Wiring up a new alternator?

[Anthony]

So my new to me race car has no provision for an alternator which is something I would like to rectify. What is the easiest way to re-wire an alternator into the electrical system.

Car is gutted race car no factory harness remains.

I was thinking of ditching the BMW alternator and hooking up a 2 wire AC delco unit which would be cheap and easy + to battery - to ground, internally regulated.

Any ideas?

Anthony

[Beaner7102]

Check out Zenon's site

http://www.zeebuck.com/bimmers/bmvseite/

Tech section - Installing a 318i 80 Amp Alternator, that'll give you a clue on the wiring side of it. You could use a 45amp Alt from and E21, wired as per write up. No need for the 80amp on a race car. Beaner7102

[Chris_B]

You can indeed use a so-called "one wire" GM alternator. That one wire is the + output from the alt.; ground is typically provided through the mounting, or can be provided by a separate wire. These alternators have self-exciting field coils, so do not need the third wire in the 02, which serves the double purpose of providing the +12V (D+) to excite the field coils when you first spin up the alternator, and provides the charge indicator in the instrument panel.

[KFunk]

Just be sure you have a bracket that matches up. Why not just do the 320i alt like most people? I got mine for $40 brand new off-brand. Internal regulator, and only 3 wires. Tiny ground wire going to timing cover, big positive wire, and little D+ wire, which I presume goes to voltmeter to show actual voltage produced at alt.

[Chris_B]

Your ground needs to be as substantial as your alt output. D+ on BMW alternators only has to do with charging the field coils.

[KFunk]

then why does my car have a tiny little ground wire to the timing cover? I think others have mentioned the same wire. Since its such a short distance, guess there can't be much voltage drop. I might consider replacing it with something bigger tho for fun. Right now my charging system seems great though. We'll see how it goes once I start putting in my stereo.

By the way, here's my setup: