So I'm running Stage 2 LWG 93 with mods in my signature block and I was overboosting like crazy, like 33psi crazy. So I went to Stage 3 and it just feels heavy and sluggish. I decided to switch back to Stage 2 today and see what the AEM boost gauge said and the results have me wondering how accurate the AP really is. I wasn't logging so I don't have the graph to show you but the AP said from a 3 gear pull from 3k-6k and not foot to the floor, 29psi and 4 count knock. I watched the AEM the entire pull and it never got past 25psi. The second pull, same gear and RPM's AP 33psi and AEM made it to about 23 before quickly dropping off. I'm so confused, which is more accurate, I think AEM because it's actually connected to the boost line and AP is reading ECU. Has anyone else noticed this and what or which should I believe.

 

Which "boost" line are you using?

The AP is only displaying the factory readings. I believe its the MAP sensor on the intake manifold. That would be the most accurate place to read from (the manifold) with any boost/vac. gauge.

If you are before the throttle body, you will most definitely have some difference.... how much,??? not sure.