blown 87

Has any body ever tried to increase the out put of the stock Bosch alternators?

I talked to my alternator guy this AM and he said he may be able to rewind the stator to get more amps, just wondering
if anybody had tried this.


Mine went south this week, so I stuck the spare in and it works now.

I never did trust the voltage gauge, seems to read just a tad low, but now I have a accurate digital gauge on the car
voltage really is while driving.

It will drop below 12.5 when the lights are on and the blower motor is on 4, plus I have the big amplifier in the car,
so I need more amps.



Greg Nettles

hacker-pschorr

Go big or go home:

blown 87

Wow

S4ordie

Greg - looked into this about 6 mos ago and found not many options other than a different alternator alltogether.

As my car, when it is finished, will have considerably increased electrical requirements, I need a higher output alternator that outputs much higher than stock amps at low rpm. I think about being in stop and go traffic at night in a rainstorm running 7" AV screen, stereo, wipers on high, .... The engine RPMS will be low and I don't want my battery to become drained.

The best option I found (never did locate anyone who could rebuild the stock alt to any significant output gain) is through Mechman. I believe this is the same alternator company Carl uses for his aftermarket option.

http://www.mechman.com/alt.htm

For now, unless you find someone who can rebuild the stock Bosch unit with significant low RPM output gains, this is what I will be putting on my car.

Lizard928

Why not put uprated bearing in it and change the pulley size to spin it faster at idle to increase the output?

V2Rocket

what kind of fwd car needs that much juice?


i like how theres an idler thats not even used

blown 87

Even at 3 thousand RPM, it still is low on voltage with all the electrical consumers on.

I do plan on putting the best bearings my alternator guy can get and will ask him about trying to find a smaller pulley.

EDIT: got any links to a uprated bearings?

blown 87

The kind of car that you can hear the thump long before you can see it would be my guess.

worf928

Don't you then have a problem of over-output at high rpm? IIR (dimly) C, the smaller pulley theory was discussed and that was the conclusion.

blown 87

I would not think so, that is the job of the voltage regulator.

danglerb

Thumpers run lots of alternator power so they can keep the voltage up close to 15v for maximum amplifier output vs 12.5v off the battery. Outside of a spl contest its meaningless, but in a contest its substantial.

We have huge batteries, so no real need for anything but long term power usage, and even a 1000 watt stereo at full power should have an average power usage below 100 watts. Headlights, wipers, fan, etc. OTOH due have a high constant draw, but should be handled with a very modest increase over the stock alternator.

What I think often happens is that people try to compensate for poor electrical grounds and other basic PM issues that keep us from getting the full output of the battery by installing a bigger alternator. It does sort of work, but so does PM on the electrical system.

Giovanni

Greg, if you are just needing another spare and I will bring you the alternator from the 88 :-).

blown 87

Thanks Gio, I have a extra one from the 89.

karl ruiter

Somebody trying hard to make the eRam concept work?

jcorenman

It can be done, and is commonly done in the marine business for cruising sailboats who want a fast recharge time on large battery banks. Lestek is one outfit that rewinds stock alternators for Balmar, Ample Power and others who put their own label on them.

But nothing is free. Getting more amps out of the same size case certainly means more heat, which is what kills the marine hi-output units in my experience. But I think it is worse than simply more amps-- to get more windings in the same frame means smaller wire, and smaller wire adds yet more heat.

But if you are willing to add some cooling then I think it would work. There's already a cooling duct, just add an extra blower inside the fender to help push air into the alternator.

Spinning faster generally doesn't work because the rotor wants to disassemble itself at high RPM from the centrifugal force.