You have to convert the stock diverter valves into "blow off" mode by removing the reducting pipes and placing filters on the ends (the filters aren't necessary, just a precaution. you could also buy the awe valves, which replace the stock ones and come with filters.) I did this when i had a mr. 5 style intake.
Current: 2008 e92 335i coupe. FBO+e60 mix. Now with meth.
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