where can I find a v belt pulley? I'm upgrading to a rx8 alternator in my s4
 

Like the title states, I already have rx8 alternator just need a pulley that will allow me to use this on my s4 turbo

Thanks

Mazdatrix, their FD v belt pully

Bore out the original pulley.

This. Go buy a unibit from Harbor Freight.

Thanks for the help guys

Getting closer to doing the swap, next obstacle is the connector, being I have a s4 I will need a electrical connector to plug into the rx8, I'm assuming from my search I need to get a pigtail from either a s5 fc or a FD as they are the same connectors, is there a easier way to getting this connector without getting a harness?

Ya there is.
Post a WTB in the 3rd Gen section.Or post that you need a Pigtail for an s5 in Sec gen parts.

That connector is common as dirt, lots of new(ish) Mazdas use it.
I'll bet a trip to a junkyard would reveal a suitable donor car in no time.

Try a MX6 alt connector?..

Good info thanks again for the help

I ran into a issue I haven't read about. The rx8 pulley had a spacer built on the pulley so it does not make contact with the cage. The s4 pulley does not, it has a separate spacer, do I transfer this spacer to the rx8 alternator? If so I'm assuming that needs to be enlarged to fit over the shaft as well?

Go to an alternator shop and ask for a bushing..17mm

I know of a local shop, I'll try that thanks

Long shot..but if you spot a Shot FD alt,then just tap the thing to get the middle bushing out.It sits on the front of the alt at the casing and shaft,.
You can see it clearly when the pulley is off the alternator.
I used one to clear my pulley from the case when I did a FD alt to FC engine application.

Update: I ended up taking the spacer for the s4 alternator and enlarged the opening to slip over the rx8 alternator shaft. It spins nice and free and appears to be properly spaced. I'll find out in a couple of weeks when it's mounted on the car. Easy fix.

I went one step further and painted the cage black being I'll be working on the engine bay appearance soon.

Attachment 646379

So is the rx8 altenator externally regulated?

https://www.rx7club.com/showthread.p...630&styleid=20

It is externally regulated. I have been researching trying to find the easiest external voltage regulator.

This is beginning to seem like more trouble than it's worth...external regulator?

But..But..it's painted..so nicely..

personally,for 50 bucks,I did this:
https://www.rx7club.com/2nd-gen-arch...r-swap-963821/

Yes, it is.

It's just that there are so many higher output, internally regulated options available- many of which can probably be painted- that I don't see the point to the extra work involved with this thing.

What does this unit bring to the table to justify the complication?

No money involved yet. The alternator is a !lifetime warranty reman, the only item that I will actually purchase is a external regulator. I wouldn't mind obtaining a FD alternator but not at close to $200. I'm running a stock tmic and from what I have read taurus alternator does not fit properly.

There are other options (other Mazdas use a similarly framed alt with higher outputs that are internally regulated...I'm using one from a 626) but I understand that an alternator in the hand is worth two in the bush, so I might be tempted as you are to continue with the RX8 unit.

The Taurus alternator fit my S4 TMIC when I had it. I may have gotten a slightly smaller belt, I don't remember. I posted about it in the big thread about Taurus alts.

FD alternator? I'm surprised any car would use an external regulator these days. Granted, it's been a looooong time since I've had to change one.