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Discussion Starter #1
Hi supra freaks, I have a question for all the gurus, I just installed apexi mechanical boost gauge, tapped it to the intake manifold. For some reason It shows the vacum?, but doesnt show the boost above 0psi, its all below 0 like -5 or so.
Could some one point me to the right direction please, I would very much appreciated it. I dont know where to start, the engine runs strong, but for some reason its not boosting.

Thanks
Carl
 

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Theres really no tricks to setting up a mechanical boost gauge. Make sure the fittings are tight, and not leaking. Did you use teflon tape on the fitting at the gauge and the fitting at the manifold? If the fittings are leaking, then it may show vacuum, and not positive pressure since all the pressure will be leaking out. Also, vacuum at idle when warm should be about 20 In/Hg.....is that what its showing?
 

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Make sure there isnt any kinks in the line going to the gauge. I have had that happen once and it wouldnt show boost.
 

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Discussion Starter #4
Well guys I am pretty sure there are no kinks, I tapped it in the back of the manifold where it goes to the T by the firewall. Just dont know why its sucking air at that T point. The gauge still in the engine compartment, I took the car for a drive but the hand on the boost gauge only goes down to the negative side below 0, instead of going up. Will post a video of it later on tonight.
Rays turbo at idle it steady between-5 or even lower in kpa readings.
Thanks
 

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Do you have a factory boost guage still? If so is it reading boost?
 

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Discussion Starter #6
The factory gauge did the same thing, no it didnt read the boost either. I thought it had issues so I replaced it with the volt meter, thats why got the mechanical gauge.
Come on guys you gotta know why I am not getting the readings.
Help helpl help please
Thanks
Carl
 

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Did the car boost fine before you put in the gauge? You could have a massive boost leak that would cause the gauge not to read boost. Another thing is possibly the wastegate actuator fell of and the wastegate is stuck open. That would also make the car not boost. But if the car still boosts fine then disregard everything i just said. Are you 100% sure that there is no kinks in the line? Im just saying this because when i redid the vac line for my boost gauge i actually had a kink in there and it would only read -10 on vac and respond real slow when i would give it gas.
 

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if your reading -5 at warm idle you have a rather large boost leak somewhere. like said there really is nothing to a mechanical boost gauge, you plug in the boost source and it works nothing more. start looking for a boost leak or several perhaps.
 

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Discussion Starter #9
Thanks for the help guys I'll be looking for that leak.
Much appreciated.
 
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