For those who installed C63 mufflers ...
Are C63 stock mufflers different from SL55 stock mufflers?
From my experience, just resonator delete + SL55 mufflers created a lot of drone.
And resonator delete + Supersprint mufflers also created drone.
I really wonder C63 mufflers do not cause any drone because they have different internal structure.
We installed an x pipe
Drone all gone and gave it a nice sound
My opinion sl55 mufflers are the best because they are small so little weight and nice free flowing



