Steel Underdrive pulleys vs aluminum?

[mob]

Is there really a difference between steel or aluminum besides the probable .5 weight difference?

 

[Wallzy]

If they are the same dimensions then the aluminum will drain less power - might be im-measure-able though:

T=angular accerlartion*inertia
HP = T*RPM/5252

Walz

 

[mob]

Why do they drain less power? Because they are lighter? I see the equation but it doesnt explain why it drains less power. I guess im just trying to ask are they really worth twice the price?

 

[aar0s]

the ones i bought on ebay were only like 10 bucks more. i didnt get a chance to weigh them but they seemed a bit lighter than the stockers.

 

[1991notchbackLX]

i'm sure there's an argument to be made for rotational mass/parasitic drag somewhere, but you won't hear it from me concerning such small disparities in weight, diameter of the pulley is what you should be concerned with, in my opinion

 

[mob]

thanks thats what I figured

 

[Wallzy]

If they are te same dimensions and the aluminum one weighs less then it will have a lower moment of intertia. If it's interita is lower it will require less torque to accelerate it and horsepower is a function of torque and RPM, but in my opininon it will be in the noise.

Walz

 

[93tealstang]

i'm sure there's an argument to be made for rotational mass/parasitic drag somewhere, but you won't hear it from me concerning such small disparities in weight, diameter of the pulley is what you should be concerned with, in my opinion

I couldn't have said it better myself. From experience, I've ran both only noticed one thing. The aluminum's wear much faster than the steel's, mainly the water pump pulley. It wore very thin over time and caused me to ditch the whole set in exchange for steel's.

 

[mob]

thanks 93teal for that info

 

[Mustang78]

wear is the only issue i know of, i went with aluminum BBK's because of quality and looks.. they dont come with a PS pump pulley though FYI, i run a flaming river manual rack so its not a problem. I will always buy aluminum for no other reason than looks, steel work just as good but dont look nearly as nice, my BBK water pump pulley is in a box now because i had to buy a ribbed pulley to keep the belt from slipping on the smooth one(because i run from crank to water pump, to alternator then back to crank...) PM me for more info

 

[dcurtis]

After seeing this thread I say steel
http://forums.stangnet.com/777990-pully-ripped-half.html

 

[mob]

Damn nuts, never having researched this I would have thought the aluminum's would have been better because their half the price. I guess its just all looks. Thanks for the info guys, I am defiantly going steel when I get my 3g and electric fan on.