I miss my FB terribly. IT was a '81 GSL that had carb problems so I got rid of it.I now have a '89 GXL. More power and nicer. But still lacks the feel of my FB. Now I could easily get a working FC drivetrain. And get a decent FB for cheap. So here's what I was thinking of doing. Picking up a light base model with blown motor. pulling the 12A and dropping a 13B out of a S4. Running it alongside a GSL-SE tranny along with a GSL-SE rear end. Now my question is this. I know how to get the motor bolted in. I plan on running premix and just a header and intake for mods. Reason I'm not going GSL-SE is that they are heavier. Is it difficult to run the wiring harness and all the electronic bullshit that comes with a 13B? Or is it possible to strip the motor down to the basics (No OMP or emissions) and just worry about EGI and ignition?

 

If you are using the engine only, it shouldn't be very hard. The electrics aren't easy, but it's been done a few times, so it can't be that hard. You can always use the engine with a megasquirt unit for fuel and a dizzy for ignition. EU non-turbo models (S4) used a dizzy, with the same coils we know from our first gens, so it's possible.

 

Piece-O-cake,especially if smog isnt an issue.90% of the stock EGI wiring is contained in the right side harness.That harness is plug and play between the engine and ECU.The left side harness requires about 10 wires be run to power the ECU,coils,CAS and fuel pump.Not hard at all, with a factory manual.
If your going S4,might as well keep the OMP, since its manual not electric.S5 OMP and ECU requires a lot more work to convert into an FB(Ive done both)

The tough part of an FC conversion is fuel delivery.The return line needs to be enlarged with another stock feedline,the fuel pump needs to be an intank EFI or external EFI pump,and the tank must have a slosh/baffle box around the intank pickup/pump.Or run a fuel cell....

 

Yep, and if you do all that, you may as well just make it an S4 Turbo!! All the same work but much more power and upgrade capability.

 

True,it is just about the same work as doing a TII conversion.But now, after going through all the turbo teething issues for the last few years,I can see how a more reliable, revvy N/A conversion would be desirable.Especially a S5 setup.....

 

Just go with an SE, no conversions,less headache, no parts to look for and it's bullit proof. A little heavier, just ditch the electric windows, air conditioning, power steering and swap the leather for a pair of cloth buckets, pull all the sound deadening material out from under the carpet and you're there. A lot less work than looking for SE engine and supension parts for the conversion. Just bridgeport some 12a irons, get a weber side draft and you're fly'in.

 

i wanna do the same swap, could I use the SE gas tank and pump? What about the tank from the 86', would that fit?

 

86 up: no it won't fit at all. shaped differently due to IRS and spare wheel location.

GSL-SE: yes if you start with a 84-85 12A chassis, no if you have a 79-83 one.
You can use a 84-85 tank in a earlier car, but the spare wheel well needs to be modified. The spares on S3 cars (84-85) are the "limp home" types, to make space for the larger gastank.

 

steve84 gs tll how can I get in touch with you.
I have a few first gen 7's and i have one 90 S5 13b to put into one of them. the engine is stock with 90K miles on it. It came with harness... I also got a 351N ecu finally for a good price. I plan to put in RB full exhaust.
I could sure use some experience and insite from some one who has done this before and can recommend options for setup.

regards two79rx7's

 

Just curious --- when you say that you "miss the feel of your FB" what do you mean?

 

Hey 84stock, I'm lucky... my SE was one of the last ones made. It came with cloth buckets and no power steering (along with painted mirors) -- strange combo!

Anyhow, are you saying just add Webers and a turbo to the stock 13B and go? It seems that nobody bolts on a turbo to a RX-7. Most often it's a conversion project. I wonder how difficult the "bolt on" would be.

 

Just PM me.The S5 conversion was actually easier than the S4 because much of the wiring is simplfied on the S5 and there are less external sensors.

The trick is the front cover.To retain the stock ECU and OMP,the SE front cover has to be built up, then machined down and drilled/tapped to accept the larger electric S5 OMP.Other than that,theres no major hurdles with a S5 swap into a 1st gen.Just wiring and fuel delivery which is basically the same for a S4 or S5 swap......

 

What I mean by feel is the cars ability to react when I want it too. FC's handle better but lack that "feel". Reason why I said S4 is because I already have a perfectly good S4 motor already with harness and all. Second I like the look of the FB better than the FC. A '86 SE is still heavier and in my opinion uglier. I want a S4 N/A motor bolted to a GSL-SE tranny in a '81-83 GSL. I'm looking to have a 2000lb car with a modest 150hp. I want the motor to be emmision free with no air pump,power steering, and A.C. I understand the GSL-SE was significantly heavier than the previous FB's. (2200lbs vs. 2450lbs?) Also I would like the whole project to be somewhat cost effective.

 

if you use a S4 NA you can use the FC tranny aswell: direct fit. (just need to use the FB mounts, but they bolt on to the box)
it should be a rather straightforward install, only requiring a modified or custom engine brace, and a 12A or GLS-SE front cover. The wiring will be the most work. If you could use the ECU from a EU-spec S4, you can actually use the stock coils and dizzy. That'd be less wiring to do.

 

series 4 cars DO NOT use distributors nor the same coils as fb's

 

don't want to sound unfriendly, but could you PLEASE read my post again?
I said he could use a S4 ECU from a EUROPEAN FC. Those are fuel only and DO use the same distributor and coils as a FB. It would simplify installations greatly.

 

hmm. i wonder how difficult it would be to acquire an EU ECU... got one laying around, rotary emotions?

 

Well ****. I guess I'll bag the N/A idea. I was planning on putting a street ported S5 TII motor with a standalone system in my FC. Should I drop the turbo setup into the FC and put my S5 N/A setup into a FB? Or go turbo FB?

 

Yes.

 

depends. A turbo FB will be faster than a turbo FC (less wheight). A 13B NA FB will be faster than a 12A NA.
I went trubo FB and can't even get the damn thing to run: no ignition! (using Wolf 3D) Well, I have one spark firing, but it's only one trailing

 

Did you get someone to do this successfully? I talked to a couple machine shops. One didn't want to mess with a used part with an oil residue. The other wanted to make an adaptor plate. $300+6wks! I didn't think it would clear the water pump inlet. I ended up going with the SE OMP. I'm currently suplementing oil with pre-mix until I make a cable to operate the OMP...