I just had an SLP under drive pulley installed. I had a local shop I'm familiar with do the work. It came out pretty good. And the car moves out a bit better than before. Overall impression...I'm pretty happy with it!!
So, I've heard of this, but not sure what it does. Can you enlighten me on what it is and what it does?
It is simply a crankshaft pulley like the stock one on your engine. The difference is that this one is smaller in diameter than the stock pulley and so it spins the accessory pulleys (mainly the water pump and alternator) slower. This frees some of the hp/tq that the accessory pulleys use up. It's supposed to be approximately a 6 RWHP gain seen at all RPMs. And it causes no issues with the cooling or charging systems. It also improves gas mileage. I got it used from a member on here.
The difference in diameter is too great to retain the stock belts. SLP sells 2 new belts with the pulley and a new crank bolt. Because you can't re-use the bolt either. The guy who sold me the pulley also gave me the 2 belts for it. I had to go to a dealer to get the bolt...it was only $10.22.