Will a FD alternator bolt up to a FC?
06-20-10, 12:47 AM
#2
Driving RX7's since 1979
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This link will give you all the answers you're looking for, or will.........
http://i30.photobucket.com/albums/c3...icah-gif-1.gif
Hint: That is one of the most common questions asked on this forum...........
http://i30.photobucket.com/albums/c3...icah-gif-1.gif
Hint: That is one of the most common questions asked on this forum...........
06-20-10, 03:08 AM
#4
FD alternators WILL fit. However there are a couple issues that will need addressed.
Firstly: You will have to remove the serpentine belt pulley from the FD unit and add a double sheave Vbelt pulley that will work with the FC (An fc double sheave will work if its redrilled to fit over the fd alt's shaft.)
Secondly: You need either an FD wiring harness pigtail, or a S5 FC's pigtail and rewire the alt. (I dont have the picture of it but im sure its been posted before).
And on second thought, why dont you just raid junkyards for a stock S4 alt? All the S4's alts are the same between models and years.
Firstly: You will have to remove the serpentine belt pulley from the FD unit and add a double sheave Vbelt pulley that will work with the FC (An fc double sheave will work if its redrilled to fit over the fd alt's shaft.)
Secondly: You need either an FD wiring harness pigtail, or a S5 FC's pigtail and rewire the alt. (I dont have the picture of it but im sure its been posted before).
And on second thought, why dont you just raid junkyards for a stock S4 alt? All the S4's alts are the same between models and years.
06-20-10, 05:51 AM
#6
No problem, although, if you NEED a stock alt to get you around till you can afford the 100+amp FD unit (ive got one on my car) I have a stock S4 alt that worked when it came out of a vert that supplied my newish motor/trans in my NA. Not going to use it as i've already rewired the harness to accept the FD unit, so if you want it I can zip it your way for 20ish + shipping?
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06-20-10, 01:16 PM
#8
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actually when it comes to searchin junk yards i found a stock s4 alt that was not froma rx7. its a common alt. i believe i hav e the same one on my justy if i remember right,
06-21-10, 11:24 AM
#9
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FD alternators WILL fit. However there are a couple issues that will need addressed.
Firstly: You will have to remove the serpentine belt pulley from the FD unit and add a double sheave Vbelt pulley that will work with the FC (An fc double sheave will work if its redrilled to fit over the fd alt's shaft.)
Secondly: You need either an FD wiring harness pigtail, or a S5 FC's pigtail and rewire the alt. (I dont have the picture of it but im sure its been posted before).
And on second thought, why dont you just raid junkyards for a stock S4 alt? All the S4's alts are the same between models and years.
Firstly: You will have to remove the serpentine belt pulley from the FD unit and add a double sheave Vbelt pulley that will work with the FC (An fc double sheave will work if its redrilled to fit over the fd alt's shaft.)
Secondly: You need either an FD wiring harness pigtail, or a S5 FC's pigtail and rewire the alt. (I dont have the picture of it but im sure its been posted before).
And on second thought, why dont you just raid junkyards for a stock S4 alt? All the S4's alts are the same between models and years.
Glad you enjoyed the link.
On that note, a search of the forum will provide a diagram for the rewiring using a S5 or FD alternator plug needed to do this in an S4. S5's are plug n play. Having done this myself to my S4 TurboVert, I can tell you it's well worth the effort. Everything works better now.
06-21-10, 12:07 PM
#10
The highlighted is the primary challenge in doing this swap. The ONLY fits right the first time pulley I've found anywhere (and I've tried a lot of different suppliers) is made by forum member Japan2LA. The tricky part is the proper size spacer between the pulley and the alternator itself.
Glad you enjoyed the link.
On that note, a search of the forum will provide a diagram for the rewiring using a S5 or FD alternator plug needed to do this in an S4. S5's are plug n play. Having done this myself to my S4 TurboVert, I can tell you it's well worth the effort. Everything works better now.
Glad you enjoyed the link.
On that note, a search of the forum will provide a diagram for the rewiring using a S5 or FD alternator plug needed to do this in an S4. S5's are plug n play. Having done this myself to my S4 TurboVert, I can tell you it's well worth the effort. Everything works better now.
Here is a link to my pulley.
I have a small quanity left in HKS purple or Cusco blue
Link: https://www.rx7club.com/2nd-generation-rx-7-1986-1992-parts-194/brand-new-dual-belt-pulley-fd3s-100amp-alternator-upgrade-860869/
06-21-10, 12:46 PM
#11
Also, something else you might consider is a Taurus Alternator. I'm running one and it laughs at everything I throw at it, including the almighty 2-speed Taurus E-fan. Before that, I was running a FD alt and it couldn't keep up with the fan, but did fine when using a stock clutch fan. Best of all, the FD Alt pulley for FCs is a perfect fit with zero modding.
With only a drill and hacksaw, you can make some short brackets so the taurus alt will bolt up. Make the holes 1/2" in diameter and 1 1/2" center to center. Slip a bolt through one of the brackets you just made and on the alternator. Do the same for the original alt mount and it'll line up very nicely. Put he other bracket on the back of the alt and original mount and you'll see a gap. That's where the spacer and five M10 washers come into play. Now remove the adjuster strap and flip it over so the curve goes out toward the driver's side and you'll see a gap between the alternator and adjuster, to be filled by four M10 washers.
Do note that if your belt had the old alt in the middle of the adjuster, it'll be at the bottom now and will take some effort to put on. What I found to work best is to bolt it up as directed above, but loose enough that you can move it freely in all directions. Now get the belt aligned in the front sheave on the passenger side and turn the whole engine over with a 17mm socket on the A/C pulley while pushing the belt towards the firewall. After a few cranks, it'll plop right in. Repeat to get it in the rear sheave so it'll align correctly and tighten everything down to spec.
Most of all, make sure the pulleys are aligned. If they're not lined up, it'll sound like this: http://www.youtube.com/watch?v=5PFIb-efzxs
With only a drill and hacksaw, you can make some short brackets so the taurus alt will bolt up. Make the holes 1/2" in diameter and 1 1/2" center to center. Slip a bolt through one of the brackets you just made and on the alternator. Do the same for the original alt mount and it'll line up very nicely. Put he other bracket on the back of the alt and original mount and you'll see a gap. That's where the spacer and five M10 washers come into play. Now remove the adjuster strap and flip it over so the curve goes out toward the driver's side and you'll see a gap between the alternator and adjuster, to be filled by four M10 washers.
Do note that if your belt had the old alt in the middle of the adjuster, it'll be at the bottom now and will take some effort to put on. What I found to work best is to bolt it up as directed above, but loose enough that you can move it freely in all directions. Now get the belt aligned in the front sheave on the passenger side and turn the whole engine over with a 17mm socket on the A/C pulley while pushing the belt towards the firewall. After a few cranks, it'll plop right in. Repeat to get it in the rear sheave so it'll align correctly and tighten everything down to spec.
Most of all, make sure the pulleys are aligned. If they're not lined up, it'll sound like this: http://www.youtube.com/watch?v=5PFIb-efzxs
