VRSF 3.5" Race Downpipe BMW 740i 640i 535i N55VRSF 3. 5'' Racing Downpipe For BMW 740i 640i 535i We are proud to introduce our VRSF race downpipe for your BMW 535i & 640i with the N55 engine. This direct bolt on high flow downpipe is THE best bang for the buck mod available. By eliminating the restrictive catalytic converter in the factory downpipe, back pressure is reduced significantly which results in faster spool, an increase in power & a more aggressive exhaust note. Our race downpipes