rx7 alternator upgrade
 

do i use an FD alt i have alot of shit E-fan , door poper kit (keyless entrey) and my sterieo and shit

yes.
Attachment 700645
:D

ok found it so how much better is the fd alt

its 7.3 times better if your going over 25 mph but not under, and 17 times better if you have a NOS sticker on your car. There has been rumors that mutiple NOS stickers can double performance of your alt.

Depends, is the FD alternator in proper working condition.... if not, then it is worse

Off the top of my head, the s4 alt is 60 Amps, the s5 is 70, and the FD is 100. So the FD alt is a much better alt, but its not bolt-on. You have to change over the pullies and put in a spacer or something. If you have an s4 you have to switch over a plug as well. If you have an s4 you can also just upgrade to an s5 alt, but it also requires changing over the plug.

GM 1992 buick lesabre alt.

I think you're a bit skewed there. IIRC the S4 is 75, and the s5 is 80, while the FD is rated at 100, but some have been known to put out close to 130 amps!

The s3 is a 60 or 65 amp alternator, I believe.

I "upgraded" from my s4 alt to an s5. Very simple, just change over the plug... DO NOT fuck up the wiring though. Found it held voltage a little better with more loads on the motor compared to my s4, obviously due to the extra amps.

http://rx7.subbuteoclub.com/electrical.shtml
http://www.rx7.org/public/altxref.html
Click on picture here:
https://www.rx7club.com/showthread.p...42#post6156742

Also, a simple bump in idle, and cleaning all the power/ground contacts, or replacing/upgrading the 20 year old cables, will do plenty!

nice Natey

What's the output on those?

...yea...and what all is needed to convert it over to the gm alt?

Hmm, I maybe it was 70 amps for the s4 and 80 for the s5. I'm pretty sure there was a 10 amp diff, though.

A 13b is a 13b. All the alt's will fit. I have put fd's on fc's and fb's without any changes other than shaving the mounting bracket to clear the dizzy on a fb and the plug. I have a fd on my fb. All i did was change the pulley, make a harness about 6 inches long that plugs straight into my fb harness and into the fd alt, then bolted it straight on, no fab at all and it makes a hellified difference, especially if you have a lot of shit on your ride.

Any links to the swap?

the RX8 alternator is basically identical and also 100 amps, FYI. only have to get a v-pulley to match the shaft. reman is about $160, throw the FC alternator in for the core, like they can tell the difference.

use the fd alternator. it'll be enough for your needs. s4 is crap and s5 is a little upgrade but the fd one will give you much more power, especially at low rpms

You can use any alternator on any engine. Simple modification as long as you have the correct pulley and wiring diagram

Your English is shit. :blush:

If you currently do not have any issues, just leave it alone.

Mounting ear spacing and location are a factor as well, not so easily changed if the pulley isn't lining up properly.

BTW, several Mazdas use the same frame (body) as the FD/FC. I'm using one from a mid-90's 626 (IIRC) that tested at 110A output.
Has the same shaft diameter as the FD, so my already modified FC pulley fit right up.
Electrical connections were plug-n-play for a S5.

Mazdatrix sells a double sheath pulley for FD alternator on FC. Pulley is spaced out just like the oem FD alternator pulley, so the FD alternator is literally a direct swap, minus wiring of course.

FD Alt in FB.... 12a front cover and dual pulley:)

Ok, this really interests me. I would try to save on gas when I travel by not reving much on my RX-7. So I would only drive it to about 3000rpms. After awhile I notice that the battery would get weak. Hard starting and sometimes the battery would die out. So later I read that a RX-7 must be driven at a higher RPM to maintain the good running/operation of the car. So I would drive my car a little harder, 4500 rpms or higher. This actually seemed to help. The battery life stayed strong but I did loose on gas mileage. So does replacing the alternator (FC-S5) to a FD help so much that I won't have to drive my RX-7 at the higher RPMs? I would like to get back down to 3000 rpms and 300+ miles a tank. Does anybody know?

I have have gone through too many alternators on my t2 with aftermarket turbo etc.. they sound like a music box when turned by hand. can the stock alt. not handle 325+hp or not handle high revs? will the fd alternator upgrade handle the revs better without trashing the alt? I had a new s5 alt put on 6 months ago after dyno tuning, now it has failed also.

This sounds more like you have been over tightening your belts. That would cause your bearings to become a "music box" in any car. I cannot see how horse power by itself would affect alternator life.