[T3] Alternators for T-3's...

Brent Bottolfson brent at bottolfson.net
Fri Apr 27 20:37:53 PDT 2012

On 4/27/12 6:32 PM, Keith Park wrote:
> I just never found the alternator I had to be any more stable than the
> Generator, it wouldn't charge at idle and its regulator worked about as well
> as the T3 one in maintaining system voltage above an idle, I think its
> entirely up to the regulator above an idle as to weather the voltage is
> steady or not.
> Its possible on these kits that they have sized the pulley small enough that
> they charge at idle, but then they may be overspeeding at highway speeds...
> I just don't know but a stock T4 alternator with a stock pulley does NOT
> charge at idle (and I was surprised when I first found this out!)

The alternators we're using come with a pulley that puts the ratio right 
at 3:1.  Someone PM'd me on theSamba about it and I measured it all, but 
it was a few months ago and that message is now gone.  It's the exact 
same one that is in the advertised kit.  They rated for 50 amps max and 
18,000 rpm max.

Anything over 800 rpm the alternator will charge, as the charge setting 
is 2400 rpm for the alternator.  I verified on my setup and was getting 
somewhere around 14.5 volts at the battery at 850 rpm.  It was awhile 
ago, but I posted the actual values in the 'conversion' thread.

I don't know if that's ok voltage for a stock EFI.  ???

The alternators are commonly sold as mini 1-wire alternators.  But, I 
like my idiot light to work.  For this, I had to swap the VR on the 
alternator.  It's very easy, only a few screws, and the regulators are 
easy to find.

If the brackets work out, I'll make up a how to for the alternator.  I 
don't think it's worth putting together a kit with the alternator 
included as you'd be paying for shipping twice.

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