TVS: boost wont go over 15psi???!?!??!? help
06-07-2009, 12:46 PM
#29
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I'm voting boost leak. Possibly from one of your injector buckets. Also, did you replace the supercharger gasket?
Dang, I'm at like 18pounds with a 2.5 mangnaflow and 3" catless downpipe.
Dang, I'm at like 18pounds with a 2.5 mangnaflow and 3" catless downpipe.
Last edited by G85 SS; 06-07-2009 at 12:46 PM. Reason: Automerged Doublepost
06-07-2009, 01:17 PM
#31
All the electronics are still the OEM stuff though, no computers swapped or anything like that. Just the hard parts were changed.
I'm wondering, as mentioned above, if the SC base gasket wasn't sealing right. I used the one that came with the new motor but I pulled the blower to swap pulleys then put it back on. Possibility of a leak there, I doubt it but it's always possible.
I'm wondering, as mentioned above, if the SC base gasket wasn't sealing right. I used the one that came with the new motor but I pulled the blower to swap pulleys then put it back on. Possibility of a leak there, I doubt it but it's always possible.
06-07-2009, 01:23 PM
#32
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I did a different bypass today and it feels a bit better joe, but I can't tell without that damn gauge. definetely nowhere near 260whp or even close
06-07-2009, 01:36 PM
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this sounds ugly 
good luck figuring this out!
buuuuuuuuut. from what limited knowledge i know about f/i i would also vote for s/c manifold gasket. thats really one of the only sure fire things that could have gone wrong doing what you did.
BUT you said you were only boosting 15 on m62? was that before or after your cobra h/e? is it possible something got messed up? maybe something is not where its supposed to be or not attached at all?
good luck figuring this out!
buuuuuuuuut. from what limited knowledge i know about f/i i would also vote for s/c manifold gasket. thats really one of the only sure fire things that could have gone wrong doing what you did.
BUT you said you were only boosting 15 on m62? was that before or after your cobra h/e? is it possible something got messed up? maybe something is not where its supposed to be or not attached at all?
06-07-2009, 01:41 PM
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15 on M62 with GM Stage 2 is perfectly normal. Boost will also decrease if you run a bigger exhaust. I went from the stock downpipe and boosting ~17 on the M62 down to ~15 psi when I installed the 3" CTI catless downpipe....
His problem definitely sounds like a boost leak, but from where would be the question. Uhmm, maybe your supercharger gasket is on upside down. That might also cause a boost leak.
His problem definitely sounds like a boost leak, but from where would be the question. Uhmm, maybe your supercharger gasket is on upside down. That might also cause a boost leak.
06-07-2009, 01:58 PM
#37
No, even on the dyno yesterday with no fan on the front of the car, temp would max out at under 150 and drop right back to 120ish range before the next pull. Cooling system is working great.
No, the gasket isn't on upside down, it won't fit over the dowel pins and still line up with the opening...
He was only seeing 15psi on the 2.9" pulley M62, on a factory stage 2 tune and stuff. I believe all of that was installed originally by the dealership, right Josh?
His exhaust is a JBP header, 2.5" catless and straight through from there back.
15 on M62 with GM Stage 2 is perfectly normal. Boost will also decrease if you run a bigger exhaust. I went from the stock downpipe and boosting ~17 on the M62 down to ~15 psi when I installed the 3" CTI catless downpipe....
His problem definitely sounds like a boost leak, but from where would be the question. Uhmm, maybe your supercharger gasket is on upside down. That might also cause a boost leak.
His problem definitely sounds like a boost leak, but from where would be the question. Uhmm, maybe your supercharger gasket is on upside down. That might also cause a boost leak.
He was only seeing 15psi on the 2.9" pulley M62, on a factory stage 2 tune and stuff. I believe all of that was installed originally by the dealership, right Josh?
His exhaust is a JBP header, 2.5" catless and straight through from there back.
Last edited by ItalianJoe1; 06-07-2009 at 01:58 PM. Reason: Automerged Doublepost
06-07-2009, 02:03 PM
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I hope that the header isn't causing an issue with flow. I don't know of anyone that took the time to dyno one of those. Is there at least a video of the sound of it? I think that would be interesting to hear.
06-07-2009, 02:41 PM
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In a few weeks, I'll be able to find out for sure. I have something in mind I'll be doing at the end of the month that's just about guaranteed to make a lot of people mad.
06-07-2009, 02:44 PM
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Yeah the header Is garbage, but the gains were felt once I had it on. lol. never again right Joe. Anyways I just re-seated the injectors and remember when we were installing the TVS that there was a slight problem with the upper right bolt. I just tightened it down, but noticed that it seemed a tad stripped before I tightened it. Oh and I can see the gasket on the upper right, but cannot see it on the upper left. Maybe it is offset, im not sure. My car seems jacked when I just took it for a quick run electrical wise. My AC (after the and before the run) keeps going in and out. Not completely off, but doesnt blow as hard for maybe 20 seconds, then blows normal. I know they arent related its just another Prob. Im gonna change out batteries tommorow when I have the stock one fully charged.
06-07-2009, 02:45 PM
#44
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My car as well as TommySS/SC's car would hold 14-15-16lbs of boost and his would actually lose boost slightly higher in the RPM's. I had a 11.7A/F across the Powerband..
My problem was the tune. One of the tables had something messed up in it..
Just my .02
My problem was the tune. One of the tables had something messed up in it..
Just my .02
06-07-2009, 02:45 PM
#45
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Why would we be mad? It's not so much competition with me man, its getting an 300whp DD, nothing more
06-07-2009, 02:48 PM
#46
Yeah the header Is garbage, but the gains were felt once I had it on. lol. never again right Joe. Anyways I just re-seated the injectors and remember when we were installing the TVS that there was a slight problem with the upper right bolt. I just tightened it down, but noticed that it seemed a tad stripped before I tightened it. Oh and I can see the gasket on the upper right, but cannot see it on the upper left. Maybe it is offset, im not sure. My car seems jacked when I just took it for a quick run electrical wise. My AC (after the and before the run) keeps going in and out. Not completely off, but doesnt blow as hard for maybe 20 seconds, then blows normal. I know they arent related its just another Prob. Im gonna change out batteries tommorow when I have the stock one fully charged.
What do you mean by it felt stripped?
I know I had them all tight, they were just a pain as I didn't have a very good allen bit for the upper ones. Gotta get myself some ball-nose allen bits soon.
Last edited by ItalianJoe1; 06-07-2009 at 02:48 PM. Reason: Automerged Doublepost
06-07-2009, 02:50 PM
#47
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No, even on the dyno yesterday with no fan on the front of the car, temp would max out at under 150 and drop right back to 120ish range before the next pull. Cooling system is working great.
No, the gasket isn't on upside down, it won't fit over the dowel pins and still line up with the opening...
He was only seeing 15psi on the 2.9" pulley M62, on a factory stage 2 tune and stuff. I believe all of that was installed originally by the dealership, right Josh?
His exhaust is a JBP header, 2.5" catless and straight through from there back.
No, the gasket isn't on upside down, it won't fit over the dowel pins and still line up with the opening...
He was only seeing 15psi on the 2.9" pulley M62, on a factory stage 2 tune and stuff. I believe all of that was installed originally by the dealership, right Josh?
His exhaust is a JBP header, 2.5" catless and straight through from there back.
I didnt mean felt stripped, I just looked it compared to the others and it wasnt rounded or anything, just not 100%
Last edited by xpanterax; 06-07-2009 at 02:50 PM. Reason: Automerged Doublepost
06-07-2009, 02:56 PM
#48
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You're thinking I'm talking about the tvs since I have one, but that's not what I'm talking about. I'm not into proving who's the strongest, we're a community that should be sharing ideas and helping each other. It's more of a reality vs. feeling type thing.
06-07-2009, 03:00 PM
#49
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What table was messed up???
Last edited by xpanterax; 06-07-2009 at 03:00 PM. Reason: Automerged Doublepost
06-07-2009, 03:05 PM
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The car feels great, but I've run into problems left and right, since things weren't done correctly while I was gone. I've learned more than you can imagine, and I want to help where I can. It's a big comparison concerning a lot of well known companies.