Hi guys i need help. I have a cobb apv3. During idle the boost reads negative 8 to 9psi. But when i drive at at 5000 rpm it will only go to 17psi. Im using stage 1.

Pls advise

 

sounds fine.

 

negative is the amount of vacuum...boost starts to build at 0.

 

Thanks guys

 

I thought boost peak was suppose to hit 23-24psi on stage 1. At least mine did when I had an AP.

 

That vacuum doesnt seem right at all(assuming your on stock cams). I sit at -20

 

I'm using the AP3 and I'm reading -12 and hit anywhere from 24-28 psi on the Stage 1 map. I believe I have a leak somewhere

 

[/INDENT]Probably just a units issue. My AEM boost gauge has ticks for both inches of Mercury and psi. The -8 in HG is relative to the vacuum, which when converted to the relative atmospheric pressure in psi is around -18/-19.