Underdrive pulleys

I hear a lot about under drive puleeys and I was wonder what is better about them?

They allow the crank to spin more freely. Less drag on the motor bassically. They dont add any hp, they just kinda free it up.

yup... not much of a noticable difference, but in the end, it all adds up.

lets put it like this, on my i4 ESCORT dynod another 5whp 8wtq in spots of the power band and 1whp and 3tq peak from just 1 pully

on a v8 im sure you will se a gain, just not sure if it would be more or less.

I put a crank underdrive pulley on my 5.0 in my truck. I could tell that the motor reved more freely and seemed to rev quicker with ease. Not really a seat of the pants difference but a good move none the less.

I believe MM&FF magazine got an 8hp increase on a fox body car by just changing to underdrive pulleys. When i did mine i could definately feel the motor rev up quicker, but there wasnt a huge sotp power increase. For the price, i'd do it again.

i just put them on my v6 today... didnt do that much...

On my 92 5.0 5spd. my mods were 12 inch K&N cone, Flowmaster muffs, then I added March race pulleys which they say are good for 15hp at the crank, and they have a street set which they say are good for 10hp at the crank. With the race set I basically had to learn how to drive the car again! I noticed a HUGE difference, that was w/the race set however. A year later I switched the race crank out for the street crank because I got tired of having to keep the engine reved up to charge the battery and keep the water pump turning fast enough to cool the engine. The race set is NOT for auto. cars. YOU WILL have cooling and charging problems. But w/ 5spd.'s (like mine) the race set isn't bad during the day (charging) but at night, with the lights on and wipers (in the rain) then you put the A/C on on top of that. Just hope and pray that you don't get caught in stop and go traffic. Anyway, like I said, I did notice a HUGE difference with the pulleys. If you have more mods or you use the street set, you may not notice that much of a difference.
MAN, I CAN WRITE SOME BOOKS HUH?

thats why you get an ODP for the alt. to keep it spinning at the right rate

the 17% ODP doesent do that much for the alternator. i didnt put mine on and it seems to be charging almost as well as it should be but ill probaly put it on next weekend

What the hell is an ODP? Old Dirty P****? Sorry...I still act like a 12 year old sometimes. But seriously what is an ODP? Thanks.

overdrive pulley

i know peple that put a 33% reduced UPD on there cars then an ODP and still power systems w/ 3, 12in subs.