Sup people....I figured since my car was out of commission that I should do some things to it before I fix it. FYI- swapping the tranny because the Torque Converter went out, bee boo bee boo!

So I've been reading up on this swap and I couldnt really find any negatives to doing this and so I was wondering if anyone could tell me the negatives of doing this?

Hope to hear from ya'll- prodigy

87 GXL

 

None that I can think of.

 

The negative would be that anytime you do anything involving the electrical systems of an FC, you're asking for trouble.

Other than that you should be in good shape.

 

na, it should be fine. the negative is that the clip isn't a match so you've gotta rig something up your self to plug into the altornator.

Should be easy

 

the plug for your alternator will be the same as the fd as long as you have a s5

 

Go to the junkyard and get an alternator plug from a '90's Mazda. IIRC, I grabbed one from a 323 or 626 and it was a perfect fit.

 

I've been wanting to do this too. But what about the pulley?

 

^ I think that you have to bore the pulley out to make it fit.

 

higgi sells the pulleys,

 

Correct.
It's easily done, even on a fairly small lathe, so any machine shop could do it.

I've read of people here just grinding the bore out with a Dremel- apparently with success- but that makes the machinist in me cringe.

Alternatively, you could use the stock FD pulley and convert your waterpump and eshaft pulleys to the flat ribbed belt type. If you have no airpump, PS or AC I'd actually think this would be the ideal approach, giving the best drive to the waterpump with just the one belt.

Or you could buy the Higgi pulley and be done with it.

 

I emailed Higgi the other day, he no longer has pulleys and may not be making more.

GG

 

Even if you find the Higgi pulley (I have one) it doesn't fit the FD alt. without boring the center.

Unless he makes and adaptive-type that I'm not aware of.

 

is there a write up on this some where? i plan on doing this to my car because my alternator is junk.

 

[QUOTE=

Unless he makes and adaptive-type that I'm not aware of.[/QUOTE]


he once upon a time did, if we get enough people to get a pully he will make another run

check the group buy section

its going to be a pully for the fd alternator, but made to fit fc belts


lets get some people together

 

im down

 

i wouldnt rely on boring out the FC pulley... it will (in my mind) underdrive the alt. the FD pulley is much smaller for a reason. but i did bore an FC pulley for the hell of it anyways.

to hook up the alt you also need to run a wire from the alt to a 12v terminal thats always pushin 12v, otherwise the alt wll drain your batt while the car is off. theres TONS of info and diagrams on all the. just search a bit and you be fine.

 

Boring out the centre has zero effect on the pulley's speed. How could it?

 

i have a 100amp FD alt on my s5 turbo motor and they work fine, but as said u need to bore the center of the pully out i use a twin V style pully u will allso need a spacer behind the pully

 

Saw someone on ebay selling those pulleys new.

 

I just bought my pulley from rotaryinnovation.com (I think is the site) and I know a couple of others have purchased from there as well.

This comes pre-bored for the FD alternator, they look great, and the machining is quality.

I had to remove the shim from the FD alternator (not certain of exact term for it) and grind the server down slightly and the pulley fit great.

Full removal of old alt and install of new took < 45 minutes. Very, very happy with this product.

GG

 

ya u can play around at the parts store if their cool enough until you find a v-belt pulley with a big enough bore to fit the shaft on the fd alt. OR possibly swap out the rotors from the FC alt. into the FD alt. and as long as the rotor from the FC is spaced to far away from the stator windings then you will get all of 100 amp since its the stator windings that determine the ac ampereage that generated when spun at high rpm's. BUT have never done this on the rx7 just have done that kind of swapping on escorts and protege's.

 

it shouldn't under drive the alt, if you think about the basics behind it...

with a larger shaft the alternator would spin slower than with a small shaft
think about the gears on your old ten speed, you spin the pedals same speed, the smaller gear is harder but spins the tire faster, the large gear spins slower but much easier,
the FD alt has a larger shaft but it has a smaller drive pully so on an FD enging the alt gets spun just right... put a bigger pully on that same engine, you will underdrive the alt
put the fd alt on an fc, well you bored out the center and put a larger pully on, so, you are basically spinning the alt at the same speed
since both the shaft and the pully get bigger, its like shifter the rear gear up and shifting the front gear up

i may have done that whole thing in reverse there, been a while since i was on a ten speed, but hopefully you get my point...


also there is kind of a writeup in the 2nd gen archives, however its old and the pics no longer work... basically
you buy the alt, pully and pigtail (for s4, s5 plug fits), you need a spacer to line up pully and a longer bolt to mount the right side of alt (old style is threaded, s6 needs nut&bold) find the diagram for wiring to do that correctly...
remove you old one, wire up the new, bolt it down install shim & pully, ensure the pully lines up, install belt tighten to proper tension and start car...
its pretty basic to swap the alt, I have read you can put pretty much any alt in any car as long as the bolt holes line up, and you have some kind of knowledge of how to wire the think up...
if you search for FD ALTERNATOR in the 2nd gen section you will find a few threads on this including the diagrams you need...

good luck

 

Definitely NOT.
The shaft size is completely irrelevant.
It's the O.D. of the pulley that determines the drive ratio.
Since the pulley diameter is unchanged, so is the RPM of the alt shaft.

 

i belive it may make a small difference, thinking more into it i don't know really, would have to do some tests and calculations, i would say maybe a smaller shaft on the same alternator would just make the shaft itself spin faster not nesasarilly the internals or the pully just the shaft, so maybe the larger shaft is just for strength since its a larger alt, who knows, it works lol

and arn't we changing the pully OD when we go from FD to FC pully?

 

nope there is no negatives .....in swapping a fd alt into your fd i bought a dual v belt aluminum pulley with the rotor in the front from ebay....
hmm the only bad thing "i" have is that the belts sqeaks no matter much i try to adjust it ....it might be the pulley being new ???iono but this is the one i bought http://cgi.ebay.com/ebaymotors/RX-7-...spagenameZWDVW
not tyring to steal your thread but yea... any ideas guys/???