hi all,
i had my S3 on APR stage 1+ for some time.
last week i installed a new VWR intake and APR Cooler and went to do some logs.

i found everything to be perfect besides one thing.
i'm loosing boost between 3500-4500 rpm, while in the same range i get a strange drop in the MAF reading.
i'm suspecting a boost leak as my N75 are maxed out at the top but i'm not sure that's the issue.
Boost logs:

Maf logs:

N75 logs:

few more things:
1. i had this kind of a drop before the cooler and intake too.
2. i dynod the car before the intake and cooler and saw a 2-3 kgm drop at those rpms also:

well? any ideas? where should i start looking?