High Output Alternator Question

[Kidasters]

OK guys - I went and purchased the "80 amp high output alternator" from bnrparts on e-bay. Got it in the mail today, and now I have some questions. I've asked these same questions to them, but wanted to see what the consensus of the group was.

I pulled out my spare alternator mount, and indeed, it will fit - so I'm confident I can bolt it to the block at least.

This alternator doesn't appear to have a place to put bushings. Does that seem like a problem?

The blue wire in the picture on the D+ post plugs into the "D+" terminal that used to go to the voltage regulator. The E-bay seller then says that the other "Post" (I'm assuming the "B+" post) goes to the battery. That seems to jive with the E21 alternator instructions in the FAQ.

There are no instructions about running a ground. That doesn't seem quite right. Unless this thing is grounding through the body because there aren't any bushings. Hmmm.....

What do you all think?

Ken

[canadapierre]

Amazed that it fit in that FedEx envelope. Must be that new inflatable type alternator ; )

[icebox]

I'm no expert but,,, LOL , . I read in one on the 2002 books that the factory alternator bushing is a poor design , or weak point . When worn it can cause the alternator to lean and the belt to slip . It was recommended to replace the soft bush with a metal bush . After this is done it was noted in the book " It will then be self grounded , "SHOULD" be no need for a ground wire " ... Hope that helps .

[Kidasters]

Amazed that it fit in that FedEx envelope.

Ha ha! You know - after I took the pictures, I knew someone would say that . Actually - we just had the table re-finished. Momma would kill me if my new fancy alternator scratched it.

Ken

[H_Krix]

the alternator does ground through the mounting point, but I'd go the extra mile (which is what I'll be doing with my car) and pick a bolt on the casing of the alternator to attach a ground strap to.

If the hole beneath the resistor in the last picture is threaded, I'd use that. Otherwise, maybe use the bolt that the resistor mounts onto the chassis with.

[lazerfred]

Hey! You're doing what I was thinking about doing... maybe you or others can answer my questions too...

I've got a 72 2002 and I replaced the alternator last year with what had to be the world's worst 45 amp alternator. Suffice it to say it just does not generate what I need because (I assume) of the combo of my stereo, sirius satellite, nav unit, etc.

Anyway, I thought about getting one of these higher amp alternators, but I'm really, embarrasingly, dumb about adding stuff to the car. If it's anything other than a straight swap, it's a bit freak for me. That why I'm avoiding the 80 amp solution at Zenon Holtz's wonderful site: http://www.zeebuck.com/bimmers/bmvseite/

He implies that using the E21 upgrade involves a "simple wiring change". Is that what you're doing here? What is the simple change? Is the source you got your alternator from a reliable source? Do others have a suggestion for a killer high amp upgrade that is as simple as possible?

Thanks so much!

[JohnC]

Anyway, I thought about getting one of these higher amp alternators, but I'm really, embarrasingly, dumb about adding stuff to the car. If it's anything other than a straight swap, it's a bit freak for me. That why I'm avoiding the 80 amp solution at Zenon Holtz's wonderful site: http://www.zeebuck.com/bimmers/bmvseite/

He implies that using the E21 upgrade involves a "simple wiring change". Is that what you're doing here? What is the simple change? Is the source you got your alternator from a reliable source? Do others have a suggestion for a killer high amp upgrade that is as simple as possible?quote]

Zenon's instructions are "as simple as possible". Sorry, it just doesn't get any easier. Just do what he says. Really, I'm not exaggerating! Jump in and do it, you won't regret it.

[Kidasters]

Well - maybe I'm an idiot in more ways than that (as my wife would probably agree too). My fog lights are still not wired in, because I'm to intimidated to run the wires and the relay. Anyway, pulled this out of the box, and it seems pretty straightforward. I think if I felt like draining the radiator and pulling it, I could probably do the swap in a few hours. This looks like a pretty simple swap. Of course, my exaust manifold looked like a pretty simple swap, and that was a nightmare.....

I say go for it! Especially if you are already having issues.

Later,

Ken

[lazerfred]

OK guys --

I'll give it a try... wish me luck!

[ifayeoh]

Please post results once you get that installed, i may have to try that.

[lazerfred]

It'll be about two weeks while I track down parts; but when I do I'll take pictures and/or video, which might either be helpful to all, or humorous, depending on how badly I mess things up!

[kaptanoglu]

Kidasters -

 

How did that BNR Parts alternator work out?  I am doing a resto on a '74 tii, and am looking at the same thing.

 

Thanks,

J

[mdh]

I've had one for a few (6) months and it has bee working out pretty well.

[Chris_B]

I dunno about the bushings and mounts on the alternator that they provided to you. Seems like not having soft (rubber or even plastic) bushings might increase the NVH quotiont of your motor. In any event, the biggest difference is that this unit has an internal voltage regulator- thus the reason that the D+ wire (the blue one...) connects directly to the alternator. I agree that an extra ground between the body of the alternator and the motor (using at least 10 awg wire) would be a good thing.

[mikesmith]

For the ground wire to make sense, it needs to be the same size as the wire that you run from the B+ terminal, since its effectively in series with that wire.

10ga is on the low end of reasonable; at 1mOhm/ft you will drop 40mV at 80A over a 6" wire jumper from the alternator to the block, and dissipate 3.2W, which will make your wire quite toasty.