Holy Roller
Well-Known Member
If your running MSD ignition, what amp alternator would work? 60, 75 or 120 , it's a 383 in an a body. Thank you for your help
Ok, all my wiring is new and if 60 amps is enough. Would that be a round or squareback alternator, the car is a 68 barracuda and the 383 came out of a 66 charger. The wiring was upgraded from small block to bb wiring harnesses.It depends on your overall load. "What else" you have hooked up. An MSD by itself is not a spectacular "draw." Also if you have factory stock wiring and ammeter, that is NOT gonna put up with something much over 50A especially after 50 years of nonsense
Round or squareback?The MSD in and of itself isn't a huge draw but if your overall load (lights on, stereo blasting, etc.) and the load is more than your alternator can produce it would affect how well (or poor) the ignition system works.
You could get a JC Whitney winding that bumps the output of a stocker up about 50%.Either actually I believe, both came in 60A or in some cases higher. I do know that you can get a round back from Power Master (Summit) that provides 98A.
That said, if your wiring is original, pushing 90A or more might (read will) create more problems, potentially a fire.
Pretty much, I may be upgrading the radio later. And may upgrade the headlights also, but other than that..nothing but the MSDSo is the car completely stock other than the MSD? As to which alternator, I believe there is a 60A in either version but I am not sure.
What about the stock wiring?Think you'll need a 80 AMP alt like the 70's cars had with the electronic ignition, don't think the 60 will be enough, even going 100amp won't hurt anything but you'll have plenty of juice. Here's a calculator:
Calculate the Amperage You Need
Sounds like a great idea, thank you for the informationWell a 60A should get it done so long as the connections are good (like all of them especially the grounds). To that point, I would recommend you install some extra grounds, its the one thing Mopar did poorly (electrical system). I just finished completely rewiring my 73 Cuda, essentially building a custom wiring system and in doing so did tons of research on the subject as well as having 40+ years working on them. I can say with confidence that any vintage Mopar will benefit greatly from having good clean grounds and well as extra grounds installed (dash to firewall, engine to firewall and frame, etc). Time spent on this effort pays big dividends in the future.
Will do, thank you for the advice.There is a lot written on Mopar wiring and some dedicated websites, do some research yourself and you will be happy you did.
Great! Thank you for the linksSome good sites/information;
https://www.hemmings.com/magazine/hmn/2008/12/Chrysler-Alternators/1735462.html
MyMopar - Mopar Forums & Information - Mopar Wiring Diagrams 1966 to 1971
Vintage Chrysler electrical repairs and updates
Improved Wiring for older Mopars
The Early MoPar (60’s and 70’s) Wiring and How It Can Be Upgraded
Mopar Charging Systems
Mopar Charging System - MyMopar.com
Alt Text: 5 Things You Should Know Before Using a High-Output Alternator - OnAllCylinders
This should give you enough to make an informed decision.
Think you'll need a 80 AMP alt like the 70's cars had with the electronic ignition, don't think the 60 will be enough, even going 100amp won't hurt anything but you'll have plenty of juice. Here's a calculator:
Calculate the Amperage You Need
Pretty much your stock alternator.If your running MSD ignition, what amp alternator would work? 60, 75 or 120 , it's a 383 in an a body. Thank you for your help
Exactly.IIRC the MSD is an amp per 1K RPM. Did I read that somewhere? OOH, yes I did!
"...The amp draw is 1 amp per thousand RPM so at 4000 RPM, you should see a 4 amp draw at the battery." MSDtech
70's cars DID NOT come with 80A alternator unless they were the large frame optional 105A setup which was HUGE. Saying "won't hurt anything" is uninformed. There are MANY cases of the stock bulkhead connector and ammeter failing with LESS than 70a alternators.