Originally Posted by cupcakez

Sorry to change the subject real quick but...just wanted to share what we found last night so far regarding where the boost issue is coming from:

(1) Boost Gauge shows 10.7 PSI at around 5800 RPM then the boost drops afterward (This was without any type of air filter / turbo guard on the supercharger head unit), with 3.0" SC pulley swapped out with the 3.2", and the 9PSI pulley on the serpentine side. (.74 bar = ~10.7 PSI). This was also in 3rd gear.

So we concluded that because the boost still drops and has the same pattern as before when I had the air filter on, and just a 9psi pulley swap to where the PSI dropped at around the same time (5800 - 6000 RPM) and after those RPM numbers, the boost dropped, the air filter definitely was not the issue even though it was pretty busted looking and very dirty.

We put the air filter back on for now as that's all the time that was had for until mid-november. We will do a pressure test on the car next to see if there is any leaks that maybe we missed earlier this year.

After that, if there is no signs of pressure leaks anywhere, then we will open up the blower and see if maybe there is anything wrong with the impeller. If that checks out...then I don't know.

Anyone have any other ideas where else we can diagnose this boost issue?
Thanks!