at 2500 about 10psi

 

what forum do find the boost mod?

 

the hiss only happens when iam driving not at idle

 

the hiss is probably from the dp... are you catless? And if you went to the 2.8 and 3" dp at the same time thats probably why you are at the same boost as before because your flowing a little better... as for it not feeling as quick... you are probably just used to it already and now you want more

 

I'm at 14-15 psi with my 2.8. It used to be at 16-17 with the stock exhaust setup. Now I'm running a bad mab header and zzp 3" dp. You being at 15 psi sounds about right with your mods.

 

Starter fluid trick

 

se i have a 3' catted zzp dp that i installed at the same time as my 2.8 and it read 18psi, and now its 15 soild, one guy said that its my zzp pcm doing it, its cutting me back to 15psi, so he said dynotune it and it will be back to 18psi

 

seriously ur not running 18psi with a 2.8 ur gauge was either off or ur cat was clogged forget about it ur right where u should be

 

I had a stage 2 for almost a year, and it was 15psi, I dropped to a 2.8, and it was at 18psi and now its 15, 18 is where it should be!

 

mines about 15-16psi on a 2.8

 

It just doesn't make sense that it was 18psi for a month then it dropped to 15 over night, like I said i was at 15 psi on a stage 2 pulley, 3.0 in, now I have a 2.8 should be at least 17 psi, does anyone know if the is a certain torque sequence for tge intake bolts? Cause it could be that I put them in out of order...

 

your boost gauge is not accurate get over it boost dont mean power so seriously get over it on a 2.8 i made 14.5 to 14.8 just get over it u ARE where you should be

 

dude i have a boost leak tester, and i used it, i HAVE 2 leaks, one is somewhere by my super, and the other sounds like it is toward the back of the motor, so get over your self, my gauge is right on, it read 17-18 for a month, the gauge is fine, that and i have no power, and runs rich as hell, cause a stock cobalt can keep up with me, like right on my bumper, it has a problem!

 

If you checked and found the two places that its leaking why are you on here asking the question? Just fix what you found is screwed up

 

i dont know for sure where it is, insofar as the one in the back i can hear a hiss but can't find it, so i was hopeful that someone would have an idea what part by the trans back by the brake/clutch res. would be leaking, that and i put all new gaskets in the intake, so i must have not installed/bolted them down right, so do they have to be torqued in a certain order, or does that intake to block have to face a certain way, because i did it to the best of my ability, and it worked for a month, so that's my problem.

 

re torque all the intake bolts to 85in lbs i think is what it is but...dude...u wont make 18 lbs of boost on a 2.8 and m62 unless ur cats clogged just sayin not trying to be a dick

 

When I installed my ZZP Long Tube Header/Catted Downpipe I went from 17 psi to 15 psi boost. Though some of that could be just because I was heat soaked, but I did expect a boost DROP and HP INcrease. Less restriction means lower boost and MORE power to the crank, because the engery isnt being used up pushing the exhaust out as much.

 

hey man i got the same thing going on with my balt.. my friend has the exact same car as mine except he has the high flow cat and the zzp true 3'' intake.. ill post more laater, at work. but i hope you figure it out. i used to boost 16 psi solid creeping up to 18 @ 7300RPM.. DID MY 3" exhaust, couple day later cant go past 15psi.. my buddies car same thing, but with larger intake and high flow cat, and he pulls away from me everytime, 16psi at the punch and it creeps to 18.. we both have 60s with 2.8" pulley. stage3 zzp kit and everything.... soooooooo idk but ill post more later.

 

Omfg!!!!!!!!!!!!

 

stock exhaust ftw

 

this thread is full of so much fail

 

 

problem is nothing u have told me i didn't already know, intake + exhaust = less boost more power because it is less restricted....duh i get that i'm telling u that with my intake and exhaust it was still at 17-18psi(at 65 degrees outside), now at any temp its 15-16psi, and a power loss, cause i have a leak or two, so i will re-due my intake cause the gasket is bad or backwards or not torqued right w/e, i heard the leak! and then i shall post pics if it get it squared away, i know for a fact my car is less powerful then it was when i installed my ****!

 

if your hearing a hiss from the back of your motor thats an exhaust leak...

 

it only happends when i boost leak test it...so the car is off.....and is not behind the block its by the trans and firewall