Quote: Originally Posted by
1NiceSRT 
I would like to see the dyno charts for a true 3" dp and then a 3" dp with a cutout closed. I don't know how much turbulence you would get. Maybe some exhaust gas would get stuck in that little section where the cutout is and the rest of it would flow over the top, the same thing that happens with truck beds (if anyone has seen mythbusters).
The thing about truck beds is the cab design. Newer trucks have a slight upsweep (not always visible) at the rear of the cab to promote that effect. An older truck (50's-60's maybe even 70's) would've shown much different results.