wouldnt see 10psi until 3.5-4k rpm, but now with the 3" pulley i get 10psi @2.5k rpm

Frew

iTrader: (9)

with a three inch exhaust i see 10 psi at 3k

Zach06CobaltSC

Fail, lies...Even on a stock pulley you should see more then 5lbs of boost at 3k rpms.

I suggest that you make sure that boost bypass valve is tight and that you have no vacuum leaks. Then do general maintenance and replace everything you can afford. Fuel filter, Air filter, Plugs, Clean the MAF, Throttle Body, and anything else you can think of.

Frew - your also on a 2.8inch pulley.

Frew

iTrader: (9)

ya ya zach i just like boost braggin =-D

DeepBlack SS

The only thing that's not on it's way is the fuel filter. I did check to make sure the vacuum lines are on and as far as I can tell they are. Any perticular ones I should look at? Also wouldn't the engine run rough with a leak? It runs like butter. As for the valve I know the actuator is tight. Is there a way to actually tighten the valve?

Frew

iTrader: (9)

check the vac lines for cracks i only have 40k on my motor and two of them needed replace cause they were cracked, i think i have a leak, at idle a run between 15-18 mm hg

DeepBlack SS

Where should I be at idle

Jn2

iTrader: (1)

same here :p but ona 2.5" exhaust

-20@idle, and -22 if your driving and just dont give the car any gas and let is coast(also your a/f will be as lean as your gauge can read, mine will read 22.9a/f)

wtpcobaltss

the low boost reading could be a few things. my first guest beside a vaccum leak would be a loose or worn belt/pulley.2nd is if there is any kindof problem the pcm is reading it will reduce boost..but at 3k rpms u should see more then 5psi even on stock pulley. do u have any dtc's? if u have to dtc's...take her to the highway in mat it in second gear and look at the boost. other wise do regular maintnenece and see if that helps.

DeepBlack SS

No, no dtc's

At idle it's sitting one notch closer to 0 than 20

rukkee

iTrader: (3)

There is an adjustment on the bypass valve , if it is off a bit the bypass will remain open a hair ...bleeding boost.

Find the little allen adjustment screw. Then back it off till you can feel a noticable sticking point when opening the bypass by hand. Adjust it back in till there is no stick point....should open smooth with no hitch in it at all. Thats about the best way to do it without removing the blower.

I marked my adjusting bolt with a marker so i knew the starting position. It's not a bad idea to use it as a reference.