im in the dark here, but what are "underdrive pulleys" and what do they do?

 

https://www.ranger-forums.com/forum2...r-results.html

 

An underdrive spins the FEAD (front end accessory drive) slower. So.. your PS pump, Alt, water pump, AC compressor, and mechanical fan are all spinning slower. Up side is that your free-ing up power for the rear tires. Down side is that you run a greater risk of overheating if you sat still for long periods of time. (Which I've done with the underdrive crank pulley)

Rich

 

I wouldn't there not neer as reliable as your belt drivin fan and those fans do fail. If your like me that drive your truck daily im looking for reliable power do the headers!

 

If you do it right with quality components and not junk from autozone you'll have no problems.

 

Use OEM or high quality parts and they are MORE reliable over 150k miles.
Consider this... every new car sold in America has an e-fan.

Rich

 

Id still put headers on over an Efan. Ive had both and the headers are worth it so much more than the silly Efan.

The efan has left me on the side of the road a few times, and its a PITA off roading, always worrying about it, the mechanical fan, it spins and works, i never have heat problems with it. I go out and beat the tar out of it all day and it still works, water/mud/you name it the mechanical fan can take it.

 

Ranger? Doubt it. I also doubt the 09 F150s have efans.

 

zach, f150 and rangers are not CARS

 

again so why are we wanting to put them on TRUCKS. :)


good point though.

 

Don't the 4 cylinder Rangers come with e-fans? I'm pretty sure they do

 

if i get my ranger back, a udp is on the future mod list..worth doing the alternator pulley as well? or gains not noticeable? loss of reliability? have stock oem radio just a add on subwoofer..considering headers as well if can find decent price ...nearly $500 for v6 headers is a rip imo

 

Is there a kit to be able to underdrive the crank and overdrive the alt. or do you have to mix and match ....Thanks

 

There were some "pulley kits" but for specific engines, V8s usually, on a V6 or 4cyl the power increase is not all that much since its a small percentage of stock HP
You will often see "10 to 15HP increase", that is for a V8 only and already at 250HP to start, so maybe 5% increase
At 150HP it might be 4 to 8HP increase, not 0 so it will add HP, but...................your money