Alternator upgrade

[Walter Moore]

Personally I consider scrap metal to be the only valid use for any externally regulated alternator. But to each his own.

When I installed the 100 amp single wire unit on my car, I left the factory fusable links in place, and installed the recommended #10 AWG wire directly from the alternator to the battery. (Which seems like a fuse to me, but that is what the alternator instructions called out.) This also has the benefit that it bypasses the amp meter, which makes me feel infinitely safer... but does require a volt meter to be able to monitor the charging operations.

However, I very intentionally built my own separately fused electrical box for my high power headlights, driving lights, fog lights, and electric fan. Since those were never intended to be part of the 40 amp main power circuit on my 37 year old car, I do not consider it reasonable to power them through the old wiring.

Anyone who intends to install a stereo with more than 200 watts would be well advised to upgrade the alternator, and install a separately fused circuit directly off of the alternator to power said unit. After all, the radio that came in the 240's was only a 6 watt unit.

The biggest problem that I have had with my alternator setup has been keeping it from eating belts. It took several attempts to get the pulleys lined up correctly. After that I found that the stock alternator belt isn't capable of carrying the load. Currently I have a general purpose V belt from Tractor supply installed. It works better than the stock belt, mostly because it is thicker and wider, but I don't know how long it will last.

In any event, if you upgrade the alternator, please consider separating out the high powered loads that require the higher power from your stock wiring. If you don't have any extra high powered loads, then why bother with the upgrade at all?

[sblake01]

Bo, my statement was more general rather than directed at anyone. After all, neither of you were the original poster and I was just giving my opinion. I don't know the condition of the wiring or what's been upgraded. Damn, I wish people wouldn't take things so personally here. I really don't care what anyone does to their car. It's their car.

[Arne]

Yes, there are reasons for the 140 amp upgrades, but very few of us really need them. Those few that do, generally know enough that they prepare properly for them. Your car sounds ready to handle it, Bo. But I didn't know that until now.

Worse, I have no clue what the condition of the wiring of the 240Z recently purchased by a 17 year-old newbie who might read this thread in 2011. All he sees is "more amps = better", which may not always be true.

I'd rather err on the side of caution. If you have beefed your car's wiring to the point that you know you're good for it, my replies weren't meant for you.

[richard1]

I know what it means to go through a major electrical problem on a complete original car that has never been modified in anyway and bought at 40K back in 2001.

In 2007,It has been bad luck and time consuming to fix the damage and a lot of money to find all the parts needed to put back the car on the street (months) in original condition.

Believe me, if you want your Z as original as possible, don't gamble on the alternator output.

Keep it in the range as recommended. I have a 60A and it fullfill all the requirements i have with A/C, stereo, lighting, fuel pump, fan and everything.

After all, they are classic cars and not intended as daily drivers anymore without serious potential problems that you may never know what is at the next corner.