Tried searching this but didn't turn up with much...

Does anyone have input on a stock diamter lightened pulley vs. an UD pulley? I'm looking at the stock diamter Unorthodox offers and have a guy that I can get it through for pretty cheap. More importantly, however, I am leaning towards staying stock diamter mainly because I plan force induction down the road. I know the differences might even be negligible, but are there any between the Ultra S and Sc? If not, I think I'll stick w/ stock diamter (save a few bucks on not having to buy new belts either).

 

I have it on my 02 and I noticed a slight power gain and the engine seems to rev up much faster than with the stock pulley.

 

If you read through the tech bits at the Unorthodox sites, you'll discover that only ~15% of the power gain is from underdriving the accessories.

The majority is from the loss of rotational mass.
Had a UR stock diameter on my past Honda, the difference was quite startling.

 

Like Steve said, the main advantage is the reduction in rotational mass. When the crank pulley came apart on my 626 POS edition (the outer ring seperated from the crank pulley), there was definitely a noticably improvement in how quickly the engine would rev and it pulled harder at higher rpms.

 

Ditto that.

I installed the stock diameter UR Crank Pulley last month, and am very content with the mod. I didn't want to compromise accessories in my daily driver by under-driving. And I didn't want to have to remember what belts would match the under-drive specs. It just wasn't worth the extra 1-2 hp.

When you put your stock crank pulley in one hand, and the UR pulley in the other, you'll have one of those "Wow!" moments.

 

Very informative stuff. Thank you guys, I now know what to purchase