Sean58

Ive been looking to buy a 89-92 13b turbo 2 engine , tranny, harness, ecu blah blah blah for my 84 gs just trying to get an idea of what I'm getting myself into.

I tried looking for threads and stuff about it but I can't find anything. Anyone have a link or something at least?

Richard Miller

Sean58

Lol alright thanks for your input. So I would probably just be better off to swap a 1st gen 13b and put a turbo kit on if then

diabolical1

iTrader: (3)

Here you go: 13B-T Swap archived thread.

Browse the Gen 1 Archives. There is a wealth of information. Among other things, there's a thread that addresses one option for wiring there as well.

vipernicus42

iTrader: (4)

At a bare minimum to get the engine to fit you're going to need to swap the oil pan and front cover for a GSL-SE oil pan and front cover. The FC's oil pan won't clear your steering rack and the FC front cover doesn't have the bolt holes to bolt the engine mount brace onto. Then you'll have to round-out the holes in the 12a brace a bit in order to make up the extra 20mm that you need since the engine is longer (or pick up a GSL-SE brace).

This assumes you are bolting the T2 engine to the 12a's tranny (which can totally be done from what I understand). If you're keeping the T2 tranny you'll need to fabricate mounts to mount it to the car, and probably get a custom driveshaft made. Not sure what else might get in your way - I don't know where the T2 tranny's shifter comes up for example, or if the starter wiring is any different. You might be able to swap the T2 tranny's guts into the 12a tranny's casing but that's a project in and of itself... it would save on mounting issues and a custom driveshaft though.

If your 12a is an 84 or 85 then you'll need to figure out an oil cooler setup somehow since those years had the stupid beehive water/oil cooler which won't work on your FC engine. Also you'll have to figure out rad hoses but that shouldn't be too hard.

The fuel pump will have to change since the 12a is low pressure (3.5psi give or take) and the EFI one is somewhere like ten times that. If your car isn't an 84-85 then your feed lines from your tank will probably not be large enough for the flow you want so you'll want to swap in a later tank or have the feed lines on yours redone by a shop. Any rubber hoses involved in the fuel system will also have to be changed, and you might want to run new hard fuel lines from back to front.

You'll need a different exhaust header since the pipes and bolts are 10mm further apart (half the 20mm difference in total engine length since the pipes and bolts are in the middle of each rotor housing). If you're lucky enough to be running an aftermarket system like RacingBeat you can just pick up their GSL-SE header and it should be good to bolt on and go.

Really the nightmare is going to be electrical. The 12a had absolutely no provisions for the FC's stock ECU and ignition. If you've got an aftermarket fuel/ignition controller you're likely better off than the stock ECU. I know virtually nothing about EFI setups so I'll leave the specifics to more knowledgeable folks.

It's not un-doable, it's just un-easy. But if you've already got a full FC turbo setup with all the bells and whistles you're almost halfway there and the difference in performance is going to be pretty damn noticeable.

Good luck,

Jon

vipernicus42

iTrader: (4)

Even with that idea I don't know if there are ready-made "turbo kits" for the GSL-SE's 13b, at least none that are available anymore. So you would be fabricating most of it yourself, and everything my post said about the exhaust and fuel would still have to be done since you're going from a carbureted car to a fuel-injected one.

The question you should probably ask at this point is "Why a turbo?". A well-built and ported 13b with an aftermarket carb is a much simpler swap and you get a lot of the power from it that you would for an FC's TII setup. It's worth thinking about staying naturally aspirated and carb'd for the simplicity, but if you want a little more power and better mileage you could switch to EFI without turbo - there's a cool thread up right now about someone installing a throttle body EFI system that looks really interesting.

What mods does the car have already? What exhaust are you running?

Myself I hope to eventually build a 13b with street-ported 4-port irons and high-comp rotors and see what it can do with a good carb and ported intake.

Cheers,

Jon

cpt_gloval

iTrader: (1)

You could do it with the stock ECM but you'd be pulling apart the loom and tracing wires for weeks. On both looms. There are handfuls of connections for the emissions gear you'll probably not have installed and only one handful of wires you'll actually need.

There are a lot of resources here. I did a GSL-SE 13b to FC 13b swap. Needed to use the FB front cover and oil pan to be able use the stock engine mounts and FB style water pump, if I remember it right. You will be having a custom prop shaft made, but that's probably one of the easier parts of it

If it were me, I'd invest the dollars in a stand alone EMS and dyno tune. Clear out all the stock engine harness and go from zero. But that's a can of worms on its own. But at least it'd be a can o worms was intimately familiar with, you know?

Sean58

Thanks everyone for your help.

vipernicus42

iTrader: (4)

Here's the link for the throttle body thread:
https://www.rx7club.com/1st-generati...h-12a-1124399/

Honestly if you've got a pretty stock car I'd start by upgrading the exhaust. You'll get somewhere around a 10-15% power bump just by swapping the exhaust and you'll need to have it done no matter what route you take. Most people here would agree that the "gold standard" for exhaust is Racing Beat (I've got one of their "Street-Port" systems myself) but it's not the only option. There are tons of folks who've built custom setups. Just be aware that rotaries have exhaust that's way hotter and louder than most piston engines so you'll melt through anything filled with fiberglass and you'll be throwing a lot of noise if you put something like a cherry bomb on the back of it.

Check out RB's exhaust here, but they last long enough that they're pretty common on the for-sale section here in good used shape:
Exhaust Complete Systems - Early Rotary & 1979-85 Mazda RX-7

Keep in mind that putting a 1st Gen 13b from a GSL-SE into the car is still going to be a heck of a project since you're going from carbureted to fuel-injected so you'll have all the fuel system and wiring headaches that the TII swap would, and you won't get near as much power out of it. I'd say that getting a 2nd Gen non-turbo 13b with an aftermarket carb setup is probably going to be the best bang for your buck in terms of power for the dollar (and the effort). Pick up a Series 4 or 5 N/A 13b, get an appropriate dellorto/holley/weber carb and intake setup for it, swap out the oil pan and front cover and you're 90% of the way there.

Depending on your time, budget and how much work you can do yourself you could rebuild and port that engine before swapping it in and gain even more power out of it. You'll save a lot of the headache and still have a fun car with some decent numbers to show for it. Plus you won't have to run hi-test for the turbo which, let's face it, gets pretty damn expensive.

Sean58

So helpful dude thank you! I'm a little confused on what years are carbureted and fuel injected. So a series 4/5 is 2nd gen carbureted???

cpt_gloval

iTrader: (1)

Series 1, 2 (78-83): only came carbureted, all models
Series 3 (85-85): GS, GSL were carbureted, GSL-SE was EFI
Series 4, 5 (86-91): only came EFI, turbo and non turbo
Series 6+ (92-93+): only came EFI, only came twin turbo

It's gonna be a lot easier to put a S4/S5 engine on a carburetor if you're putting it in a car that never had EFI, even though the engines were run EFI in the 2nd gens. Engine doesn't really care HOW the fuel gets atomized, as long as it is, and in the right quantities.

Sean58

So all 13b engines are fuel injected?? Its just a matter of replacing efi with a carb then is what you're saying, right? Fairly new with the rotary scene sorry for the noobie questions just trying to get a little more knowledge lol

cpt_gloval

iTrader: (1)

As far as RX-7s go, all 13B were EFI.

diabolical1

iTrader: (3)

I second this. In addition to the points Vipernicus42 made, the Gen 2 engines are (in my opinion) better than the S3 13Bs anyway. There are a better base to build on. The only value I see in the S3 engines is (1) if you have an SE that you want to keep fairly original, or (2) if you want to build an old-school 13B. I suppose if you got a S3, then you could put a newer rotating assembly, but that's a little beyond the scope of what you're talking about doing.

KansasCityREPU

iTrader: (9)

You could find or build a pre 1984 13B. They are four port and can be turbo'ed. You'll need to work out an after-market ECU (MS or other). Another option would be to use 12A irons and 1984/1985 13B housings.

Just a guess, but you're looking at $4k-$6k on the low end.

vipernicus42

iTrader: (4)

Exactly, yes! 2nd gen non-turbo engines were fuel injected but they work just fine with a carb on them! The turbo engines have low-compression rotors so they don't work carb'd unless you rebuild them with high compression rotors.

But you can get a 2nd gen (series 4 or 5) non turbo engine, drop it in with fairly little modification, put an aftermarket carb on it to replace the fuel injection, and end up with a reliable, powerful engine that will run regular gas all day.

vipernicus42

iTrader: (4)

Now, technically there were non-fuel-injected 13b engones but they were all in cars before the rx7 (like the rx4 and 5). Those engines are very rare and not good to build on. So for all intents and purposes "all" 13b engines were EFI and "all" 12a engines were carbureted (at least as far as the rx7 is concerned).

Can you switch a 12a to EFI or a 13b to carb? Yes to all. Just a matter of what your goals and budget are. If your car is built for a carb'd 12a then putting a carb on a 13b is a decent idea.

And if you're going to carb a 13b then the FC / 2nd Gen / Series 4,5 is the place to look.

Sean58

Time and money is not really an issue for me I just don't want too much of a headache doing a swap because I'll probably be doing most of this project by myself 😏. And the main goal is to have it boosted. So I'm pretty much weighing my options here. Thanks again for everyone's help I'd be so lost if I didn't join this forum.

diabolical1

iTrader: (3)

It's debatable, and totally up to you. Neither will be easy, and both carry their own learning curves. I happen to believe that you're better off going with fuel injection ... and more specifically, an aftermarket EMS.

Sean58

Alright cool. But all I see on racing beat is basically carbureted stuff unless I'm missing something? So where could I go get aftermarket parts for this thing. And where is a good website I could possibly have an engine shipped to me? I've looked on rx7 world they seem to be a pretty good place. But I wanna see if others have an opinion on that

cpt_gloval

iTrader: (1)

I find RX7 parts by keeping an eye on this forum's classified sections (the model-specific and regional ones), and having a search notification on Craigslist for a few nearby counties. I had to drive 120 miles round trip for my axle and 100 miles for the FC 13b I swapped into my GSL-SE.

diabolical1

iTrader: (3)

You're probably not going to build the car with RB parts, at least not many of them.
I'm going to use your words as the guideline here to construct an "as I see it"-scenario.

As I see it ... the engine itself is sort of an afterthought in the context of your build. What I mean is, you know what you want to build (a turbo 13B block) so finding one and having it built is just a detail - one that is relatively easy. As for sources, I would say try to find a block somewhat local to you, that way you can inspect it for yourself and KNOW what you're getting. If it's a runner, fine. If it's not, then that's fine, too - at least you'll have an idea what you need and there won't be any surprises. Another option is maybe one of those import houses - my brother has had a lot of luck buying engines from one fairly local to him (NY-NJ), but I have also heard horror stories from other people. You mentioned money NOT being an issue, maybe you'll want to buy a built engine from someone reputable, that can kill two birds with one stone. If you're keeping the OEM turbo, same thing. Having it refurbished is not really an issue - you may feel froggish and do it yourself. I've seen kits between $50 and $80. Obviously aftermarket turbos bring more work and more cost.

So the engine is not a huge issue. It's the other details that you will have to work out and will take up the most of your time.
- Your fuel system - will need to be built, but how? Will it be from scratch? Will you try to locate an SE tank and build around that? Will you get a Gen 2 and modify your stock tank, then build on that? The point is most everything will have to be designed by you - no pre-made "systems", just parts to put together. Sources? I got a lot of my stuff from Summit, but you may be able to do better.
- Your engine management - what can you afford? Where you will you get local support, and for what systems? Will you simply want to take the route of wiring up the OEM unit to work with your engine.
- Intercooler - do you weld and do metal work? If not, where will you get that done?
- Exhaust will be custom, but fairly easy to design and execute.
- Wiring - whether easy or hard, it's tedious!
- Oil - you'll need to address that because your car came with the beehive, and you'll need a radiator-type cooler plus plumbing for it. That's something that RB can supply (depending on which cooler you choose use).
- Miscellaneous - this is the category that probably causes the most pain. These are the things that you simply don't see coming. They love it when you "plan" stuff because ruining your plans are what they are all about.

Of course, the day comes when you get everything together. The car works beautifully, then you realize you have to drive it ... what happens when you need to turn or stop?

vipernicus42

iTrader: (4)

Diabolical's got a point. Do you weld?

If you've got a place to work on the car, a good set of tools and you can fabricate things (cutting, bending, welding) then you can put pretty much whatever the heck build you want in that car.

What I'm hearing is that you want a turbo because a turbo is cool and powerful and you don't care what it costs or how much effort it is. Great! I wish I had that leeway in choosing my project builds! So what I'd do if I were you is to head over to the 2nd Gen section and start looking at what they do for turbo builds. You don't want to bother with a carbureted turbo build - it works, Jeff20B can attest to that, but there are so many more options in fuel-injected turbo setups and you get much more granular control of the air/fuel mix. Figure out what aftermarket ECUs they use, which Turbos they upgrade to, what intercoolers they setup, and what upgrades to fuel and ignition they tend to do. Start putting together your list of components that you'll need to build up the system. There generally aren't "kits" so you're going to be fabricating a lot of little in-between bits to connect everything together.

There are plenty of folks who have built turbo builds, even here in the 1st Gen section (though not as many as in the 2nd and 3rd gen sections since they came with turbo options from the factory). Check what other people have done and dig in. It'll be a fun project, I'm sure.

Jon

vipernicus42

iTrader: (4)

In terms of places where you can get parts and engines the ones I can think of off the top of my head are Atkins Rotary, Mazdatrix and Racing Beat. But I don't deal with turbo and EFI much so I don't know where the good shops are for that kind of thing. For stock parts if you end up needing some RockAuto is decent, and if you download the parts fiche for your model you can get part numbers there to bring to Mazda or other parts stores sometimes. The pickings are slim nowadays since these cars are 35ish years old now, but sometimes you luck out.

Cpt Gloval has a good point with the Classifieds sections here, there's plenty of good stuff to be had there.

The 2nd gen guys probably have some good recommendations for shops too.

Jon

Sean58

Diabolical1, you hit the nail on the head with that. This is my 1st time ever doing an engine swap so that's pretty much why I have so many questions and I want it to go as smoothly as possible lol but I might be asking for too much 😂. Plus I figured this would be a cool project to do. But I guess I have to just stick with my guns and and go about it accordingly take it step by step and listen to the advice given. The thing that I'm scared of most is having a plan buying parts that I need and running into a road block or something because that's literally my luck. Another issue is idk where to get a wiring harness and an ecu from if I buy just an engine