FS:HKS wrx/sti headder
#25
You'll notice a slightly deeper exhaust tone depending on what other exhaust parts you have IE uppipe, downpipe, CBE, but being that its an un-equal length header you will still have the rumble where as an equal length header eliminates that sound
#27
I have this header and the HKS up pipe on my car. from the inside you will lose the boxer sound. from the outside you can still hear it. there was noticable gains from 2000-4000 RPMs.