I am in the beginning stages of swapping a rotary into a FWD '87 Celica GTS. Yes,first of all,I DO realize how much work it is going to be.

Anyways,since I am dropping the 3SGE that is in it and going rotary,I was thinking about putting a carburated 12A into it with an 88-89 Celica Alltrac driveshaft (or custom driveshaft) and using the Alltrac's differential and rear suspension. Using the Alltrac's rear end parts would save me lots of cutting.

1. Is it true a 12A can be ported bigger before you hit the water jackets than a 13b?

2. If I put in a carbed 12A,since I plan to still be using existing wiring from the Celica for things like the wipers,power mirrors,lights,power seats etc,should I keep my wiring harness and somehow use the 12A and the carb to power the car and the fuel pump,and then somehow have the Celica's wiring hooked up to power the accessories,or something like that. Maybe somebody has a better idea,I am not the wisest when it comes to electrical compnents.

3. If I go 13B FI and use the ECU and harness,would it be possible to splice the Toyota's wiring into the harness to make the accessories and such work in harmony with the Mazda's componentry?

That's about all,I beleive I have the rest under control.

Wish me luck,lol.

 

How good are you with electronics? Good at reading diagrams?

I'd ditch all the ECU related wiring from the Toyota and leave all the accessory wire intact... Save weight...

Use the RX-7 fuel pump and realted parts.

If you use EFI on the rotary, make your own independant wiring harness for the ECU...

But then again, I'm meticulous like that.

If I had the time, I'd get the diagrams and tell you which wires to cut.

 

Definitely easiest to use a carb. Their is an excellent wiring diagram that I found about how to wire a carbed motor up. I did this job today in rotary powered Triumph, and it was way easy. I used some of the original engine wiring harness connected to a foglight relay. Also wired up the alternator. Took me an hour to completely wire up the rotary with all original clips and hook ups, and that including the starter! EFI would not be as fast. It can be done for sure, but I would leave evrything toyota intact and wire up the engine separately. These are the kindof things that make an engine swap take a year. Its not the engine mounting, its the electrical junk. Took me 2 days to mount my rotary, going on 6 days for all the other ****. Good luck.

 

That's awesome man.

I can't answer any of your questions but I'll wish you luck and tell you that I want to hear how it comes out :-)

 

Well Xavier and Pele,that is exactly what I wanted to hear! Thank you so much,you've just helped a great deal. I have very little experience with wiring and wiring diagrams,but I have friends that are very good with that stuff,so they would be able to help me out.

Basically my goal is to have complete RX7 mechanicals all stuffed under a Celica body.

Xavier,I will probably do what you said to do with the wiring. As I have been taking my Celica apart,I have been trying to keep all the wiring intact.

Do I only need to use my Celica's wiring harness,and then seperately hook it up with the rotary? I don't need my Celica's ecu do I?

Anyways,thanks so much for the guidance!

 

Celica engine and ECU go together...

If you leave the Celica wiring intact you will have the following penalties:

More dead weight
More complications in finding trouble
The probability of shorts and such increases

However you also get the folliwing pros:

You can go back to Celica mechanicals if you like
Less work, you don't have to gut the harnesses
You can use the wiring for another purpose. That is all up to you.


I only suggested removing the wiring because I don't like it when there's wires that end up nowhere... You're probably only going to be removing the engine to ECU harness anyhow, as anything after the firewall is for accessories.

The only trouble I forsee is connecting the Celica tach to the Rotary ignition system and finding a fuel pump that'll fit into the Celica tank and put out low PSI for the carb.

Take pics plz.

 

Thats easy, just use the celica pump, and plumb in a fuel pressure regulator to drop the pressure to your desired PSI.

 

He can use the celica fuel pump as long as he uses a return style pressure regulator. He can turn the fuel pressure down to 3psi if he wants.

 

About the gas tank issue,I was thinking about using the RX7's fuel tank,but mount it either in the trunk or where the back seats used to go. I may have to do this incase I end up using an RX7 rear end rather than an Alltrac.

As for the wiring,I only want the Celica's wiring to power the following things:

headlights,turn signals,wipers,instrument panel lights,power mirrors,power lumbar support,and climate controls.

This isn't going to be some cushy daily driver car,it's going to be an all out insane race prepped but street legal car,so I can live with many compromises.

I was also thinking about using the RX7's insrument panel,otherwise,I will keep the Celica's gauges and hook up one of those ricer tachs. As I progess into the project,I will find out how things go. Right now I am only at the stage of pulling the original motor.

 

power mirrors and power lumbar support...too funny.

sit on a milk crate, it's good for the soul.

 

tach hook up is simple, a rotary exhibits the same amount of ignition pulses as a 4-cylinder. The ecu should not be needed unless it controls other stuff, but ~I doubt it does. I checked spark, etc, today and everything works PERFECTLY. Also wired up the tach and watched it move. Only problem with tach is that it may not be accurate at high RPM since it was not designed to have to display high RPMs. The tach may show 8 or 9 thousand on the guage, but that is certainly not an indication that it will actually display there.
I think leaving the wiring allows huge time savings. The only RX-7 wiring used in my spitfire is the main power wire going to the coil and the ignitors, the clip for the alternator, and the insulated starter solenoid wire. Pulling a harness will save weight, but it takes a LONG time. Leave it till you get the car running, and then if the engine doesn't work, you won't be stuck. Lots of advice, take what you will from it. Good luck.
Ohhh, I see NO reason to switch to the RX-7 tank. Will only take time and gives you no benefits. It could drastically increase the time to finish the project. You do want to drive it some day, don't ya?

 

I'd use the All-Trac rear end as it's less fab work...

Use the Celica fuel tank and sender so it'll work with the stock Gauge...

Speedo might be a bit troublesome if it's like my Civic... (Electronic speedo wiht Vechicle speed sensor on the tranny.) If it's cable actuated it might be a bit easier to connect to the RX-7 tranny.

Temp gauge won't be too hard... See if you can put the Celica temp sensor in the RX-7 engine...

Ditto on the oil pressure sensor.

Volt gauge runs off the 12V positive... No problem...

On 2nd thought, the Celica tach shouldnt be hard, unless it runs off the Celica ECU...

EDIT: Know what... I jeat read that it's an '87 Celica... The Tach and speedo should be no problem.

 

the tach on the celica redlines at 6700,speedo reads up to 150mph (240kmh). the speedo is cable driven,but it's hooked up to the front wheels,so I'll have to hook it up to the rear.

Even by using a Celica rear end,I think I may still have to modify my floor pan a little to get the driveshaft to fit. Ditto with the firewall. it is going to have to be mangled to get the RX7 tranny in. I will keep the Celica fuel tank in it's current spot and just use an RX7 sending unit I guess.

I beleive I found my ECU today as I was pulling the dash,and it sits right behind the firewall,on the tunnel behind where the stereo sat.

 

Go carb bud alot easier, if you go F.I gonna end up in a lot of crap unless you transfer the whole electrical from the rx7 you go carb dont need the electrical only ignition and what ever is on the engine, i would also take off rats nest (emission) to make it alot more easier and the only thing you have to worry about now if fabrication

 

Use the Celica sending unit because it matches the Celica fuel gauge.

You can get the gauge faces reprinted, or just ignore the redline. That's what I do in the Civic...

For the speedo, use the All-Trac rear end with the stock gear ratio. Find a longer speedo cable that'll go from the gauge cluster to the speedo port on the RX-7 tranny... You'll need to change speedo drivegears to calibrate.

 

^ taking note. Will do that.

Now what about registering this car? VIN reads an 87 Toyota,but will be powered by an 84 12A. Because a car has to be 20 years old to be exempt from emissions here,would I be able to get exempted from the emissions test because it is powered by a 20 year old engine,but in a 17 yr old car? Wonder how that would work.

 

You're probably gonna need to check with your department of motor vehicles or whatever. Might need to register it as a custom vehicle...

If you add cats though and keep emissions systems intact for the msot part, you should be fine for emissions.

 

I don't know about there, but around here you can't put an older motor in a newer car and still be legal.

 

If the vehicle has an engine that was not available from the factory, it will have to pass 1980 emissions standards.

Keep your air pump and connect it directly to the cat for your e-test.

As for wiring, hunt down ALL of the wiring diagrams for the chassis and for the engine. 12v is 12v, so you just need to power things properly, and it should all work. If you can use the celica senders in the 12a, you can keep the celica dash, otherwise it will be A LOT of extra wiring.

Also, removing the rats nest will allow you to significantly clean up the wiring necessary to run the engine.

The most usefull tool you can have, after the diagrams and a good multimeter, is an electrical harness pin tool.

I don't know where you can get one (Borrowed mine from a previous job), but they are hella handy.

Let me know if you need help with this, I just went through pretty much the same thing Fuel Injecting my GSL.

 

A Celica sender should thread into the Mazda engine. Like for oil pressure and engine temp. It's all just metric pipe thread or whatever.

Fuel level is already covered. And volt gauge should be straight forward.

I think it's just a matter of hooking wires to wires, which is simple when you have enough diagrams, or patience and a multimeter.

The hardest part of this will be the mounting of the engine.