what will they do for me if i bought some?

 

I hear you can teach them to retrive the morning paper and make you coffee!

They are usually lighter that stock, and underdrive certain belt driven accessories (spin them slower). The result is less power spent turning the accessories, and more power driving the vehicle forward (or backwards depending on gear). The downsides can include: the alternator not keeping up with your electrical demands and your power steering becoming harder to steer. I am not sure if the AC compressor is affected by the pulleys or not.

 

I know that they are mod number 1 on puny little Ranger engines. I've never bought one, but many people swear buy them.

 

You just opened a huge can of worms


for the money $150+...the results are insignificant. You'd be better served buying a set of e-fans and removing the mechanical fan


U/D pulleys are great with light vehicles...but these trucks are heavy pigs. You might gain 3-5 HP...might...but the weight of the truck is gonna make that gain almost unnoticeable

 

so e-fans would be better for me?

 

Isnt the other way around, since they are weigh less they will spin faster and free up some ponys. Thats the reason people get them. Same with lighter pulls on super charges allows it to spin faster.

 

When you underdrive something you are turning it slower. By contrast the overdrive in the transmission allows it to turn faster while allowing the engine to turn at a lower RPM to increase MPG.

 

Change that almost to "not at all"

Please do a search and you will see plenty of threads on this topic. UDP are 100% worthless on a 5000lb+ vehicle. 100%

It's like throwing a chair off the Titanic!
Is the ship lighter?



This doesn't even make any sense......

 

yes. your engine won't be lugging the weight of the mechanical fan around anymore


so you get 2 benefits

1. engine will rev up quicker
2. less parasitic drag from the fan operation


this will gain you HP and possible MPG's...depending on how you drive it anyways

 

as fast as it will go............
NA...i do 90% of my drive on the Interstate to and from work. around 75 to 80 MPH. 116 miles round trip everyday.

 

Speaking as someone who has just installed them recently, on my 5000 lb vehicle. You might feel like you've picked up a litle power, but it could also be that last tank of gas that you got. Whether you feel it or not, there are supposed to be gains . if you get 5 horse here and 5 horse there doesn't that still equal 10 horse, so a few insignificant ad ons might make a small ammount of difference.

 

Please see :
IF you actually gained 5hp (and that's very generous regarding UDP's), you WILL NOT NOTICE IT on a full size truck. You may dupe yourself into thinking you do (to justify their expense), but in REALITY, it's not happening.

I speak from experience, but not from installation on a 6000lb truck with 3.73 gears, rather on a 2900lb Mustang with (at the time) 4:30 gears.

If they sold them for $25, then what's $25 bux? Big deal, but not for the $100+ they sell that stuff for. WORTHLESS. Anyone who argues that they actually feel a difference after installing UDP's on their 5000-6000lb+ truck is telling me a whole lot about their "knowledge" of mechanics/racing (more like the lack there of....).

It's quite simply a matter of physics. A 3-5hp gain is a drop in the ocean when talking about a 5000-6000lb+ mass.

You would stand to gain about the same effect by simply removing your spare tire and jack......

 

What does it matter? If someone installs an underdrive pulley kit and believes they can feel a difference from it who is it hurting to let them believe that? There are other benefits to these kits, such as they look cool when you lift the hood especially when they're combined with other mods. They also allow you to use a shorter serp belt then stock which can save a few $$$ on maintenance.

If you do a series of mods that free up 3-5 HP it starts to add up. The pulley's alone you likely won't notice or an air intake alone you won't notice, just installing a set of Efans you won't notice a difference. Combine all these things together and it does start to make a noticeable difference.

 

if i bought the e-fans, do they come with everything i need to install? like the unit to tell the fans to turn on and off.

 

There are Efan kits that give you everything you need to install them. Just need to do your homework and make sure to pick a kit that fits properly and gives you everything.