3UZ E36 dyno- ITBs and long headers

3UZFE V8 4300cc VVTi Unopened engine with 4AGE Individual throttle bodies, custom long tube headers into a single 3 inch exhaust. No mufflers Dynoed with open trumpets and then tested the K&N filters. All research pointed to conventional "sock" style filters as a power killer. Seeing this is a drift car she really needs filters so bought Individual K&N filters to test and was pleasantly surprised at only a 7hp loss.