can you run an underdrive pulley with an electric fan? or would that strain the alt.?

 

if you have the heavy duty alt. it should be ok. only problem i had with my fullsize was everytime i came to a traffic light i would have to feather the pedal to keep truck from wanting to stall. and forget it with the a/c on. they are fine in constant driving but suck in stop and go.

 

Wait, you have a UDP?

 

Joe, notice that he said "with my fullsize"[8D]

For a street driven vehicle I really don't see the underdrive pulleys being worth the hassle, especially with the issues superdak mentioned. Your alternator doesn't put it's full load on the engine unless it needs to anyway, turning it slower is just hurting it's ability to do it's job.

 

I've heard the upsides to the UDP, but the downsides is what keeps me from buying one.

 

Wait... what is a Underdrive Pully and what does it do and what are the pros and cons...

 

tell me too!! thanks

 

Here's a picture of an UDP. It connects to the crank and powers your water pump, a/c, alternator, etc.

The cons to that is when you add the smaller pulley, you don't get the things to work as well, such as the a/c, and altenator.

The pro would be that you free up some power.



[IMG]local://upfiles/19913/EF954CFB36734222A85FF160AB9B719B.jpg[/IMG]

 

Would it be possible to put a slightly larger pulley on the alt ? That should make up the difference.

 

yea, but the best case would to be buy a smaller belt and bypass the a/c unit when it gets cooler out.