Turning down alt pulley | Ford Explorer Forums

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Turning down alt pulley

colintrax

Elite Explorer
Joined
July 16, 2009
Messages
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City, State
Georgia
Year, Model & Trim Level
97 XLT
Instead of buying a new alt to get a few extra amps out of the alt, could I turn down the stock pulley to make it spin faster? Not sure what the max rpm is on the factory 130 amp alt.
Thanks!
 



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As I remember, there's not much material to really "turn down" on a lathe. But if you have a lathe, why not just make one out of aluminum - 60xx/70xx round bars are dirt cheap on E-bay.

IMG_1498.jpg
 






Cheaper and easier to turn down what I got instead of machining a whole new pulley.
Guess there really isn't much material to take off though :(
But something is better than nothing, 130 amps is probably enough but why not add extra :)
 






I'm gonna instal a deep cycle in the truck with a fridge (going on a trip)
Also going to put in a power inverter, which will be powering the fridge and possibly a heater. And I'm sure I'll be listening to the radio a lot with the truck not running, so dual batts is a must and I'd like to get em charged as quick as possible.

http://www.ebay.com/itm/1-4-5-X-2-7...134?pt=LH_DefaultDomain_0&hash=item27ccb363ee
Hmmm, maybe I'll make one
 






Don't make, or put on a smaller pulley on the alt to "make it produce more power", It simply wont, it will make SLIGHTLY more at idle, but that is about it. At higher engine RPMs you can overrun the Alternator, and destroy it. So if you plan on buying a new one anyway make you pulley smaller, or just save you money and buy a Mechman, DC Power, or other new alternator, and get high quality, and more power, without the headaches.
 






^I know I can over spin the alt, I wanna know what the max rpm is so I don't. I would assume theres some extra revs I can use. I just need to know if it's 200 or 2,000
 






I honestly don't know for sure. but just think of it this way, don't you think that the designers who mad it would have made it the smallest size, without destroying the alt? I mean a smaller alt, that makes more power, is a car companies dream. plus if they could save weight, they would. To be honest with you, I have a stock 130 amp alt on my Ex, I run my subs at full blast, my Hella 550 off road lights and CB on all at the same time, and I only have a slight dimming issue, this is also with the headlamps, and every other thing one, including the heater, and wipers. I think you will be fine with what you have, but if not, you may be able to get away with temporarily make the pullet smaller.
 






Well max load would be just starting, after sitting all night. So 2 low batteries, running at idle, with headlights, fog lights, cheapo headunit and 1 10" sub, heater, cell phone/computer charging, fridge running, and maybe some breakfast cooking :)
Definitely a load on the stock alt, but I think it'll be alright. I'll just turn it down like 1/32" or something small and hope all is good.

I'm guessing I have some room, since the SOHC uses the same alt and spins more rpms than my lil old OHV
 






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