Boost drop at 5100 rpm from 7 to 3 need help

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pauliedrft
Posts: 471
Joined: Tue Oct 07, 2008 12:06 am
Car: 91 240sx

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Im running a zenki sr20det tial wastgate 8.7psi,peak boost manifold 11x24x3 fmic , type rs bov ;what could cause it to drop down to 3 psi 5100 to redline . At 5000 it hits 6-7 psi and just falls on its face after . Waste gate reference is coming off my boost gauge off big line right under throttle body going to intake . Any help would be nice i have looked .And would a mbc help ???


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Wretched
Posts: 265
Joined: Sat Aug 22, 2009 12:51 pm
Car: 93' Hatch

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I try to run the wg reference on its own vacuum line first. Also, try tightening up the bov. I've seen a bunch of leaks come from there. And why would it not run ~9psi with that wg spring? A boost controller probably won't help in this situation, btw.

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pauliedrft
Posts: 471
Joined: Tue Oct 07, 2008 12:06 am
Car: 91 240sx

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yeah its a stupid knock off bov im going to put a block of plate on it this weekend and see if it makes a difference if that doesn't fix it im going to do another boost leak test and go from there .I also forgot to say i have a thermal intake gasket if that makes a difference .


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