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Old 11-11-2001, 12:12 AM   #1
mick dundee
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Question Under drive pulleys

I am looking into buying a unorthodox racing UD pulley. However, I am bit concerned about this being safe for the motor. I read on the ENDYNE website a while back that when you replace a regular crank pulley with an under drive pulley, you are essentially omitting the vibration dampening for the motor. Therefore in the long term the engine will literally shake itself to pieces. Is this the case with the EJ25 or not? I did a search and someone said that the EJ25's crank pulley isnt a vibration dampening device. Im in the dark here..................
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Old 11-11-2001, 12:57 AM   #2
ImprezaRS dot com
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The general consensus is the Subaru boxer engine (flat four) does not need a harmonic dampner and replacement pulleys are safe.

However, the under drive pulleys mean the alternator and the AC will not have enough juice. Since 85% of the gains from a pulley are due to less weight, and for each 1lb lost off the crank the car will accelerate like it has 2.7hp more, the lightweight normal sized pulleys are the way to go. They also mean the belts fit right.

Take a look at www.ImprezaRS.com/product2.htm#pulley for a set that replaces three pulleys and losed approx 5lbs. There is a single pulley available for less on the www.ImprezaRS.com/shoppingcart.htm page.

Larry
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Old 11-11-2001, 01:00 AM   #3
Kevin Thomas
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Default Re: Under drive pulleys

Quote:
Originally posted by mick dundee
Im in the dark here..................
Maybe I can shed some light then. Bottom line is that there have been many people (including me) that has had their pulley on their cars for a long time and none of our engines shook itself to pieces.

So, are you going to get a pulley?
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Old 11-11-2001, 01:06 AM   #4
mick dundee
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thanks for the info, Im gonna order one
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