Which amp alternator would you run?

[BBQCYCLEWERKES]

Just finishing off buying my parts for my 427 SO build. I want to run a single wire built in regulator style alternator on the motor. What amp rating would you run? I was thinking an 80 or 100 amp. What are your thoughts. Thanks for the info.

[bobcowan]

Depends on what electrical items you'll be running. I have the standard items on my car: Lights, wipers, EFI, high powered ignition, fan. Nothing fancy, no stereo, no LED's. I use a standard '70 Mustang 65A alternater with no problems. Cheap, lifetime warrenty, easy to find a replacement.

The alternater will only produce as many amps as is needed. If you install a 200A unit, but only need 50A, that's what it will produce. Bigger units are expensive, heavy, and have more drag.

Look at all your electrical items. Add up the amp draw from each one, and see what your total draw would be if they were all running at the same time. Then add a small amount for a safety facter - theory and fact often do not corrospond.

[Zoom This]

bobcowan is correct. Most of the time you're going to be running headlights, dash lights,heater fan, electric fuel pump, at the most. Toss in an occasional brake light and/or turn signal and 65 amp single wire Powermaster alternator will do the job just fine!

[blykins]

Bob, shoot me an email...I've got a brand new Bosch/Motorcraft 100A one wire alternator here. I'll make you a great deal on it.

[vettestr]

The difference in purchase price between a 65 and a 100 amp is pretty small anymore and they are plentiful. The drag is relative to its charge rate so for me not a big issue.

A Cobra is all about overkill. Bigger is better. Go for the gusto. LOL

[philminotti]

If you plan on using the 'taurus fan' (you should, it kicks a), keep in mind that it can draw 30+ amps on high speed. I have EFI, msd spark box, fuel pump. Throw in headlights...it adds up. I bought a 100A unit from PA Performance. Excellent selection. IMHO, one wire doesn't get you much. There's two less wires, but remember that one wire alternators must exceed a specific rpm to begin charging. Not a big deal, but why add the extra complexity and opportunity for failure? JMO

[Bill Bess]

I agree..go with at least a 100 amp. I too have the Tauras fan, on high blow with the headlights on the alternater is working pretty hard to keep up. Go big.

[mreid]

Plus, if you go with the 100amp you will have enough excess to power a laser cannon upgrade in the future once you experience how crazy other drivers act when they see your cobra. Damn I wish I had one!