Sorry guys sold i hope i got everyone who pmed thanks for the interest. .
The pipe replaces the primary cats and you gain alot of power with it.
Rs7 : 10.624 131.50 with a 1.7 60ft Toyo R888
F10 M5: 11.308 131.96 with a 1.9 60ft Street Tires
E90 M3: 11.2 126.7 with a 1.8 60ft Street Tires