My 07 SS SC is running at 8 psi. Is that normal?

 

its claimed to be 12 psi

but most see 10-11 psi

did you purchase your car used?
is the exhaust modified?
possibly the head is ported?

 

he's in Canadia that'll effect it

 

8 psi is really low, should be at 12psi during WOT towards end of 2nd and 3rd gear, if ur only boosting at 8psi, then possibly have some belt slipping going on in there.

 

on a stock pulley, ported head, air box mod, header and downpipe and catless I would max out at 10-11 psi. I personally have never heard of anyone only getting 8 psi.

 

I live in Canada and when my car was stock it was 11.4. 8psi seems way too low

 

bad gauge ?!

 

ringland goin out?

 

i would say ur belt is slipping, so try to tighten ur belt up and see if that helps

 

I push 13 PSI on mine.. Stock besides intake and exhaust. 8 PSI does seem very low.

 

Well, here is another issue that may be related. Once in awhile i get a rattling noise at idle, and goes away when i rev, but comes back periodically, and i heard it was the timing chain hub, or tensioner, but gm said they wont fix it until they reproduce it, and it doesnt happen all the time, so could that affect my boost limit?

 

Wow.. I'm on 14psi on GM Stage 2, all stock other than that, but still.. Either you've got a magical car, or mine is fucked up..

 

Rattling at idle that goes away when you rev is probably the coupler in the SC, though it could be the timing chain tensioner but the timing chain tensioner usually still makes noise even when you rev. That shouldn't effect boost levels though, and if you max at 8psi at 5500 RPM in third then there is definitly something going on.

 

Thanks for the info, i will get gm to investigate cause im buying the car off the lease in a few weeks, and want it to be running propper.

 

I got that too the other day.. My car has 60k on it now, and I heard it the other day and it scared the **** out of me.. It sounded like it was coming from the SC.

I was told SC coupler, as someone above said.

 

so your saing boost is based upon the country in which you live in?

 

oh absolutely. mine varies by state even. in wisconsin i run at 12 and only 10 in minnesota

 

lol...

 

Serious. On the SC you even see more boost in the winter.

Why do you think stock TC's run diff boost through out the country to get the 260 cap?

 

elevation makes it harder for sc to make boost.

 

I figured it would make it easyser...

Isnt boost the diffreance between intake manifold absolute pressure and outside statit pressure??

If you decrease the outside static pressure (as happens at higher altitudes) , then woudlnt that show a rise on the boost gauge if internal intake manifold pressure is the same?

But then you also have less air for the SC to pump,
but
less resistantc?

Would be interesting,
I figured thes things would boost great in the mountinans. Just you have sea level performance as if it was NA.

 

8 PSI is pretty low .... has it always been 8psi ? I would check and make sure the bypass valve is adjusted correctly and that it's not hanging open a little.

 

Ok, so i was on the highway going up to the lake, and decided to punch it in different gears and got some weird results! Second gear WOT i hit 8 psi. 3rd gear WOT 8psi,4th gear 6 psi, and 5th like 4 psi? WTF is happening here? Even first im pushing 6 psi? The car doesnt feel slow, but stock i was beating my buddys mustang gt(2003) and i was stock, then in fourth he started to pull away slowly. Ive in stalled since then a kn typhoon CAI, XTC dwnpipe W/hi flow cat, and a magnaflow catback. Im not tuned yet either and still have a cell thrown till i get tuned, but we ran again, and results were the same? My fastest time stock at kayuga was 14.2 . Im frustrated and the dealership is pissing me off!(*******)!!! they want 109.00 just to do a diagnosis. Im buying the car off the lease, so i want it in good running con.

As far as i know it has. I thought maybe cause it was a leased car the dealership had some governor for boost or something>LOL I have only 59000 km on the car and its a 2007, so i baby it, and do all maintenance, but have the boost problem maybe since ive owned the car. I know in the begining it was low cause it needed to be broken in, so yeah LOL?

 

Seeing as you went 14.2 I'm betting it's a bad gauge .

 

Mine too on cold/cool nights