Weird Boost Pressure Reading

[nick9955]

Hi everyone, need some help with a boost gauge I hooked up to my C180 Komp sport coupe. The reading wasn't what I was expecting does anyone know what I have done wrong?

I teed into the vacuum line coming from the intake just before the check valve. I get a vacuum reading at idle but then when I floor it the pressure reads +8-10psi (which I think is a bit high) then drops slowly as the rpms increase. With the supercharger shouldnt the pressure start low and build up as rpms increase?

What could this be I'm not sure where i have gone wrong. Below is a video of what happens

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[Bellow]

I teed into the vacuum line coming from the intake just before the check valve.

Can you be more specific? Where does the other end of the pipe go, what's the check valve for, in which direction does it permit flow?

I get a vacuum reading at idle but then when I floor it the pressure reads +8-10psi (which I think is a bit high) then drops slowly as the rpms increase. With the supercharger shouldnt the pressure start low and build up as rpms increase?

Does the power feel like it is dropping off as the boost falls?
Bear in mind, boost is not air flow.

 

[nick9955]

So in yellow is where I teed in. Initially i teed after the grey check valve to the left in the picture but it was just giving me vacuum and no positive pressure. I believe this line comes from the throttle body but i have no idea where it goes to.


And no the power is the same as before i installed it. The car still pulls even when the "boost reading" is reducing

 

[Bellow]

Which side of the check valve have you teed into? Engine side - yes?