morbid

why wouldnt you want UDP's with a stereo system or supercharger

04BlueGT

superchargers produce big heat so having the water pump turn slower is bad. If you have a BIG watt stereo, same thing with the alternator. Plus, with the smaller crank pulley, your sc will turn slower, too.

macdaddyslomo

Actually i looked it up, because I am new to Mustangs, but not UDP's http://www.mustanghowto.com/engine/UDP/UDP.htm

you're statement isn't true...UDP's REPLACE the stock pulley...if you piggybacked some but not all, that would cause belt walk

JonBeast

It wouldn't be any fun if they did[8D]

04BlueGT

You're not understanding me. Steeda is NOT piggy back (you're correct here), but is steel. Got them on my car. Some March udps are piggy, some are not and have the sfi approved damper (in steel). MAC, that useless crap, is piggy back aluminum. I had them and now they are in my basement, one still mated to my stock crank pulley.

Again, the weight is insignificant for UDPs.

macdaddyslomo

Even in steel, a UDP is going to be LIGHTER...it's SMALLER

and if you think reducing the weight of the rotating mass is insignifigant, you are mistaken

Monch

that is not correct, the MAIN part, being lighter certainly helps but is secondary.

remember your first 10 speed, or whatever mult-speed bike you had, when you went up a hill you switched gears to a higher ratio, it made it easier to get that bike and you up the hill, but you went slower. underdrives to the same thing, coupled to the pulleys are the rotating shafts of all the accessories. everytime the engine changes speed the accessories must change speed. the combined weight of the rotating shafts are much heavier than the pulleys. it take less crankshaft power to change their speed when underdriven.

the reason ford doesn't use underdrives is two fold

1) manufacturing concerns of the 4.6 - its easier & cheaper to use the same accessories across all product lines.
2) reserve capacity. over time your cooling system, alternator, power steering pump get weaker. there has to be a safety factor so the majority of people who don't baby their cars like we do still get the reliability they need across all types of driving conditions. we can get away with it because we are highly likely to keep our cars in top shape.

redfireshaker06

I have underdrive pullies w/ a system. No problems for me..

04BlueGT

I'm so done with this thread. I think Ron White was right.

macdaddyslomo

That's cute...a simple debate turns into: "If you don't agree with me, you're stupid"