Longggg night on the bench....had some Porsche stuff too
For reference, a straight 2.50" pipe flows 514cfm at 28" on my bench. 2017 650hp ZO6 main cat flowed 485CFM.
1. BMW M5 Main Cat flowed 524 cfm at 28". Best Main Cat Stock I've had on the Bench. Secondary Cat was 542 cfm at 28".
2. Airbox flow was tested at 10" since my car maxed out at 10" at 21.5psi of RaceChip boost at 7000rpm when I tapped the Intake with a digital manometer. Wanted to keep it real world.
3. Stock Airbox, stock filter, no charcoal filter, flowed 445cfm at 10"
4. Stock Airbox, BMC filter, flowed 492cfm at 10"
5. Open hole cut to fit the airbag inlet, flowed 511cfm at 10" which is perfection. Basically like removing the total airbox assembly and running just the pipe to the turbo.
MEGA THANKS TO MIKO....no test results without him. GREAT GUY !!!!!!!!!!!!!!!!!!!!!!!!!!!!!