914871 Underdrive Pulleys

I installed this 3-piece pulley kit from ralco rz on my 2006 Honda Accord coupe 4-cyl K24A8 about 2 months ago. I was able to keep the original size gates belt I had on before the swap. (If it seems loose after the swap, try just getting a new gates belt in the same stock size and see if a fresh belt will fix it before trying a smaller belt.)This is indeed an underdrive pulley set however, and i noticed a dramatic increase in performance, particularly in third gear. The crank pulley is a smaller diameter than the OEM pulley. The power steering is about the same size but lighter weight. The alternator pulley is a bit larger than the OEM piece.In the instructions for the installation you will see it says that it takes about 5-7 days for the ECU to realize the smaller amount of rotating mass, however you can greatly reduce this time by performing an ECU reset on the car. (Google Honda Accord idle relearn procedure).I'll update my review if it ever causes me bearing issues on the crankshaft or whatnot. But so far I'm not worried and the pulleys all seem well balanced.

On my 2006 Acura TSX the Ralco crank pulley rubbed the timing cover for a couple seconds on the first startup after install but the pulley quickly shaved enough off the timing cover and the grinding was gone. 2,000 miles later and still running fine. I don't really feel too much of a difference but I read that was to be expected with an automatic transmission. At least it added some shine to the engine bay.*9-Feb-2016 update: Got about 5000 miles on the pulleys, no issues.