from what i have gathered so far is that the is that cranshaft pulleys are good investment but on the other hand undrive pulleys are not as hype as people claim them to be.. from researching i have pieced together that undrive pulley do free up horse power by taking a little bit from other components such as the AC, a water pump or power steering pump which is designed to operate at a given speed may not be as efficient as necessary when underdrive pulleys are installed.
So For a constant race setup or spending most of your cars time in the high RPMS it would actually prolong the life of these components ..but, for a street setup it might just od the opposite. Also after all this i think the most WHP that a person get was like +4...Now i was wondering is this information correct that i have searched for and if it is correct does the same physics apply to a FI setup...ANY information would be nice... im trying to make sure that i know just about as much info as i can -pros and cons-on all my parts before i continue my turbo setup... thx

 

anybody???

 

a lot of people have been having problems with aftermarket pulleys disintegerating (sp?) their oil pumps lately. Just do a search and you'll find out all knids of problems people have been having.