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Underdrive Pulley?

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Old 05-25-02, 07:20 PM
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Question Underdrive Pulley?

With all my mods up todate, I am thinking of getting an Unorthodox Main Pulley.
I know the advantages of having one, but In relation to our FC's, would this be a wise Investment?
I am running a powerful Electric Fan (Black Magic #150) and believe It or not all new cooling related sensors so I am not really worried about my FC overheating.
Does anybody have an underdrive pulley set up?
What Is your opinion of having one? (Doesn't neccesary have to be an Unorthodox one).

Thanks Guys.
Old 05-25-02, 09:34 PM
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I have one.. Other than worrying about if the timing marks are correct, no problems with it. Mine's the 2 belt Racing Beat one.

My concern would be, in your case, electrical load at low RPMs, others probably want to comment on that (my car has almost 0 non-essential electrical devices)

PaulC
Old 05-25-02, 11:31 PM
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I should also mention that my electric fan sucks a considerable amount of amperage. I think 13.9.

That with my headlights on (H4 - PIAA Super Plasma White) drops my volts down.

But well above the 12v point. So I guess you could see my point of concern.
Old 05-26-02, 06:20 AM
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Unless your car spends most of its time at high rpm (i.e. it's a racecar), underdriven pulleys are a waste of time. The only noticable power gain will be at high rpm (and you'll need a dyno to "notice" it) and it'll only be a couple of hp. Your already undersized charging system will lose 10-20% of its capacity (kiss your battery goodbye with that fan) and so will your water pump.
Old 05-26-02, 02:24 PM
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Also, removed A/C. So that Is one less belt running of my Main Pulley.
I agree, the fan sucks a considerable amount of amps esp. when I have my headlights on. I plan on re-installing my stereo when I get to It. With the above applied, plus the underdriven pulley, Iam asking for trouble.
Better I stay where I am!
Thanks for your input.
Old 05-26-02, 02:46 PM
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Most of the gain you get from an UDP is the loss in weight. Not really the size of it. The loss in weight is what does it for you, rotating mass. I'm not sure what the stock pully weighs. Does anyone happen to know?
Old 05-26-02, 03:08 PM
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The stock Main Pulley weighs 4 pounds 7 ounces. The Unorthodox Pulley weighs 1 pound 11.2 ounces.
Old 05-26-02, 03:13 PM
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Just install an FD alternator with it and I don't see how you would have too much problems. I want to do that when I get my e-fan anyways.
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