I just bought an FD alternator to install on my FC, I've heard that you have to modify or change the mounting or something just a little bit to make it work. Can anyone tell me exactly what has to be done ?

 

its impossibe. there is no way it will work.

but seriously...search the forum before you start asking questions. odds are they have been covered 12313242 times just like the question youre asking now.

 

Yes, you can do this. I have one on my turbo. Silverrotor used to sell them and had instructions at one time. I have forgotten how I did it but a search will turn it up. This comes up a lot. Sorry I can't be of more help.

 

you need to swap pullies and find a spacer that fits. for fitment it fits the same way as the FC alternator bolts up but you will need a longer bolt with a nut for the adjuster.

 

https://www.rx7club.com/showthread.p...ernator+pulley

or


https://www.rx7club.com/showthread.p...ernator+pulley

or

http://www.geocities.com/rx7_ragtop/alternator.html


or


search for more if these don't suit you

 

FYI I was not able to make one fit on my S4 TII as it did not clear the intercooler. If you dont have a top mount, aside from the wiring difference it will bolt right in.

 

you can simply omit the arm off the back of the alternator and it will fit under the stock TMIC with a shorter belt.

 

thanks for the info, i appreciate it

 

You swap the B-post (the plastic arm the thick cable attches to) from your alternator onto the FD alternator. It then fits fine.

For S4's you need to do a wiring change as shown in these pics:

Alternator schematics: https://www.rx7club.com/attachment.p...hmentid=199213
Alternator pin-outs: https://www.rx7club.com/attachment.p...hmentid=170065

 

It doesn't get much better than those two liinks.

 

Thanks NZ! You just saved me having to search for those threads. I've got the alt and one of silverrotor's pullies, now I just gotta change out the wiring. And apparently I need a new adjuster bolt, which I didn't know about. Wish I knew about that before I made my last parts order...

 

Any nut and bolt of the right diameter will work.

I used an FD mounting/adjusting bracket. It needed quite a bit of modification to work, but it makes tightening the belts a lot easier.

 

note to self to find later.
good post NZ.

 

why not just buy an fc alt. ??
is there some kind of advantage to the fd alt. ??

 

FD alternators have a higher power rating.

 

^ Ya the FD alts are 100amps

 

if you dont have a buncha extra stuff an fc alt is adequate...but if you run a buncha power sucking stuff like amps for your stereo etc, then its nice to have the extra power.

 

S4 alts don't have a whole lot of room for extras which is why upgrading to a S5 or S6 is always good.