Alternator Options?

[Pete_89T2]

Originally Posted by My5ABaby

FD alternator is probably the easiest. 100amp I believe?

That's correct - FD alternator is rated at 100A. For a swap into an S5, the wiring is plug & play. Wiring into an S4 requires some mods, and I've seen that discussed on the other forum.

What I don't know and would like to find out for myself is can you swap the FC alternator pulley over to an FD alternator without any machine shop work? FC's are v-belt, FDs have serpentine belt pulleys. I *think* the FD alt has a larger diameter shaft, which would mean the FC pulley would need to be bored out to fit.

[FerociousP]

Originally Posted by Pete_89T2

That's correct - FD alternator is rated at 100A. For a swap into an S5, the wiring is plug & play. Wiring into an S4 requires some mods, and I've seen that discussed on the other forum.

What I don't know and would like to find out for myself is can you swap the FC alternator pulley over to an FD alternator without any machine shop work? FC's are v-belt, FDs have serpentine belt pulleys. I *think* the FD alt has a larger diameter shaft, which would mean the FC pulley would need to be bored out to fit.

Most use a pulley designed for the FD alternator to be used in FC applications. It properly spaces belt grooves to align with the water pump and crank pulley.

I got mine from japan2la, a forum member on 7club that made pulleys specifically for this application, and even made them in many colors. I am not sure he is around any more. Occasionally they pop up used.

[hozzmanrx7]

Originally Posted by FerociousP

Most use a pulley designed for the FD alternator to be used in FC applications. It properly spaces belt grooves to align with the water pump and crank pulley.

I got mine from japan2la, a forum member on 7club that made pulleys specifically for this application, and even made them in many colors. I am not sure he is around any more. Occasionally they pop up used.

Brian/japan2la is still around and doing just fine. He unfortunately got himself in a pickle playing a middle man for some JSpec engines where his supplier basically f'd him royally and left him holding the bag. I personally bought two TII engines from Brian 5+ years ago that I dropped straight in and not a problem to date. Daily drive both of them. So from personal experience the infamous engine situation was an exception from the norm, but the 7club bull dog couldn't see past that.

I'm using his pulley on FD alternators I put in both those swaps. In one I didn't use any Loctite, the nut came loose, and the pulley got damaged. To make the offset correct, the full thread isn't available for the mounting nut as you can see in FerociousP's picture above. So Loctite is a must. But Brian replaced and shipped it for free despite my operator error.

Anyway, I'd bet he is the manufacturer for the ones Mazdatrix is selling as I've never seen as good a plug and play FD v-belt dual pulley from anyone else. He makes great stuff and is/was a great supplier of all things RX7 for years, but bad luck threw a wet blanket on that.

I'd spend the extra money and order his Titanium one via Mazdatrix. About double the price, but worth it IMO.

[RETed]

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