bro, interested in your extractor, but do I get plenty of performance ( since extractor play a great role in increasing HPs ) from the B16B extractor. It's good ( since I can still use the heatshield : stealth looks ) but if I only get 1 - 2 HPs only..dunwan lah...if confirm can get at least 5 HPs, maybe I'm game for it. anyway the 4-1 extractor push up more HPs on the higher RPM range, rite? Can you explain more ( on your experience lah )..