There is a new alternator in the latest Mid-America catalog I just got. It's a black, powder-coated unit with a significant increase in amperage over the stock job (1972 with a/c,power windows). Now, I'm no electrical system wizard, but is 32 year old wiring able to handle 85 to 100 amps without something else going haywire (sorry)? Is this an improvement over the "General's" original design (61 amps), and could there be an enhancement in performance due to that increase? My alternator's due for renewal and I'm a little leery about making this choice. What would you guys do?


JR

Just replaced mine a couple months ago. Went with the matching AC Delco version including original current specs. I don't have any additional significant electrical loads added from the stock configuration, so I figured since it was good for 25 years it must have been specified pretty close to what is needed. Unless you have added some auxiliary equipment requiring the additional current, I'm not sure that you will be gaining anything by going up in current.

Going to a larger capacity alt. should not be any problem. Having more current available does not mean you are supplying more current to the load. If your stereo needs 10amps it will take 10amps. Just increasing the available current will not make it draw more. Your AC, ignition, wipers, lights, etc. will still draw the same as always. Increasing the alternator current capacity will help recharge your battery faster and let you add that 600 watt stereo amp and speakers with out killing your battery so quickly!

Owen -

All of that (what you said) makes perfect sense. So why then is there an option for a higher output version?

I was looking at this as well - there's a chrome one that comes at the higher level. What's the need/benefit?

Thanks to all for your input on OUTPUT (that's bad!). Something I forgot to mention is the original distributor has been replaced with an HEI unit. I guess it goes back to the original question, will this system benefit from the increased amperage. Bear with me, Guys, when it comes to this stuff, I'm a rookie.

JR

Eric76 said: Owen - All of that (what you said) makes perfect sense. So why then is there an option for a higher output version? I was looking at this as well - there's a chrome one that comes at the higher level. What's the need/benefit?

There's only benefit if you have the need. The electrical demands of a stock C3 are relatively minimal - mainly because the only (electrical) options were slightly better radios and power windows and door locks.

But when you start to modify (and especially if one goes over-the-top) the more electrical gadgets and gizmos you add to a vehicle, the greater the demand. Turning one's car into a twenty-gaziliion-watt rolling concert hall; adding heated or powered seats; electrically-adjustable suspension systems; motorized door openers. This kind of stuff eats up the juice. (Although, where you could FIT all this on a small frame car like a Vette is a little beyond my imagination.)

If your car is basically stock, there is no real need for a high-output alternator. So, there is no practical benefit to installing one. Typically, cars with power options are factory-equipped with higher amperage batteries in order to store some "extra" juice for the power systems. There is actually a US federal standard that requires this "emergency supply" of elctricity for power windows.

Hope this helps.

John

|UPDATED|5/1/2004 4:31:39 AM (AZT)|/UPDATED|

As long as you replace the alternator with one that has an internal voltage regulator, you should be OK, as the regulator is matched to the alternator's output capabilities. Problems may occur with older cars that have an external regulator that isn't matched to the capabilities of a higher output alternator. I'm not sure when GM changed to the internal regulator, but I believe it covers most if not all of the C3 years.

Gunslinger said: . . . I'm not sure when GM changed to the internal regulator, but I believe it covers most if not all of the C3 years . . .

1963

John

|UPDATED|5/1/2004 4:44:00 AM (AZT)|/UPDATED|

JR;

Alternators are rated for their max output capability. higher output means the rotor coils and the stator coils have been beefed up, and the output diodes have higher power ratings. Generally speaking, for a given design, the output rating of an alternator is a function of RPM and temperature.

As the alternator in my 72 has died a quiet death, I'm looking at the upgrade options at SummitRacing.com. I'm planning on adding some aux lights and electric fans, so I'll be needing some additional output capability.

No worries though, the internal voltage regulator will only allow the alternator to output what your vehicle requires. As long as the wiring is OK for the stock rated alt., you should have no problems.

NJ BB Ken

The only other advantage of a stronger alternator come with driving styles. If you drive a lot of short trips at night with acessories on, the highter output will help.
During short trip with a heavy amp load, the alt may not have time to charge the battery, where a higher output would shorten that time by a small amount.

But I'm talking less than a couple miles, with everything in the car on. Not how most of us drive anything, let alone our C3s. IT CRUISING TIME!!