UnderDrive Pulley Questions

[Rayz2000Sport]

I am considering some improvments for my truck, and I have heard good things about underdrive pulleys. How involved of an install is required for an underdrive pulley (ie is it something that can be done easily with common tools, etc.)? What kind of gains have people experienced (horsepower, torque, gas milage)? Has anyone found any ill effects as a result of installing an underdrive pulley ( i have heard of charging issues, this would be very undesirable since I have just done work to my charging system)? Any information will be greatly appreciated and will definitly influence my decision. Thanks

 

[BrooklynBay]

AlDive has a couple of threads on this. He has a small pulley on the alternator from a company called Underdog. I think he had issues with the pulley size, so he had to use the small one. Another issue was with the water pump. I think he might have the stock size back on it. A different size drive belt had to be used too.

 

[aldive]

AlDive has a couple of threads on this. He has a small pulley on the alternator from a company called Underdog. I think he had issues with the pulley size, so he had to use the small one. Another issue was with the water pump. I think he might have the stock size back on it. A different size drive belt had to be used too.

Gee, I didn't know I had a press agent.

 

[carlover]

Ive used underdrive crank pullies on at least ten different cars and had nothing but excellent results. Some people say you will have crank issues, but if its properly designed and balanced properly you should never see any negative issues.

 

[aldive]

I am considering some improvments for my truck, and I have heard good things about underdrive pulleys. How involved of an install is required for an underdrive pulley (ie is it something that can be done easily with common tools, etc.)?

A UDP crank pulley is the best bang for the buck that you can do to your truck.

Installation is not too difficult; the hardest part is the removing of the old crankpulley/damper.

Take a look at http://www.explorerforum.com/forums/showthread.php?p=1377150#post1377150

Has anyone found any ill effects as a result of installing an underdrive pulley ( i have heard of charging issues, this would be very undesirable since I have just done work to my charging system)?

You might need to go overdrive on the alternator to maintain charging voltage at idle ( only ).

Take a look at http://www.explorerforum.com/forums/showthread.php?p=1406278#post1406278

 

[jah81592]

Fortunately the full charge is at 950rpm. If he is tuned I would recommend raising the idle around 100rpm anyway(which I do all my customers). Charging shouldn't be a problem. I currently run a crank pulley only and I don't have any issues to date. This is with the stock current draw+ electric fan. Definately if you are looking for the highest hp and torque available crank pulley only is the way to go.-j

 

[CDW6212R]

Ditto, the balancer removal is the hardest part, plus holding the flywheel still to turn the crank bolt.

The 5/16" bolts included in most balancer pullers are too short. At least 3.5" bolts are needed, most kits come with 3.0" bolts, and hardware stores don't carry those longer sizes(fine thread).

Start by finding those longer puller bolts, and buy a new crank bolt from Ford, $5 or so, they are not reusable. Good luck,