2001 4.0 Underdrive Pulley

[Blueox]

Quick question. Do I have to replace the center bolt? Can I re-use the existing one???

If I do, I gotta buy four of them. Four to a pack.

 

[mjonesjr]

You can reuse the factory pulley bolt.

 

[Blueox]

Thanks!

Thanks for the response.

 

[daniel3507]

what will a new pulley kit do for performance? i dont know much about them.

 

[paxlineman]

yeah could someone just quickly explain what they do

 

[mjonesjr]

They are smaller than the stock crank pulley so they reduce drag on the engine.

 

[coffee]

They also slow your alternator and water pump by 20%. If you do decide you want to iinstall one, you need to make sure to monitor your water temp on hot days while running your air conditioning. You will also have to determine if you can allow a decrease in alternator output without changing the alternator pulley at the same time.

 

[daniel3507]

if you change all the pulleys will you still need to worry about the alternator? im assuming you would still need to watch water temp even with all of them changed

 

[Fx4wannabe01]

stuffforyourranger.com sells an alternator pulley that speeds it back up to stock levels....

 

[daniel3507]

i was looking at their pulley sets. they have the 5 set but im not sure if the power gain would be worth the money.

 

[AllanD]

the idea behind underdrive pullies is based on several factors:
1)on the belief by the gullible public that the factory engineers
really didn't understand what they were doing when they chose
the pulley size.
2)on the gullibility of the buying public that the pullies will actually
save them power by spinning SELF REGULATING engine mounted
accessories slower won't simply change the regulation strategy.
3)On the FALSE belief that the power savings quoted will occour
ANYWHERE except at the engines power peak rpm, somewhere that
most drivers never go.
4)And the belief that the advertising claims are actually based on anything except the belief by the manufacturers of such items that nobody will be able to prove their claimes are lies.

Advertising in essence is about turning half-truths into complete lies.

the Alternator often takes MORE power to turn at a lower rpm
once underdrive pullies are installed than it did before.
because the alternator is self regulating it will automatically increase the field current to maintain it's target voltage, the rub is that to create that voltage at a lower rpm requires more force to turn the alternator.

the faster you spin an alternator the MORE efficient it becomes and
the cooler it operates.

the PS pump isn't doing squat most of the time because there is a careefully
designed valving system...

the water pump? well mabey, other than on a dyno, if you spent an hour
at the HP peak rpm you'd see a difference.

considering the ability of a 4.0 to generate heat I certainly don't want
to spin my water pump any slower...

Particularly since when creeping around at low speed is when an engine
in a 4x4 really heats up... you LOSE all "ram air" effects of driving down
the freeway at 70mph....

And this allows for the fact that my primary use of 4x4 is
to AVOID going "offroad" and much of the rest is getting
back to a road if I'm not on one....

Or simply not getitng stuck on a sandfilled two track somewhere
on a Wyoming sageflat

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[travisswett]

hehe

Nice ...

 

[AllanD]

Hey, the 4.0 4x4 truck I found in a juunkyard with 1" wheel spacers,
(that some other idiot took) a Hurst Billet Plus shifter and a LockRight diff also had a "Turbinator" throttle body spacer

I was actually going to take the TB spacer because I wanted to mount it to a plaque labeled "this is STUPID".. but alas... someone short circuited my fun.

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[Fx4wannabe01]

TBspacer = awesome whistle. well worth the $20 i spent on it used. its a 'poweraid'. lol.


I know that, according to ASP, the installation of the underdrive pulley on a '05+ 4.0L mustang, it states to achieve stock Alternator output, engine has to be running at least 850 rpm. Thats only 100 or so above stock. I'd say thats good enough for me or anyone that has as good battery on the truck.

I'm actually about ready to install one on my '01 4.0..

 

[AllanD]

If I ever want and "awesome whistle" I can stick a phillips screwdriver
through one of the rubber connectors between the pipes on the high
pressure side of the intake on my Saab.

That 60trim T-03 can howl like a banshee as it leaks air overboard.
thing sounds like Stuka Dive-bomber.

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