Which is more accurate?

[YlwMSP]

I have a digital prosport boost gauge which reads 10 psi when I'm in full boost. Then when I have my laptop hooked up to my SSAFC, it only reads 7psi. They are both tapped into the same vacuum source, and I have no codes for vacuum leaks or anything. My boost gauge prior to installing my boost controller pegged out at 6 psi, so I would imagine that it's not faulty. Any thoughts? I plan on getting a vacuum block in the near future, so that I can just plug all my stuff into that.

 

[jeffmsp]

well the easiest test would be to try running the afc alone and see if it still reads 7psi. Running two devices off the same vac line can sometimes cause issues depending on the source, the hose used, the devices used etc..

If nothing changes try another boost gauge from a friends car and see if anything changes.

 

[Bonks]

I had the same issue, log shows 3 or so psi lower than boost gauge

 

[YlwMSP]

I had my brother hold my laptop and check what the log was reading as I drove and watched the boost gauge. The gauge would hit 10 psi and the log would say like 7 or 8, but then if I held it, they would both read like 7 psi. Maybe one is just faster than the other in terms of response.