Yeah i decided to do it without draining any coolant. i think they tell you to do that because they think when you change that coolant hose some coolant will come out or something, but none did. It was a pretty easy install except those stock breather and coolant hoses were kinda a biatch to get off. As for my impressions, it sounds really really cool at WOT, and that sucking noise when you turn off the car is nice too. As for performance gains, i really don't feel anything, in fact i think i might have lost a little torque...oh well i should get that back when i put on my world sport 2 next week :thumbup: