I got the 3 piece BBK Underdrive pulleys, do they make a big difference? got a 5.4 with a chip and exhaust

also about how long does it take to install them?

 

I wouldn't put them on it. It'll probably make your headlights dim when you idle. Mine does it sometimes anyway when it decides to idle a little slower than usual... Just something to think about....

 

HI!... Been running as p under driven pulleys on my F-150 for 8 years and my 07 Ranger for 2 years. No problems. Luv them. This is also a good time to install electric fans if you have not already.

 

Under drive pulleys slow the alternator and thus reduce idle amps. It also slows the water pump. Neither is worth the slight gain in power for a truck that is used as a truck.

 

Kinda agree. If this is your only mod, it was probably wasted money and you'll never feel the difference at all. Even with your chip and exhaust, you wont notice a thing. However, it is my small, humble opinion that benefits are cumulative. In other words, if you're doing other stuff to try and improve mileage and/or performance, they do add some to the total package.

Couldn't agree with Neal more! Probably the best excuse for UDPs is in combination with electric fans...and a great time to install both.

Since you did get the three piece set, disregard statements about slowing the water pump down. One of the pulleys in your kit is for the water pump, and it is sized to restore normal water pump rotation caused by the loss normally induced from the crank pulley. Your water pump/cooling will be just fine.

Also, even though the alternator is slowed down and you can/may see the lights dim at idle and other funny stuff, it will cause no harm. I don't even find it annoying at all. That may only be a factor if you were running a huge stereo or other device which draws a lot of power at idle. Any throttle setting above idle will be unaffected and completely normal.

Should be a pretty easy Sunday afternoon job...couple hours.

 

on my green truck I ran MAC's for a while, I only took 'em off to install the supercharger, e-fans and ud pulleys made for great throttle response

 

I installed mine when I added e-fans and the pulleys were pretty easy to do.

 

i use my van everday as a truck,literally beat the living hell out of it- full throttle runs through the gears, tow ~5500 lbs every weekend from march till nov-187k miles- pullies have been on since new, ZERO ISSUES WITH COOLING OR TURNING OR LIGHTS DIMMING , i speak FROM EXPERIENCE of running them for 6 yrs

 

I'm running tarajerames pullies after he installed his super charger and the only time I have ever noticed a difference is that the power steering is tougher at idle when the truck is in reverse or drive. In park or neutral it is fine. I run a decent sized stereo in the truck in the dead of winter up here in Canada and it has NEVER not started for me, even in -40 degree weather it will crank up.

There are better bangs for the buck but if you are looking to squeeze out every little bit its got then they are well worth it.

 

So, if you install pulley set with a correctly sized water pump pulley to keep the same pulley ratio, you haven't gained anything on the power front, but you 'll have adequate cooling at least. That leaves the only gain as the alternator and power steering. Steering... well I doubt you'd gain much above 1000 rpm or so and going straight. There's very little load on the pump. Do you really gain anything at that point by turning the pump more slowly? Alternator? I guess that would depend on the load on the electrical system at the moment.

The bottom line for me, as a four wheeler with a 10K pound winch, I wouldn't want to sacrifice any idle amps, nor power steering at low speeds. If I was a hot rodder, maybe. Can anyone to refer me to independent tests (not mfrs tests, which are often "best case" or "optimized") that show how much power is gained on a 5.4L. The $/performance ratio is what I would be interested in, I guess.

To each his own, but not for me.

 

HI!... Years ago I tested ASP under driven pulleys and DERALE twin 16" electric fans on the dyno. I don't have the dyno sheets anymore but the fans were 19RWH.P and the pulleys were 7RWH.P. If memory serves me correctly. There small gains but when added together they do make a difference. I know on my 07 Ranger, it ran 15.98E.T bone stock. I then added a CAI, electric fan and a ASP under driven crank pulley. The truck then ran a 14.67E.T. I got a huge gain from little in mods. Just to add it was much hotter the 2nd run with mods. In the low 90's compared to high 70's on the 15.98E.T run.

 

I got a set of UDPs from a friend who owned a 2001 with the 5.4. Does anyone know if they will work on my 2005 5.4?