70 MACH I

Used my AC yesterday, it hit 87 degrees here. First time I've used it since installing the Steeda UDP's, my AC was icy cold and I didn't feel the compressor cycles tax the engine like I used to. I don't understand why Ford doesn't use them as standard equipment, I'm sure they improve fuel economy.

John

n/a_threat

Good to know, thanks for posting. I wish Ford did a lot of things like the pulleys and a lower ride [:@]

TeeStang

Thanks for the info. Im probably gonna get some Steeda UDPs once i get a little extra cash.

macdaddyslomo

A little O/T, but can you just get LIGHTWEIGHT pulleys for the 4.6, rather than UD ??? Less rotating mass would still be less parasitic loss

monkeydude3

light weight wouldn't make as big of a difference, and yeah I too wonder why ford didn't do a lot of things.


Ford, doing things that would make sense? ha! [8D]

VARifleman

Once they get spinning, it's no longer parasitic loss due to mass. Changing the speed of them loses a little, but most of the problem comes from turning the accessories faster than they need to.

macdaddyslomo

Once they get spinning ??? Once they get spinning who cares if you have 50hp or 500hp ??? It doesnt take lots of power to MAINTAIN a speed. Reducing the parasitic loss allows for you to see more power at the wheels....The MAIN reason UD pulleys will show a gain is the fact they are MUCH lighter than stock...underdriving them usually causes unwanted problems

VARifleman

I'm talking about once the damn pulleys start spinning. And if you think it's just because they are lighter, you have to think, what's taking more energy to drive, just overcoming the pulleys moment of inertia, or the fact that putting larger pulleys on accesories, since they require less torque, require much less force because your moment arm is longer. Who on here, with UDPs, has a problem with them because they are spinning accessories slower? You're arguing with an engineer here you know...

macdaddyslomo

Engineer or not, you are apparently missing the point...regardless of inertia or not,the idea of UDP's is for more power, no ???Acceleration is the only time you NEED power !! A heavier rotating mass requires MORE power to accelerate, period. You dont think a lighter pulley will help past the initial spin ??? OK...you put 22lb 17 inch wheels on your car and I'll put 15lb 17inch wheels on mine...we'll start from a roll...assuming everything else is the same, who's do you think will be faster ?? The MAIN reason UDP's give you more USEABLE power is the fact that they are lighter. The underdriving helps too,but that can be an issue.

Need an example of someone that WOULDNT want UDP's but could use a lightweight pulley ??? Ask anyone who has a supercharger or a serious power audio system.

04BlueGT

Actually, UDPs work due to reduced circumference, not weight. Steedas and (some) March are steel, not aluminum. Aluminum is fine for the alternator and water pump, but suck butt for the crank - they are all piggy-back style. That means the aluminum piece is bolted behind the stock (HEAVY) balancer and then mated to the crank. You actually have MORE rotating mass than stock. Yet, you have less parasitic loss.