What are your opinions on underdrive pulleys( mainly the crank )

 

I personaly dont do em. or am not a fan of them. The OE made the Crank pully a certian weight for a reason. this goes the same with a Flywheel. the pully isnt just there to run the belts. they are there to absorb the Harmonics made in the engine. When you lighten the crank pully or flywheel it is totaly harder for the harmonics to be absorbed. this caused the botom end to be under unneeded stress, causing bearings to wear faster.
One of the main things Honda and all the car companies look at when building a car is cost obvously... they try to keep things as cheep as possable, but still be quality. They couldhave had lighter pullys and flywheels if it was ok for the car... after all that would save them money while building the thousands of cars... but since they didnt do it There is a reson for the parts being constructed the way they are.

 

You arent going to see any gains with underdrive pulleys right off the bat. If you planning on doing a pretty decent na setup and plan and getting a lightened flywheel etc.. then you could get the underdrive pulleys and there would be slightly less "drag" on the engine to run the belts. Like stky said tho, the aftermarket pulleys do not have harmonic balancers on them. What would be a good choice if you were going to build up ure motor and get pulleys is to have the entire rotating assembly balanced so that you could minimize the vibrations due to the lack of having a harmonic balancer. The balancing would help alot if you plan on raising your redline also.

 

interesting point never heard that side of the story...