Alternator pulley question.

[bobtodd]

If I have the stock crank pulley on does it matter if the alternator pulley is an underdrive? Will I lose juice(amps) or gain it? I would think I would gain it?....my brain doesnt want to work right now. Help me out :D

[Tom]

Is the pulley larger than stock? It will slow it down if so. The thing to watch out for is belt length. You may or may not have enough travel on your tensioner.

[bobtodd]

The alternator pulley is smaller than stock. Which will spin it faster I believe.

[ntastng]

Maybe I am thinking about this wrong but you have an underdrive pulley on the alt now which is smaller then stock. So It should still be underdriven regardless of the size of the crank pulley. Having a bigger pulley on the crank does mean that the accessories should turn a little slower then they did with all of the underdrive pulleys on, but it is still shorter then stock. I Honestly don't know how much of a difference you will see if any.

[bobtodd]

I guess I was just wondering wether it was worth putting the stock alternator pulley back on. I believe the underdrive alternator pulley is smaller so I am going to keep it on.

[1slo5.0]

If it is an underdrive pulley it will be larger than stock. The crank pulley in an underdrive pulley set is the only pulley that is smaller than stock because it is the drive pulley. You will be ok with an underdrive pulley on the alternator. They are not much bigger than the stock pulley. The charging system will be ok and the belt will be fine.

[bobtodd]

Thanks Dan. I just dug the stock pulley out of a box and there isnt much difference like you said.

[bobtodd]

Doh...I meant Darrel.

[1slo5.0]

Doh...I meant Darrel.



Dan's crazy, I'm sane.......you should be able to tell us apart pretty easy :D

[bobtodd]

When you make the big bucks at the railroad like Darrel does then you can break stuff and not worry about it. Those conductors/engineers have money to burn :beer: :D

[1slo5.0]

Yup. Thats what any normal, levelheaded, SANE person would do!!!!

.........uhhhhhhhhhh.......What's wrong with that????? :p



When you make the big bucks at the railroad like Darrel does then you can break stuff and not worry about it. Those conductors/engineers have money to burn :beer: :D


I don't work at the railroad anymore. I work a normal persons job now and sell parts/fill nitrous/sell race fuel on the side to keep me busy. I gave up the big dollar railroad life for a normal average Joe family life. I am much happier now.

[ntastng]

Sorry I was picturing my old alt with the underdrive on it vs the 3g that I just bought. The underdrive is a lot smaller then the one that was on the 3g.

[bobtodd]

Yeah, I just went out and checked the car today. I've got the 3g also and the underdrive is smaller.

[Tom]

Depends on kit, I think. If the ratio to the crank is really different a smaller pulley can still allow it to be underdriven.

[ntastng]

Dan I am suprised you didn't notice that when you had both of mine out at the shop. my underdrive is about the same size as teh stock one but it is smaller then the 3g one.

[1slo5.0]

94-95 5 liters have a different underdrive pulley kit from the 87-93 5 liters. One of the differences is the size of the alternator pulley because the 3g alternator pulley is bigger than the junk that comes on 87-93 Mustangs.