1jz rx-7 fc ms3x
 

Hey, this is a 1987 Mazda RX-7 that iv'e swapped a 1JZ/R154 into.

This swap was done on late nights fueled by lots of coffee, and no money because I was and still am a university student with a part-time job, trying to scrape by..so that's why this swap has taken me about 3 years.

Wired everything myself and fabricated what I could.

Straight out of Japan! Or Canada, probably Canada. It had Champion spark plugs. Anyway, it had 180 psi in each cylinder and no huge damage anywhere, so i was a happy camper.

https://cimg3.ibsrv.net/gimg/www.rx7...fe7027d15d.jpg

Used xcessive mounts in the front because it was before I bought my welder, and I fab'd up my cross-member because at the time xcessive did not have a crossmember that fit. Driftmotion extended my shifter housing (I think 2.5"? I don't remember.) I also used some polyurathane engine 240sx mounts i had kicking around that i cut down to size.

You don't have to cut out the front support, I did because It's a lot easier to mount the engine.


https://cimg3.ibsrv.net/gimg/www.rx7...6980b6122d.jpg

Anyway, once you mount it, you just have to throw the transmission slip yoke onto your driveshaft after you have it re-tubed for the right length. I only had to have mine re-tubed to be 1" longer.

Getting this engine to run is super easy. You just wire power to the ecu in 3 spots, and then ground the ecu at the right places and you're good to go. There are a bunch of pinouts that help.

This is what it sat like when I got it running on the OEM JZA70 ECU. Except it had all sorts of fucked things going on with it. Capacitors in the ECU were leaking, turbos were burning gobs of oil. I bought some used twins locally from someone with a 1JZ FC as well, and guess what, they were blown too. The IACV was stuck, bought another IACV, that ALSO got stuck. The coil packs were cracked all over the place, and it had a sticky lifter.

Lol needless to say, it was a shit show.

https://cimg8.ibsrv.net/gimg/www.rx7...da179fb57c.jpg

So a year later and once I saved up enough money, I decided to say screw it, and build a megasquirt. I got a megasquirt 3 with the expansion unit so it can support sequential fuel and sequential spark.

Built the thing in the last week of summer. All you need is a good soldering iron and lots of patience.

https://cimg9.ibsrv.net/gimg/www.rx7...9552fe1c1f.jpg

Once you build the mainboard, you bolt on the daughterboard (white), and the expansion card (green). Now all you do is load the firmware and that's pretty much it.

https://cimg3.ibsrv.net/gimg/www.rx7...f7c0ce04c3.jpg

Testing phase. Trying to familiarize myself with the ecu and tunerstudio. I also built a few testers for it (Jim-stim, and the stim-X or whatever its called). You don't need to build them, but they give you some confidence that you aren't screwing anything up.

https://cimg1.ibsrv.net/gimg/www.rx7...7c933c3011.jpg

Since im using knock off 2-wire COP's i found on ebay before I knew that I was gonna get megasquirted, I had to build an external igniter for them. It's just 6 BIP373 transistors wired between the ecu pin and coil pack end. This is how you make a homemade igniter for $40.

https://cimg0.ibsrv.net/gimg/www.rx7...e2ae891a17.jpg

This is the completed ECU and custom wiring harness that I made.

It was a whole lot easier making a brand new harness from scratch, rather than trying to figure out what the hell Toyota did.


https://cimg8.ibsrv.net/gimg/www.rx7...af9633ec5f.jpg


Since my turbos were blown, I decided to get a CX Racing turbo kit. I also have a cxracing radiator and intercooler. Yeah this stuff works fine; I guess we'll see how the turbo holds up, but it was like $200 so whatever. So far it boosts well.

Also we powder coated my valve covers and intake plenum with my buddy's harbor freight powder coating gun and old conventional oven.


https://cimg3.ibsrv.net/gimg/www.rx7...b50f1f1ee1.jpg


https://cimg3.ibsrv.net/gimg/www.rx7...44e6a969c6.jpg

I found a good spark map online, and I tuned the fuel myself. Only running 12 psi of boost for now, and I haven't yet turned it up because this is the fastest car iv'e driven and I'm still getting used to it.

Im using a GT35 size turbo & 550cc injectors.

https://cimg3.ibsrv.net/gimg/www.rx7...8dbc4e18b5.jpg

Unfortunately, hood fitment is not ideal because I decided to not use subframe spacers, but that's fine. A hood vent works to cover that huge hole up.


https://cimg1.ibsrv.net/gimg/www.rx7...b7d176cae1.jpg

For my dash setup, i'm just running my tablet with Shadow Dash MS App. It's amazing. Pretty much all I need. I only decided to use the gauges because I had them from before.

https://cimg8.ibsrv.net/gimg/www.rx7...637063e3ff.jpg


https://cimg9.ibsrv.net/gimg/www.rx7...7964cc2556.jpg

I'll have to take a video of some pulls and post it up.

Anyway. It's been a long process, but it's done. It's janky in some ways, but it's extremely fun to drive and really, really fast. Im glad I decided to throw the old dorito can out and go this route.

If anyone is interested in my tune, let me know and ill post up the engine settings as well as the tables. I still need to rent a dyno, but for now road tuning as got me pretty far.

Future plans: Arduino Keycode entry start. I now have the time to start writing the code for it. I'm no programmer so this will surely take awhile.


https://cimg9.ibsrv.net/gimg/www.rx7...7629c74029.jpg


Thanks for reading! Let me know if you have any questions.

And this is what I do in my spare time with my collegues on the WWU FSAE team.


https://cimg5.ibsrv.net/gimg/www.rx7...2f6eb94858.png

love the key pad idea. Good luck. I just started playing with audrino stuff. I am a long way from being that creative

awesome build! good to see another arduino user on here!:)

how did you get that tablet to work, i assume you cant do that with a stock 1jz ecu? neat idea but im not on your wiring level at all.

The reason I am able to run a tablet is because of the megasquirt. It connects to my ECU through bluetooth, and I can display all of my engine functions on it.

You can also create sweet ass dashboards on it; its pretty cool. Its a $10 app. Doesn't have latency issues either, and it can datalog.

Finally started getting out at the track. 3rd event, and im finally starting to get it down.

Dyno'd it for an hour and made 320 WHP at the end of it! I'll probably turn up my boost; I guess it's time to blow up my ebay turbo lol.

https://youtu.be/9IlTY2Jaluc

This might be stupid but I think I heard that some jz's are drive by wire. Was yours just throttle cable or wire? Also could you explain how you ran the cable or drive by wire, either or. Its the one thing I haven't thought about. I'll be purchasing my swap soon but I'm more focused on getting an r154 that has the OEM longer shift linkage paired with my engine and no hydro fan BS, not so much on drive by wire or not.

Mine came drive-by-cable. I mig-welded the steel wire that came on my engine to the butt-end of the rx7 throttle cable. Although i did this, I do not recommend this! It will fatigue and eventually fail on me one of these days; im pushing a year and 4 drift events on this janky ass cable and it hasn't failed on me yet. But it will, probably.

You could probably have a bike shop make you a cable, but they might not have the ends you need.

I guess you could also cut the ends off of the current cables, and drill them to thread the wire through and tie it. idk. Or machine ends out of aluminum, if you have the means.

I don't have any experience with drive-by-wire, but i hear it's very nice.

I imagine you will have to manufacture a way to make your gas pedal spring back, and use a linear potentiometer to read how much your pedal is being moved, which would then tell the ecu how much it needs to open the butterfly. Depending on your ECU, you might be able to just have it interpret that variable resistance to adjust input voltage to the tps, or use an Arduino to interpret the data. I'm sorry that I took such a DIY approach to it.

They might make pedal box kits too.

Oh, I'll be you'll pick it up easily. It's a simplified version of C++ so if you have any programming experience, you can get used to the syntax and the language is well documented.

Use your Unos to prototype, then transfer the code to an ATTINY or a Nano/Mini for a more permanent package that can be directly soldered to a PC board and conformal coated.

I'm doing something very similar to my Cosmo. Using Arduinos to build a body control module which among other things, integrates the various ways of opening the doors. I have shaved doors and solenoids, so all that needs a bit of logic to control the solenoid based on the unlock button in the car, disable the solenoids if the vehicle is moving, the unlock method from outside, provide an output to let the illumination Arduino know to deal with the interior lighting, etc.

Once you've entered the world of programmable microcontrollers, everything changes. :)

Oh and Microsoft gives Visual Studio 2015 away for free. There is an add-in called Visual Micro which enables it to work with Arduino. Way better than the stock Arduino software with far more robust debugging.

That's very cool that you're going to actuate your doors through a microcontroller. Will you be using a some sort of low-range wifi or fios shield to actuate these solenoids from a remote switch?

Actually, most recently iv'e made a circuit paired with an arduino mini pro to actuate a 12V DC motor that moves Yamaha R6 Velocity stacks. At a certain RPM, they lift and simulate short runner length, which changes the pulse-waves in the intake allowing air to be pulled into the head quicker. It's a simple project I just finished for a customer. I should post a video up soon.

You're absolutely right though; it's a total game-changer once you start getting into electronics and programming.

There will be three methods of solenoid activation. Pressing the button inside the car (near the front of the arm wrest). This button will be disabled via an output from the MS3-Pro when the vehicle is moving faster than say, 5MPH/8KPH. The 2nd is a standard wireless remote, this one made by AutoLoc for shaved door kits. Nothing special here, it just activates an output for 1 second when the button is pressed. The third method is...well, I'm keeping that one secret until it is implemented and presented in video. :) Sorry. Don't want to give away the plot.

That is awesome! I'd love to see the video and the development!

Hey!

Haven't posted in awhile, but this is a Raspberry Pi dashboard I have developed for the FC.

Essentially, it's just Linux that iv'e commanded to auto-boot Tunerstudio on.

In other news, i've almost finished manufacturing my "trailing spindles" for the FC, but more on that later.

The video of the boot-up is below.

The new corner packages are probably about a week out; I have just finished the knuckles themselves, but I still need to modify the coil over lower strut for different KPI, and manufacture a new strut tower mount for the coilover.

In the meantime, I 3D printed a glove box latch hook; I lost mine awhile ago when I moved and didn't want to buy an entire glove box.

https://cimg6.ibsrv.net/gimg/www.rx7...2efe069f11.jpg