Nevertheless, the largest restrictive bottleneck for efficiency and sound is your turbocharged vehicle’s downpipes, particularly if they have OEM catalytic converters. So as to get your turbocharged S58 powered G80 M3 or G82/eighty three M4 to sound its most effective, you have to replace your OEM downpipes with aftermarket ones. https://bmw-m4-g82-downpipe10875.wiki-jp.com/662344/the_smart_trick_of_bmw_m3_g80_downpipes_that_nobody_is_discussing