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Hey, I have a 95 Z71 with the stock 105 amp alternator on it. I added underdrive pulleys that replaced the alt pulley with a larger one and I added dual electric fans also that pull a total of 50 amps. When my fans come on my volt meter drops to around 8 and my lights get very dim. It has even cut off before while at idle for a while. I have been looking at the 200 amps that Powermaster makes. Would it be ok to put one of those on their? I do plan on adding a winch and off road lights soon also. Any help would be great. Thanks
 

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Hey, I have a 95 Z71 with the stock 105 amp alternator on it. I added underdrive pulleys that replaced the alt pulley with a larger one and I added dual electric fans also that pull a total of 50 amps. When my fans come on my volt meter drops to around 8 and my lights get very dim. It has even cut off before while at idle for a while. I have been looking at the 200 amps that Powermaster makes. Would it be ok to put one of those on their? I do plan on adding a winch and off road lights soon also. Any help would be great. Thanks
With a larger pulley on the alt it has to spin twice as fast as it did to make any amperage, So at idle it probably is'nt even turning on at all.Put the stock pulley back on or get an OVERDRIVE pulley for the alt.Most alternators need atleast 800-900 (pulley not engine) rpm. Slow it down, it will turn off.Now, 105 amp alt + Efans = :pow:powermaster makes great stuff, but no alternator is going to be good enough if its not spining fast enough to make any power.I build my alternators to make as much power as possible at idle. Large housing units(AD244) like what Twankydeuce and halfAhoe run, hit [email protected] idle and peak out just past idle.Hope this helps.
 

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Discussion Starter #4
Thanks RR, So do you think the 105 will keep up with the stock pulley or what would you recomend in this situation? Thanks
 

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Thanks RR, So do you think the 105 will keep up with the stock pulley or what would you recomend in this situation? Thanks
It might, but its like a band aid on a severed arm. Just a matter of time, its gonna die. xlcooplx had the same prob you have. He installed one of my overdrive pulleys alone, with good results.105 amp will probably work constant, and never turn off resulting in death.Its all depending on the alt/battery/cable condition. Anthony is right, but get an overdrive pulley(helps a ton at idle). If you are going to add all that stuff, get the biggest alt you can.If you use the winch alot(2-3 times a week).I also suggest dual batterys (parallel),your armature and brushes will love you. Plus, the life of the winch motor will triple.I would at the very least try on overdrive pulley and larger grounds and charge wire.Hope this helps.
 

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Discussion Starter #7
Thanks for the help. I wander if the 140 amp GM used on some of the 98 and 99's would directly bolt up and be good enough. Maybe still do the overdrive pulley too. Would I have to do anything with the voltage regulator?
 

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Thanks for the help. I wander if the 140 amp GM used on some of the 98 and 99's would directly bolt up and be good enough. Maybe still do the overdrive pulley too. Would I have to do anything with the voltage regulator?
No matter what alt you get, get the overdrive pulley.See the difference?The small unit has the overdrive, and the large has the stock pulley, which is the same for both units.It dosent look like it would make that much difference, but it dose! You will get 30% more amperage at idle.Yes, the late model alts will bolt right in.The ad244 has the same mounting dimentions as the cs130D and ad230 check the pic, The regulator plugs 95-current are the same 4 pin oval, except a few 05-06 Bosch units are 2 pin round.

100_0204.jpg
 

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where do you get the overdrive pulleys... and how much are they?
You cant get a rolled/stamped pulley that small, so I get them machined by the 100.My last bill was just over $1900, so they cost about 20-25 plus a couple bucks for shipping.This pulley and a big three dose wonders for our little anemic gm charge systems.xlcooplx said he seen 2 volt jump at idle with efans at idle.
 

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I also have charging issues with underdrive pulleys. I would be intrested in one of your smaller pulleys as well. Let me know how much shipped to 92026 and the best way to get you payment. Thanks Ratt
 

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ill be sure to look you up once i get my next vehicle
You didnt get rid of your Tahoe did you?:bawl:

I also have charging issues with underdrive pulleys. I would be intrested in one of your smaller pulleys as well. Let me know how much shipped to 92026 and the best way to get you payment. Thanks Ratt
I'll let you know monday.
 

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What's the deal I've seen with low voltage at idle with big amp alts?
 

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What's the deal I've seen with low voltage at idle with big amp alts?
Sorry for the book so here goes.

Rotor speed. When a ho stator is installed, the rotor coil cannot push the increased feild mass created by the stator unless you speed up the rotor or add more coil winding to the rotor to increase the rotor mass.Once you get above 200 amps and closer to 300 the problem gets worse.The stator and rotor winding has to be matched.Then by adding the overdrive pully, we shift the power band of the alt increasing amperage at idle.I can only get 80-90 amps at idle with a matched up stator and coil on the large housing Escalade alt. Add the over drive and my stuff jumps to 100-125 at idle.Then just past idle 700-800 engine rpm, Im pushing 240-260.:evil:
 

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Ah, physical case limitation. Gotcha.

Are there any internal regulators that are adjustable for idle voltage?
 
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