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Difference Between UDP and the FC Pulley Kit?

587 views 15 replies 9 participants last post by  speedy_zx3 
#1 ·
Is an underdrive pulley included in the Focus Central three piece pulley set or no? help please...
 
#3 ·
well in a sense they are all underdrive pullies..but yes the "crank" pulley is included in the FC kit along with a water pump pulley and an alternator pulley..its really less of a hassle and the same amount of gain to the the AFX UDP
 
#4 ·
What FocusOnMyZetec was TRYING to say...

was that the AF/X single pulley will yield almost exactly the same gains, while being MUCH easier to install.
 
#5 ·
So the AF/X UDP will put out the same gains as the 3-piece FC pulley kit? (Which includes a UDP like the AF/X) right? Or am I confused... I am looking to buy one of the two but can't understand why the AF/X single pulley would put out the same gains as the FC 3-piece kit... any help?
 
#6 ·
Originally posted by SilverFociRacer:
So the AF/X UDP will put out the same gains as the 3-piece FC pulley kit? (Which includes a UDP like the AF/X) right? Or am I confused... I am looking to buy one of the two but can't understand why the AF/X single pulley would put out the same gains as the FC 3-piece kit... any help?
<font size="2" face="Verdana, Arial">yes same gains...
 
#7 ·
Ask yourself, why does an underdrive pulley "make" horsepower in the first place.

The accessories take power to turn.

The accessories are all spun off the crank.

If you make the crank pulley smaller (crank UDP), ALL accessories spin slower, and consequently take away less power from the engine. The AFX pulley is one of the (if not the) smallest pulleys, and consequently spins the accessories the slowest.

With a 3 piece pulley set you are spinning the crank slower, and also have larger pulleys for the two accessories to spin them slower as well. But the crank pulley isn't likely as small as the AFX pulley, otherwise the accessories would spin way way too slow (and harm functionality of those accessories too severely).

Point is that its ok to gain some power by spinning your overengineered accessories slower, but there are limited gains if you still want them to work well at all at lower rpms. The only real advantage of having multi-piece pulley sets over a single crank pulley, is that you can underdrive different accessories uniquely (one more or less than the others). But since all were engineered with similar specs, it may not be worth the extra hassle.

[ 12-04-2002, 08:33 PM: Message edited by: Ducman69 ]
 
#9 ·
Easy install w/ an airgun/impact-wrench.
The AF/X will not throw you into the seat like the end of the world, but the engine will rev more freely and it'll give you as much gain as any set-up could.
Do a "Search" and you'll find install info.
It's pretty straightforward and it comes w/ directions. (Plus a little common sense for when the directions say the wrong socket-size or wrench size.
)
 
#14 ·
Basically look at it this way. Both the single pully and the 3-pully set yeild the same gain. The real question is...do you want them all to match? All the pully's to be the same color. I may or may not be correct but i thought the 3-pully system lets you keep the stock belt and the single pully makes you use a shorter belt.
 
#16 ·
you're right, sean. the 3-piece retains the stock belt while you have to get a different (shorter) belt for JUST the crank pulley.
 
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