Re: 178mm needswings pulley is installed. need a help
So you did install all three pulleys that came with the kit? Also did you do a throttle reset? No you shouldn't get any belt slip with the 178 and no you shouldn't have any detonation with the 178 and no tune. I ran for 6 months with a Needswings intake and ASP 178 kit and no tune, and everything was fine. Car was running very rich the whole time. Definitely will feel a huge difference when you get a tune. Just make sure to do the throttle reset and let the ECU start learning your new habits.