i got a standard eco in my car and my newest mod is a stock sized aluminum crank pulley from RSm racing. it only weighs 12 oz. and doesnt underdrive the engine at all. now im not sure if the crank pulleys are the same from the standard eco to the one u guys have but its worth a shot i guess. hope it helps.
As far as my experiance goes with FI and aftermarket pullys, you probably shouldnt use it. Even if it is the same size, it weighs less. The less weight wont have the momentum to turn the supercharger as fast as stock and you will loose boost.
im no expert but this is my opininon. if the boot is coming from the s/c and it turning the crank to give power to the engine, then why would the weight of the crank pulley affect boost? i know that an UNDERDRIVE pulley would result in lower boost but i dont understand how a stock size lightweight pulley would lower boost. some of the s/c 2.4l cavaliers are running with this mod and some have said that theyy actually saw more boost. these are also avalible for s/c grand am/prix (cant remember which one). can someone more knowledgable explain this to me??