I have a DEFI Boost Gauge hooked up on my car and it seems to be reading too high of a number. My accessport says my peak boost is around 18.4 pounds of boost, but my DEFI gauge has peaked at 20-21 pounds of boost. Is it normal for the gauge to be off by this much? Could the Accessport be off too? It's hard to tell which reading is more accurate since both are saying different numbers. The boost gauge is tapped in by the Bypass Valve. My car is a stage 2 sti with a protune. Thanks if you can give any sort of input.

 

Defi's are know to read anywhere from 1-3 psi off. that said almost all gauges read a bit off the exact boost so don't worry too much about it unless it spikes really high.

also, which AP to you have? my V.1 was off by 3-4 psi regularly. i don't know how accurate the V.2 are.

 

I use my laptop =)

 

I have the Version 2 so I'm not sure what kinda improvements were made lol

 

yeah...the v1 was REALLY off when it came to reading boost...
and for some reason COBB took off live boost out of the newer v2...My friends got fried, and sent it back and didn't read live boost anymore. And mine never did to start out with. So maybe they're working out kinks, but i would trust the gauge vs the ap any day.