I love to research products before buying and I usually get to the bottom line of what I want but I am a little confused on these pulleys. Troyer supposedly has a good 2-piece set and I've heard others say that they have had good luck with Summit's & BBK's 3-piece set. They go from about $150 on Summit's to about $170 on BBK's and up to $225 on Troyer's. I looking to get some real opinions from people who have them installed and get direct on what set is best for a decent price. I'd like your thoughts on other companies products too.

 

Can't speak for this particular one being used on Ford, but I've done numerous ones on GenIII GM V8s. This usually underdrives the parasitic devices being spun by the serpentine belt by about a 25% slower speed. A very good idea(which the manufacturers should employ themselves at the factory) because these parasitic devices all over spun and some are highly over spun. Take for example your alternator(a parasitic device). It goes into cutoff at about 1K RPM. When it spins over that speed there is no gain(between 1000 RPM to 6000 RPM) thus the underdrive pulley comes into play. The pulley slows down the A/C compressor, waterpump, alternator and PS pump. The benefits are: all those parasitic devices last about 25% longer since they are spinning 25% slower. The power that was wasted overspinning them goes to your rear wheels. The result is more horse power to the ground and some added fuel economy. Overall a very good investment. Both of my vehicles have them. It's one of the first mods I make as soon as I get a new vehicle home from the dealership.

 

I've heard a lot of explainations how these pulleys work and the benefits from them, I'm just trying to find a brand to go with at reasonable price and either a 2 or 3 pulley set. Your explaination is by far the best I've heard. I really would like some direction on a brand and why I should go with them. My truck is starting to get high in mileage and I need all the benefits I can get.

 

They obly give a few hp gains and nothing that you will feel. The gains are mainly up about 4000rpm and up.
Some possible side effects are poor charging at night at an idle due to the load of the lights and such, and sometimes overheating at low rpm if the cooling system is weak.
I would invest in a programmer such as a Diablosport Predator if you want some really noticeable gains.
Not much bang for your buck will pulleys on a lower rpm engine. Had them on my 5.0 Mustang. No noticeable gain.

 

I don't know what is available for Ford, but the other brand has a bunch available in the $200 price range. You can get some dimming of the lites on your dashboard at nite in the summertime with the headlites, radio and A/C turned up to max. while stopped at a red lite. That's a small price to pay for the gain. I haven't seen it adversely effect cooling, but then how would I know about that since I run the Meziere elec water pump which saves an additional 10 hp. The manufacturers claim about a 10 hp gain from the underdrive pulley. He's talking about a bolt on item. If you put on a CAI, 25% underdrive and electric water pump your going to feel the difference. Will it be a 30 hp gain? You'll need dyno time to prove or disprove that. I believe Diablo is a handheld reflash unit as is Hypertec. These units give minimal bang for the buck considering that for a few dollars more you can get a full blown mail order reflash or buy some dyno time and have the reflash done there at the speed shop. I don't know what aftermarket speed stuff is available for the 5.4 V8. I spend too much time changing coil packs on F150s and Expeds to find out. The other brand doesn't seem to have this coil issue so I spend the money I make fixing Fords on speed parts for the other brand.