Geez! Had a dream last night that I bought a VTDA! Help! I'm goin nuts!
#20
I think he's referring to cleaning up the flow on the inside of the stock airbox.
if you pop it open you'll see there's quite a bit of reinforcing plastic and other rough edges. IIRC gutting an airbox means just cleaning all of that up and keeping the stock filter. A few folks here have done this but I don't know if anyone has measured gains or losses.