alternator with od pulley at high rpm
 

Basically, I'm wondering if I need to switch over to a 145A alternator for future use of e-fans or can just stick with the stock 105A alternator and stick on OD pulley on it.

All alternators are rated to a certain maximum rpm, so my question is can the stock alternator with an OD pulley survive when spinning the engine up to 6k rpm levels??

I am looking to get a BlackBear tune and thought about picking up his e-fan harness and alt OD pulley at the same time, but then this questions popped up. I don't know the max rpm levels of the stock alt, but I don't wanna burn a bearing in there.

i have a OD pulley on my stock 105A alternator and I shift at 6900-7000.... No problems, at least for me :)

If this helps, tdrumm was running 05 efans on his old 5.3 rcsb with the 105 alt with no problems. He also had an underdrive crank pulley, not sure if he had the alt pulley or not...

alright, thanks fellas. I'll probably just grab the OD pulley and slap it on the 105A alt and go from there.

I upgraded to the 150 (if I remember correctly). I have upgrade UDP to smaller than stock, and I have e-fans. No probs here.

Added the e fans several weeks ago, haven't found the 145 alt for the price that I want to pay. Works fine still, but you can watch the volt gauge drop some when the fans come on. The od pulley should work fine, because I have spun the motor up just a little and seen no volt drop. I am still going to do the bigger alt when I find one.

did anybody have a need to swap out to a slightly longer belt after the OD pulley install? I'm hoping not and that the tensioner pulley will just give a little...

My truck hated my original 192,000 mile 105 amp alternator and electric fans. I could see and hear a change (blower speed) when the electric fans kicked on. I checked it before it died and it was only making like 30 amps under load at idle. I replaced it with an Oreilly reman 140 amp CS144 alternator for 125 bucks. Now there is just a slight dip in voltage as the fans come on but after that it stays right at 13.8-14 volts reading it with a DVOM.