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Discussion Starter #1
Ok, so I see that alot of people have installed aftermarket underdrive pulleys. I have a couple questions, since I am not a motorhead by any stretch of the imagination;
1. What is the benefit?
2. How difficult of a mod is this?


Thanks!
 

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an underdrive pulley kit will do 1 or 2 things to make power. First, it will (as it name implys) underdrive belt driven accessories, which frees up hp/tq by causing less parasitic drag on the crank. 2nd, most of the after market crank UDPs are lighter than their OEM counterpart, and by removing that weight frees up "Rotational Mass" which in turn lets more power go to the wheels.

Dificulty level is tricky. How's your mechanical ability?
 

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Discussion Starter #3
I am pretty mechanical... and can follow good directions.
I couldn't just sit down and do it without directions though
 

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Mr Know-It-All
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I would counter than not a lot of people have swapped out their UDP on the Duratec. A few who I can recall that did, did not have a working engine when they were done.


There are other things you can do to make similar power gains. I would save the UDP till last or have someone who is qualified and has the right tools and experience do it. If you screw it up, it's definitely not worth it.

>8^)
ER
 

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DoubleStuf™
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My understanding is that the difficulty level isn't THAT bad, it's just that the risk is PLENTY bad enough to make up for it.

The crank-shaft isn't keyed, so if you undo the bolt holding the pulley, and the crank shaft then turns & you don't realize it or get it exactly right on reassembly, you'll need to rebuild your whole engine because the pistons & valves will collide the first time you try to start your engine.
 

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Official [FJ] Distinguished Advisor
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The Oreonic device is correct.

Bad things can happen. Not worth it for a street car.

You'll realize a far greAter reduction of parasitic drag with a BS delete if you have a D23.

Benny's description of slightly measurable benefits is entirely correct, though.
 

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DoubleStuf™
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"Oreonic device"??? WTF! I feel like such a tool.
 

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Certainly did not intend to make you feel like a to0l.

My apologies.
 

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Certainly did not intend to make you feel like a to0l.

My apologies.


Tools can be painful.

In my mind a nice light weight pulley set that would allow the engine to rev up quicker, and not nessicarily show big gains on the dyno would be ok.
 

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In my mind a nice light weight pulley set that would allow the engine to rev up quicker, and not nessicarily show big gains on the dyno would be ok.
And wouldn't slow your water pump or alternator, making it a good choice indeed.
 

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In my mind a nice light weight pulley set that would allow the engine to rev up quicker, and not nessicarily show big gains on the dyno would be ok.
And wouldn't slow your water pump or alternator, making it a good choice indeed.

For a streeter.
 

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In my mind a nice light weight pulley set that would allow the engine to rev up quicker, and not nessicarily show big gains on the dyno would be ok.
And wouldn't slow your water pump or alternator, making it a good choice indeed.
Smaller crank pulley + bigger water pump pulley means water pump spins just as fast per rpm as it did before. The alternator and other accessories spin slower.
 

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Sure. But the kit doesn't come with a bigger water pump pulley.
 

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DoubleStuf™
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You mean Smaller crank pulley & SMALLER water pump pulley. You have to keep the ratio the same.


"Ladies!! You need more than a man! That's right, you need a tool- a POWER tool! Get all your pleasures, find all your wildest dreams with the BIG O...reonic device! Let OREO put the CREAM in your chocolate cookie!"
 

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You mean Smaller crank pulley & SMALLER water pump pulley. You have to keep the ratio the same.


"Ladies!! You need more than a man! That's right, you need a tool- a POWER tool! Get all your pleasures, find all your wildest dreams with the BIG O...reonic device! Let OREO put the CREAM in your chocolate cookie!"
 

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good lord what have i done...
 
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