I am concidering an underdrive pulley for my 4AFE toyota. I have found a decent 18% underdrive pulley. I know that I can gain a few ponies at the wheels, but I was wondering, what am I giving up? What potentially could be the downside of underdriving my other accessories...i.e. electrical/cooling inefficiencies etc?
FYI...93-95 corollas have a 3 piece crank pulley. The hub of the pulley which mounts to the crank, a rubber bushing that as far as I can tell acts as the dampener, and the grooved piece that the belts run on, which is pressed over the rubber ring and hub. After about 200k miles, the rubber shrinks a bit, and allows the outer grooved piece to slide laterally on the hub, which in turn, makes your engine a belt gobling mad man!!! Drilling 3 equally spaced holes into the pulley and inserting self tapping sheet metal screws will hold it in place, Im pretty sure this should only be used as a temporary fix though because there is nothing damping the vibrations (all this may be moot though as the inline 4 is internally balanced, and a local Toyota tech I know says the rubber ring is only there to keep the engine quiet). Anyway, this is why I want to replace the pulley in the first place, and Im not a fan of putting money into this car unless it makes the car faster.