Try and find this eBay seller: "ace_alternators"
http://www.ebay.com/sch/ace_alternat...p2047675.l2562
I have not bought one of their upgrade alternators, but I've just bought a starter for my 1987 Turbo II.
These guys are one of the CHEAPEST on eBay.
My alternator came out to just $49.00 + $15.00 shipping, USPS Priority 3-day.
Other sellers were asking $70+!
I just installed it, and that thing zings!
These guys sell:
S4 alternators: 70A (stock?), 110A
S5 alternators: 80A (stock?), 110A, 140A
FD alternators: 100A (stock), 110A, 140A, 150A
(This is what is currently listed on their eBay items for sale listings.
I dunno if they offer an S4 / 140A...
These things are priced UNDER $200 EACH.
I'm going to buy one of these - probably FD / 150A - soon.
I currently run a stock FD rated at 100A.
I run a stock sized alternator pulley, so the system is not underdriven.
I'm telling you now, my car barely keeps up the voltage at night, idling, with headlights.
When my electric fan goes on, system voltage goes under 12.0VDC.
I haven't tested the actual current on the alternator, but it does have a problem dropping it's current field when I kill the engine in it's current configuration (i.e. field lead +12VDC all the time) - "S" or "R" terminal labeled in above diagram.
I have a circuit breaker inside the car, so I reset this to drop the active field on the alternator, or else there's parasitic current draw.
If I remember the #'s, it was about 1.0A before reset, and 0.3A after reset.
Let me go check the #'s tonight just to make sure...
I'm starting to put in a stereo system, so I want big amps.
Since I had a good experience with their starters, I'm willing to try their upgrade alternators...
If I had the BUCKS, I would go for a MechMan alternator for $549!
240A!!!
http://store.mechmanhighoutputaltern...rs/mazda/rx-7/
-Ted