This question has probably been asked a thousand times, but I will ask it anyways. What reduction pulley for the SC makes the most overall power? Not talking % but manufacturer wise?

 

they are all the same size across all manufactures. 17% is going to be a 17% i mean i measured my pulley that i got from WMW which is a 17% and it was pretty close to being 17% reduction in size from the stock pulley.

 

Peak performance numbers from different size pulleys are all pretty close. The difference comes in the low end numbers as the smaller pulleys will have more low end torque, but because they spin the blower faster will produce more heat causing them to be less efficient at higher RPM. This is where other mods play in. Like intercoolers, injectors, headers, and big valve heads as these will also effect boost and tuning. As you will find most people with street cars have a 15% pulley, 2nd most popular is the 17%.

 

That sums it all up pretty well.

Taking Way's information into consideration, if all you're looking to do is a pulley, also consider the above benefits in relation to the year of your car, facelift ('05+) cars are geared a little lower so may benefit more from the 15%, where the higher geared pre-facelift car may be better suited for the 17%.