Im considering putting a underdrive pulley set on my truck. It is a 2002 5.4L what i want to know is what is everyone's experience with them if you have a kit. And also are they worth the money im going to be paying for them with?

 

the more economical choice would be a programmer from a tuner that does custom tunes.....I only say this cause I'm glad I had one when I put the UD's on cause I had to bump the idle up for the alt to keep proper voltage while idling.....you could get the UD's along with an overdrive pulley for the altenator....

 

i've had them on my truck for about 3 and a half years now. The only down fall is that my power steering is a bit harder at idle while in gear. there have been only 2 mods I have done to my truck that have actually helped gas mileage. E fans and UDP's...

 

Wihtout replacing the other pulleys to compensate for the reduced diamter, you have possible issues with power steering pump efficiency (at very low speed) and charging system issues (if you get stuck in heavy traffic for extended periods)

 

I dont drive on highways very much soi dont think ill need to worry about charging issues.
Gotts2bme: how much would you say your mpgs increased when you installed them?

 

Wouldn't replacing the other pulleys to compensate for the smaller diameter of the UDP kit be pointless?

 

I never noticed any power steering issue however I had stock size oem tires....just an overdrive one for the alternator is the only one to really compensate for...

Here's one from bbk for the 8 rib belt..... http://www.americantrucks.com/bbk-un...-9703f150.html

 

What kits did yall use i swa the bbk one i just want to know what my options are

 

it all depends if you have the stock oem 8 or 6 rib serpentine belt....I got mine from troyer performace for my 06 5.4 3v which was 6 rib....www.troyerperformance.com

 

I had some on my truck and they reduced the speed of the AC compressor at idle making it a lot hotter in the summer. My truck seems to have loss some low end torque also so I took them off. If you would like then I will sell them to you. They are red from Brenspeed.