But why when I unhook that thing I still only make 11?? And is there a gm part number for that by any chance?

 

Yes that what I meant
by the bypass valve and you may also want to go back to the dealer and make sure they removed the 12 psi boost limit from the pcm when they flashed for stage 2 that could be causing your problem as well

 

The internal diaphram could have a whole or tear it causing a internal boost leak.

 

Cooper I have a 2.2 that I sc'd with a tune so its not that issue lol
Josh I understand it sounds like my bypass vavle but why when I unhook it and plu the vac line I'm still only seeing 11 psi. Aka the vavle is always shut on the sc so the bypass valve actuator isn't even being used nothing is going to itno vac lines or anything

 

Oops my bad I guess I should read up a little farther

 

its cool i just dont have a damn clue what the issue could be im startin to loose hope

 

did you check your hose that hooks up to the boost gauge and maybe your wiring? and can you give us a pic of your engine bay so we can all see it and polly find out what you have hooked up incorrectly?

 

you got it can snap a pic tomorrow when its light out can post when i get off work... unless someone can explain to me exactly how to do then i can do it while at work (if my droid allows lol) if i had a wire backwards on the throttle body vince said id be getting a check engine light. if i had one wrong on the fuel injectors the car would misfire or cel. dnt think its a wire issue. gotta be another sort of leak without a cel... or something is broke

 

You don't seem to understand what we're saying. If the valve is improperly adjusted, even if it's plugged so it always stays "shut", it will still be leaking because it's not completely shut when it should be. You have to take the SC off, loosen the bolts and adjust it so that the valve is completely shut, and then tighten the bolts.

 

i did... i thought i posted i did that when i said i replaced all the gaskets....i adjusted it so the valve is all the way shut, n then pluged it and it only made 11.

 

Then you have an issue somewhere else...is your belt slipping?

 

dont think so as everyone tells me it be a very easy sound to hear if its slipping. and i would suddenly drop boost not just never get to full boost but i dont have a clue

 

Ok back on this, I'm going to get new vac lines tonight to replace everything hard lines and all... if that doesn't fix it my buddy has another blower I can test out that I'm going to throw on there. This isn't making much sense to me

 

Ok well put the one new vac line on took the hard line off, did nothing. So to rule out the bypass valve and the blower I took a fine working blower and put it on my car. This thing had a 2.7 inch pulley on it. I thought I would for sure make proper boost with this. NOPE! It only hit 13 maybe 14 psi and that's a biggggggg maybe. I don't know what else to check. I highly doubt its my boost gauge. Yes the car felt a little quicker and more power making the few more psi but still 13 psi on a 2.7?!?!?! Only thing me and my buddy have left to guess is a heat issue. He said the blower seamed really warm for the short amount we drove. I am running only the stock h/e. And my ENGINE coolant temps heat up really quick and are at 190 driving and goes 205 to 220 when sitting at idel for little while. Anyone have any clue??? I'm gettin pretty pissed this is nuts

 

For a pulley that small you should NOT be running a stock heat exchanger. But that won't really affect boost. What intake are you running? Exhaust?

 

Hes on the money a wide open exhaust will yield less boost on supercharger I have 2.8 inch pulley that if I would have left my cat on would yielded 17.5 pounds of boost and Im maxing out at about 15-15.5 pounds.

 

I don't run a 2.7 it was just to test becuae that's what was on the spare blower. And I wasn't about to dick around with pulling hubs and ****. I run a 2.9 and I have an injen cai. The gmpp extude honed manfold, ottp high flow catted down pipe (had a stock lsj down pipe on before neither changed a thing) going into a 2.5 inch magnaflow catback. And yea I need a bigger h/e stillbut could by running just the stock one be making that many issues or heat to where I'm missing 5 plus psi???

 

on a 2.9 your missing about 2-3 psi on a 2.8 you should be pushing out 17.5 and on a 2.9 anywhere anywher from 13 to 15 but with the high flow manifold and exhaust you lose boost. Due to having less restrictions.

Thats where a custom tune comes into make up power for the lost boost.

 

So what should I be making then with my 2.9 and mods? I have a dual pass also. But like stated I'm only making 10 sometimes 11 with my 2.9. And only 13 with that 2.7. Also seeing there is only one tuning option for the 2.2 I gues its as custom as it gets right? How much hp should I be making? I think I'm going to need to nut up and thorw this thing on the dyno, idk just having someone tune my car "aka plug there lap top in and say there ya go". And talking to someone via email idk not to reassuring. :-/ that's WHEN I even get a reply or email back

 

11 is about right youll lose 2-3 pounds of boost with full open exhaust I was only pushing out 9-10 on the stock pulley after I did mine so 11 is about right.

For tuning you have 2 options someone with hptuners regardless of dyno tuners or not and Trifecta.

 

Holdddd it since when can hp tuners tune my car? Thought trifecta was my only option for the L6. And 11 seams low still I thought the other guys are makin like 15 or 16 with the same set up as me. So your trying to say me having a better flowing exhaust is hurting me?

 

Disregard yeah only the 2.0 and 2.4 for hptuners my bad man, but trifecta tunes from what I have heard are awesome.

A better flowing exhaust is not hurting you and same setup they more than likely still have the stock cat if they are hitting that high. When you relieve back pressure by adding an open exhaust you loose manifold pressure as well. So no its not hurting you you just need to get it tuned properly I had the same issue on my procharged 350z I was pushing out 9 pounds of boost then when I put the open exhaust I was pushing between 5 and 7 but after the retune I gained my ponies back. I got irritated with the procharger so I went twin turbo.

 

Well vince at trifecta swares its not the tune.... I find this hard to believe like ur saying. But at the same time when I told him I was changing from the stock lsj down pipe to a high flow cat and 3 inch dp he said that doesn't matter. So yea wtf

 

The tune is not changing your boost but did you do any data logging with vince so he could dial it in?

If you dont trust what I'm telling you put the stock cat back in it takes 30 minutes to do the swap and you'll see the boost should rise if it doesnt then you know there is an issue.

 

I was pushing about 15 psi of boost with my stock exhaust, when I swapped to the 2.5" SS/TC catback (still on stock downpipe and manifold) I dropped to 13-14.