i have the berks hfc it helped me as well.

 

I have the Invidia V3 and Berk HFC and all drone comes at interstate speeds. I really like the sound around town and have learned to accept it (drone) on the hyw. From reading, it seems to be very common with most/all aftermarket exhaust but perhaps at different speeds. You'll have to accept this risk when installing any aftermarket exhaust system.

 

Berk HFC helped my TiC dual a lot

 

Sweet

It's mainly the drone between 2 and 5k rpm that annoys me.

 

Going from TP to HFC added about 500 rpms of drone for me. With a testpipe I only had drone from 3-4k rpm with the hfc it now drones from 3000-4500 rpm

This is with a Berk 3" single exhaust that I had a shop slip-fit/weld in a Magnaflow 200 cell/inch 642-59959.