BigRedXlt

I was told an underdrive pulley system is a cost effective way to free up a few horses on my 97 f150. Problem is I have no idea how they work? Anyone have experience with a UDP? How easy are they to install?

I found one online for $200. Is this a decent deal? It claims to free up 8-15 h.p. is this true?

AZFX4

I've never installed 1, I might here sometime in the future.

But they do free up a good 8hp atleast and they say about .5 mpg. Not sure what motor you have but the 5.4 is hard to find UDP's for and when you do they are expensive. So $200 seems reasonable.

UDP slows everything down thus not making the engine work as hard and freeing up some HP..

Atleast that's how I understand it.

AZFX4

Here's some info from Wikipedia.

http://en.wikipedia.org/wiki/Underdrive_pulleys

Franchi

I have them and yes they do add hp, I got a return of 7 rwhp on my Stang.

But you won't really FEEL a difference in the car / truck by those alone. I don't really recommend them unless you plan on doing an all out build for max HP....

A tuner, gears, those you will feel an immediate difference in how the truck drives and exhaust makes it sound good.... :-)