So, Im installing the aftermarket pulley set, and I have mixed answers about the pulley for the Alternator. I have been told it will not perform well since I have a 12" sub, 350 Watt amp, than on the other hand other guys tell me it wont run my alternator will be just fine.

Any info would be great!

 

think of it this way your alternater puts out 110 amps at 1000 rpm give or take, and your amp is pulling 20 amps and your other acc. are pulling like 50 amps with all your lights on and the smaller pully you could be maxing out the alternator, you lights will dim everythime the bass hits ec., or it may be fine you wont know till you try it and if it does fry your alt. buy a larger alt like a 130 or 150 amp, some of the F-150 came with the 130 amp like mine did but i think it cames with the towing offroad package, good luck

 

well if you put pulleys on, and you do install the alternator one, buy stock in alternators, you be installing one every other month.

no matter how big your alternator is, all the ratings depend on how fast you spin it. a rating on the box is jsut a rating on the box, its a peak value that the companies determine by spining the thing at 8 million rpm. you can shop around and find one that has a real rating with a rpm number that its rated at so it will give you an idea.

underdrive pulleys slow down all belt driven devices to free up horsepower. think of it as gears on a bicycle. and you are going up a huge hill. your system is that hill. you are the alternator pedaling. the top of the hill represents the alternator recharging your system and still powering your electrics.

now which way will get you up the hill faster? harder gear? or easier gear?

cresting the hill slower = dimming headlights.

kind of a wierd way of putting it, but hopefully you get the idea.

 

I installed a set of MAC pullies on my '94 Mustang. The drop in voltage at idle was quite dramatic. I have had them installed for 5 years now, and never replaced an alternator, and the alternator in my 'Stang is out of a V6 car (Long story not for this forum). The draw is even more severe when I have my electric fan running (30 Amp draw). I can swicth it off from the dash - for stop lights when idling). think I'm getting what I paid for.

Steve

 

I recently bought a MAC 3-pulley set off ebay. There has been a noticeable drop in voltage (looking at the gauge) when the a/c is on "max", fan on "high" and the headlights "on". I expected the drop but feel it is neglible enough to not worry; I don't have that much in-traffic driving anyway.

 

why even use the alternator pulley there is no power loss there its not continually drawing and its one item u dont want to under spin unless u want to set ur idle to about 800-900rpm

 

I think its best I dont even use it. Maybe if later down the road if I decide to purchase a new more powerful alt? Would that help at all?

 

in my opinion i dont think you will have any problems, good luck in whatever you choise

 

The alternator pulley that comes with under drive pulley's is actually an overdrive pulley to help compensate for the underdrive crank pulley. By not using the alternator pulley that comes with the pulley kit you are only making the alt. spin slower.

Casey

 

I just checked the specs on my truck with the FX4 package I have a 130 Alt. I think I think I will be ok. Thanks for all the info!