TVS issues
10-17-2011, 08:56 AM
#1
TVS issues
hey guys. as some of you may know i recently installed a TVS on my car with a 2.7 pulley. Car pulls really well, and isnt even dialed in all the way yet. Still around 11.2 to 11.5 afr at wot. Heres my issue. I installed a 3bar tmap sensor for the lnf in hopes of the stock boost gauge and pcm being able to see the added boost. We installed all of the correct values for the upgraded tmap and got it working nicey. Some people said that the lsj's pcm limit was 21.7lbs of boost. After dialing the car in my tuner and i noticed the pcm was seeing 22.05lbs of boost but that seemed to be the limit. Heres another weird thing under a hard 2 to 3rd gear pull, my stock boost gauge would go past 20, spike then would bounce around like it didnt know what was going on. I installed a mechanical autometer es series gauge with 30psi capabilities hoping i would be able to get an accurate reading of how much boost the car was seeing. Heres whats going on now in the logs we would see boost spike around 24ish then fall off to 22psi, and hold steady all the way to redline. Im beginning to think that somehow the bypass valve is bleeding boost back into the intake and im not seeing the full potential of this blower. What my tuner and i are considering doing next is to try the boost bypass mod while logging the car to see if we see more boost. I figured with the 2.7 on a stock unported head with the exhaust setup i have i should be around at least 24psi. Has anyone else on the TVS with smaller pullies ran into this issue? and what did you guys do to resolve it? thanks in advance
10-17-2011, 02:23 PM
#8
no leaks anywhere, i replaced all the vacuum lines when i did the swap. im also right at sea level. im going to do a log with the bypass mod, if i see more boost than 22lbs then i know its related if not then guess my exhaust flows better than i thought lol
Last edited by zrated89; 10-17-2011 at 04:31 PM.
10-18-2011, 02:10 PM
#16
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The stock boost gauge just freaks after 20 psi and drops down to 0 just get rid of it and run the mechanical one. I wouldn't say you have a boost leak but at what rpm does the boost drop at? And what pulley upgrades are you running to prevent belt slip I highly doubt that is your issue.
10-18-2011, 03:20 PM
#17
there was a rumor that people said the pcm wouldnt read past 21.7lbs, even with a 3bar upgrade but weve already prooved that inaccurate as we were seeing 22.05 on the data logs. And i have already installed a mechanical autometer 30psi gauge because the stock one was freaking out
10-18-2011, 04:53 PM
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there was a rumor that people said the pcm wouldnt read past 21.7lbs, even with a 3bar upgrade but weve already prooved that inaccurate as we were seeing 22.05 on the data logs. And i have already installed a mechanical autometer 30psi gauge because the stock one was freaking out
10-18-2011, 06:18 PM
#21
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The lnfs can use the barometric pressure sensor as a work around.. i don't think we have a usable work around for the lsj..
10-18-2011, 06:24 PM
#22
LOl i think i talked with your tuner today i am not sure though. Anyways either of these are your issue with the boost, your bypass valve is opening up, or ure boost solonoid is making it open because its bad which ive seen on quite a few cars, or belt slip... With the issue of the car not seeing anything over 2 lbs, its because the vcm scanne limits. Also we in order to tune the correct fueling at wot with the higher boost you need to use pe and get your ve table working great.. If all is good you should be where you want bro!!