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Discussion Starter #1
Last few pulls my car made zero boost. I can hear the turbo spool up, but as rpm goes up it sounds like the wastegate is popping open. I simply have my boost reference line going from the turbo compressor housing to the bottom wastegate port, top port is open. 3" downpipe, 2.5" Jones max flow mufflers and tailpipes. 8#wg spring.
 

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Since the boost line is on the bottom of the WG port the boost and the pressure built up in the exhaust pipe is pushing the valve open.

ks
 

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Since the boost line is on the bottom of the WG port the boost and the pressure built up in the exhaust pipe is pushing the valve open.

ks
That would essentially open the gate at the rated spring pressure (8psi) but he is seeing 0 psi.

Zero boost conditions are typically due to a stuck open wastegate, a stuck open blow off valve (should be closed under boost or it'll bleed all the pressure off), or a loose/open cold side coupler/pipe.
 

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That would essentially open the gate at the rated spring pressure (8psi) but he is seeing 0 psi.

Zero boost conditions are typically due to a stuck open wastegate, a stuck open blow off valve (should be closed under boost or it'll bleed all the pressure off), or a loose/open cold side coupler/pipe.
I agree 100% but I assumed he's already looked at the obvious so I tossed out another idea to help trouble shoot the issue.

ks
 

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Discussion Starter #5
I'm definitely looking into the wastegate, I bench tested it using a bicycle pump, It opened and shut freely.
 

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Discussion Starter #6
This may be off topic but may illustrate the importance of where people get their wastegate boost reference from. If a cold side coupler came loose and your reference point is in the manifold (after the loose coupler) your wastegate will not see any boost pressure, eventually causing your turbo to over spool. Correct me if I'm wrong here.
 

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This may be off topic but may illustrate the importance of where people get their wastegate boost reference from. If a cold side coupler came loose and your reference point is in the manifold (after the loose coupler) your wastegate will not see any boost pressure, eventually causing your turbo to over spool. Correct me if I'm wrong here.
This is true but irrelevant to the manifold. if it was at the compressor housing and a coupler came loose near the manifold, it's still bleeding all that boost pressure off so it has the same effect. the only difference is the manifold will still see vacuum when the compressor (and any piping before the manifold) will not.
 
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