Aluminum vs Steel UDP sets, which is better?

I have the BBK's and like them so far. However, I hear the Steeda pulleys aren't piggyback. In hind sight I would go with the Steeda.

As far as I have heard it's just a matter of cost.

cougar694u said:

I noticed a lot of people swear by the steeda pulleys. Aren't these steel, or am I wrong? Wouldn't aluminum pulleys be a better choice? I'm asking because I've found both steel and aluminum pulleys. Instinctively, I'd go for the lighter ones if the ratio is the same. Do you guys know something I don't?

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You'll have some serious issues with the aluminum. Now, that said many people run them just fine with no problems.
What you want is a mass on the front of the crank as close to stock as possible with a properly tuned damper material. In a perfect world this will even be SFI approved too.

It's your oil pump and potential rebuild. I'd go Steeda or SHM or stay stock.

A lot of people do the PS and water pump pulleys and leave the stock crank pulley in place. This works well too.

cougar694u said:

Such as?


How does it affect the oil pump?

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Many, many people have blown engines as the oil pump is very fragile and if the harmonics of the engine aren't cancelled out correctly, the oil pump gears break.

Search for it and you'll see all the details.

cougar694u said:

How does it affect the oil pump?

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Having the appropriate mass in a pully (steel) with the addition of a damper helps take some of the ring out of your crank... you know, vibrations that change in frequency with the RPMs and will set up a potentially damaging harmonic at certain speeds.

Harmonics are vibrations that increase in amplitude as the pressure waves overlap and add to each other. For a demonstration; hold a poorly balanced variable speed drill against a light yet solid table with a glass set on top. Watch as you go through the RPMs how the glass reverberates more at certain speeds. These will be your harmonics.

Basically, you start rattling things around more violently at particular speeds, and over time that can cause premature wear. A heavy damper absorbs more of that energy (like putting your hand against a bell to quiet it).

Our engines are not terribly unbalanced, but they aren't 100% perfect either (nothing is).

So, pick your poison... gain maybe a HP or two and slighly freer reving by doing away with the heavier damping, or leave it alone and let your rotating assembly potentially last longer.

Some folks address this rotating mass issue by going with a lighter flywheel assembly. You can shave off a little more weight there without reducing the mass on that end too much (but there are other consequences).

Hope this helped.