Reference to Jeffbucc's build thread. This post, specifically: https://www.miataturbo.net/build-thr...5/#post1103205

 

OMG. That is the most insane and awesome thing I've seen in a long time. What a dude.

 

Oh, but of course, I could never forget. I re-visited that thread again recently and it's just as OCD as I remembered it. I'll take that as a huge compliment.

 

Long lapse of progress here, but things are moving along again. Since my last update here I

• Broke my back snowboarding (fortunately relatively minor all things considered, t5 compression fracture).
• Upgraded I/C and ducting on the miata.
• Installed a splitter on the miata.
• Blew up my miata's 5 speed at FM open house.
• Bought another miata, stole the 6 speed + 3.6 from it, and fixed my turbo car.
• Installed a new turbo and re-tuned the turbo miata.
• Chased and fixed an issue with my o2 sensor controller on that car, which took a lot of time/troubleshooting.
• Fixed the parts car I stole the 6 speed with, by swapping in a 5 speed + 1.6 diff. Sold that to my co worker.
• Tracked my NB a few times.

Excuses, I know. But I've made some good progress on the car the last few months. I've put in so many hours getting the turbo setup refreshed and the engine dressed, but it feels like there's not a whole lot to show for that. But that's OK, it's coming out pretty nice and I'm psyched.

Fuel pump in, for good, with the fuel pump rewire. This fixes voltage dropping under load on the FD platform, which is known to fuel starve 'em at high RPM.



Dove into my non-sequential conversion. This really simplifies the turbo setup and makes the sequentials run as a single. And supposedly porting them like this will free up a few HP, making them at least 315+whp capable (maybe more?). These are 60k km JDM turbos I picked up on a work trip last year and shipped home. The turbos are clean but the manifold was buggered so I had to swap the manifold (piece that joins the two turbos together) from the turbos that came with my car. This was a PITA due to 4 completely seized studs that broke off and needed delicate extraction. Lots of hours on that stupid manifold drilling out the studs, re-tapping, etc. It came out great - though no real pics of that process (it sucked). In this pic you can see the old "buggered" manifold that someone welded a stud back on. I ditched that for the clean manifold you see in the later pics.



Before any porting. I didn't go crazy, just opened up anywhere that it necked down. For instance right on the inlet of the manifolds:




You'll see that I like to use the "glass and sandpaper" method of planing surfaces flat. This has never done me wrong, I've even done some subaru heads this way and they've held up for 100k+ miles! My turbo hardware on the miata is done the same way.





And this is the good "manifold" housing I got studs extracted from, planed flat, and used for the turbo setup. I can't emphasize enough how many hours I spent getting this prepped. Annoying.





More stud extraction.




Not pictured was deleting the sequential flapper and actuators. Side note, the new hardware on this thing cost me like $100+ bucks at my local Ace. Damn hardware is getting expensive.




Huge shelf after first assembly, so back apart they came to make that flow properly.




Fixed! Tapered in nicely.




The other port flows nicely too:




Wastegate porting. Going non sequential and flowing these things means I'll be fighting boost creep. And boost creep can be so bad the turbos overspin and nuke themselves. Hopefully this allows me to target/maintain 12-14psi:

Yeah there's a crack, but in the world of OEM FD turbos that aint bad.






I didn't have these gaskets, and they cost a pretty penny. Found some good condition used ones on the forum:




Same process on the intake manifolds, but went easy with this one. Minor porting only.






Primary injectors cleaned/flow tested. Looks like they were fully locked up when I sent them. Came back perfect!




Tanabe medallion exhaust. Should be nice and quiet and I dig the looks.




Going back together. Not pictured was the process of capping off the unused semi-pp ports. You can see the intake manifold has bosses welded up there to cap them off, I used some aluminum sheet to make some blockoffs and they came out great though. All sealed up:




Lots of little **** like blockoff plates on the IM, etc. New rotary performance 2200 rail. Also deleted the fuel pulsation dampener (brass fitting on primary rail), so that it doesn't leak and burn my car to the ground (known issue):




Cleaned surface rust off clutch and flywheel, greased pilot bearing, reassembled:





Getting close..

 

such weird little engines. very cool.

 

Nice! Looks like lots and lots of little things that amounted to lots and lots of hours to get completely dialed in. I struggle with those kind of posts too sometimes. "OK, so I did this thing that took hours and hours of work, but it's kinda hard to convey that through this single photo I took of it." Lol.

Was wondering when we were going to get this update, seemed like every other post on your NA's thread was beginning to start with: "Been making progress on the FD, but here's some stuff I did on the NA in between!"

 

enjoyed reading this - thnaks alot

 

Thanks guys. Still making progress.

Rusty driveshaft and ppf wire wheeled, ospho'd, and painted.




Belts on, still waiting on PS idler pulley, it's otw.




It's in! Not pictured are the banzai racing street poly mounts. I was afraid of poly, but apparently rotarys don't vibrate and buzz like piston engines do, so poly is ok on a street car. We'll see!



Over a year of dirt floor dust. Shameful I know. But seeing it back on its feet was pretty exciting. Also not pictured are the 20mm front and 25mm rear bolt on spacers I added. Gonna rock stock wheels for a while but wanted a more modern stance. I dig the look.




Currently working on:

• Wiring. Got a few injector plugs that no longer clip, so I bought some pigtails to rewire those. I figured out most of the OEM wiring last weekend though. So many plugs I'm not using without emissions or sequential turbo control. Nice and easy.
• Cleanup the rusty downpipe, weld a wbo2 bung, heat wrap downpipe.
• Install rest of exhaust.
• Radiator, IC, plumbing, etc
• Install link g4x into stock ECU case. Install CAN Harness and connect wbo2.
• Install fuel pressure sensor.
• Key on and test all sensors and outputs, make sure it's firing the correct coils and injectors when commanded
• Base timing set while cranking.
• Start it?

probably a lot more little stuff too. This is the fun part though, and I'm really in no rush.

 

Alright guys, another update/dump to get this current. I've been plugging away with most of my spare time (between snowboarding and it being too cold to be in the garage I haven't had as much steam here as I hoped). That said, once again the amount of hours into it doesn't feel like it shows in the update. But it is what it is, I've been really enjoying working on it so no worries.

First, I decided to re-use this CRUSTY *** downpipe, the goal being to keep this iteration budget. I might have mentioned this, but assuming this car treats me well and the engine breaks in and is solid, I do have plans for a single in the future with goals of ~400whp. At least that's the dream setup for this thing. For now non-seq twins and 320whp would be great.

Also not pictured I planed the flanges and they came out buttery smooth, so I don't expect any leaks.




The stock location o2 bung is so close to the turbo it would definitely eat wbo2 sensors, from my experience they need to be further down. So bung added. Harbor freight flux core putting in work again. I have good faith in how this bung came out.





All wrapped up and installed.





Switching gears to ECU install. It goes into the stock case. Pretty! The old FD board is also awesome, crazy tech for that era.




CAN + expander harnesses installed. (Thanks @curly for letting me buy this stuff from you - super nice to be able to hit you guys up for link parts. One day I'll convert the miata!). Just popped these wires out the side of the case with a grommet. Not pictured, I was able to get the ECU plugged in, and UNLOCKED. This was a second hand (unused) ECU but there was still some concerns about it actually unlocking with the provided key. That went smoothly, great success!





Finalized the FP rewire. That larger gauge red cable goes straight to the battery for maximum amperage and minimal voltage drop.




Started slamming the heat exchangers in here. I should have done some before and after, but these both took a lot of cleanup as well. I think most the time on this car is cleaning/spiffy **** up before it can go on the car. I of course went through all the fins with a pick as well for max flow. Heat exchangers are Fluidyne rad and Petit racing SMIC (stock mount IC). Trying to keep a stock-ish layout here and not going crazy vmount or anything. PIcked these up as a package deal for $300.




Of course fresh silicone hoses. All mocked up.




At first I was like holy ****, the radiator just DUMPS on this I/C. Then I remembered it came with a shroud. Also battery box thrown in there to get an idea of fitment.




Shroud is actually pretty awesome. Really shrouds the IC for less heatsoak. Don't get me wrong, that ***** still gonna heatsoak, but the shroud makes it at least acceptable I think. We'll see.




Fresh air from the front is cool:





Onto a battery box. Simple things like this cost a lot for an FD and I'm tired of buying expensive parts. OEM battery trays are $200+ and beat up, aftermarket were $250+ and fit specific batteries. I happen to have a group 26 battery lying around I wanna use on this thing, so I wanted my tray to be big enough for that at least. I stewed over this for a while then remembered I could weld (kinda) so I bought a universal one on amazon for $15, included tie down and all.




Needed a base to mount it to. The pucks are there for the 3rd mounting point.




Couldn't really run a bead here, more of a stitch. But it came out great for what it is, super solid. Also I of course painted it, but here's the finished product.




I actually cut one down for the exact spacing I wanted and of course put a hole through it and a rivnut in the cross bar to secure it. Not pictured, but it's there.




Thanks to @redursidae I've stepped up my wiring game to using DTM everywhere on this car. With his supreme guidance I got the right crimpers, ordered some nice connectors, and did everything in those.






I realized I took no pics, but the finished product you can see here. The cables all neatly stash behind the ECU there and the OEM covers will fit. DTM for the CAN and expander harnesses. Super easy, nice, servicable. Cool.





NOT pictured, but I moved onto coil wiring. The OEM wiring was a 3 coil setup with wasted spark on the leading plugs. (2 rotor has 4 plugs, 1 leading and 1 trailing per rotor). So basically like this:

Spark output 1: L1/L2
Spark output 2: T2
Spark output 3: T1

I'm using a Sakebomb IGN1a Smart coil kit ($$$$$) and it made most of the installation easy. It's similar to miata-land where you wire it right into the ignitor, the kit came with a PNP plug for that. However, in PNP form it actually keeps the old wasted spark setup. Maybe not a huge deal, but in the rotary world wasted spark means less dwell time, which is a big deal since every single rotation of the rotor is a firing rotation, there are no wasted strokes like a normal 4 cylinder which gives things time to cool and coils time to charge, etc. So I decided I best ditch that wasted spark.

This was a frustrating process, to be honest and maybe my first gripe with Link. Of course this is an older link (g4x) they use for the RX7 PNP so this is part of my frustration. However, adding a 4th coil wasn't just running a wire to the expander on the ECU like I thought it would be. There are somehow no extra spark outputs? Crazy.

So with @redursidae 's help, and some posts I found on the link forums we had a plan:

A/C compressor is triggered off Spark4 output on the ECU. The cat overheat light uses Inj7 (yes, there's a light that comes on when the stock cat overheats - I have no cat and no use for this).






While I don't currently have A/C, I have full intention to add it back in on this car at some point and want to keep A/C. So the plan was this:

Re-pin ECU so that A/C compressor relay trigger is Pin 52 (Inj7), re-use Pin 87 (IGN4) to trigger my extra coil. This ended up working out perfectly (after updating the ECU firmware so I could assign spark outputs!) and after re-mapping the inputs in the ECU everything is working.




I ran an extra wire from the Sakebomb coils after de-pairing the batch spark so they were individual and now have proper spark outputs mapped out as per the manual:




While we're talking about wiring I did re-wire several of the injector clips which broke, and the CLT sensor, and a few other things got patched up properly in the harness. This car just like many others from the era clearly had something wired into it. When cleaning up the wires I saw the MAP sensor was intercepted at some point, along with the main switched power to the ECU, and a few other things. Not sure what that was for but I assume some sort of piggyback tuner. I un-did all that and properly crimped those with my new fancy crimpers and heat-shrink/glue-sealing butt connectors. This is a departure from my normal "solder everything" approach after talking with @redursidae and watching some HPA videos I'm convinced that proper crimps are better than solders in the long run. The new crimpers make a banging crimp, a few test ones I did showed that you are gonna basically rip the wires apart before the crimp comes undone, and apparently these are less vibration prone to causing breakage. Funny because I always thought solder was the end-all.

Anyways after all that I was also able to test my injector outputs and confirm those are mapped correctly as well (and basically use this output to make sure the plugs were correctly installed, since the primary/secondary injectors are close to each other and the plugs the same they could easily be, and were mixed up.







Also got my Fuel Pressure sensor wired in. This terminates all 3 wires into the ECU expander harness, all via DTM as well.




Current state of the bay. Ready to be buttoned up now that injectors and coils are installed/mapped correctly and I don't need access to them.




Also got my AEM wbo2 connected. This of course goes into the CAN harness for power/ground/CANH/CANL outputs to the ECU via DTM connectors as well.

 

Quick list of what's left to do before first start/drive/base tune for break in:

Fuel System:

• Fill tank with premix (yes I'm keeping the oil injection system, but I'm also going to premix. And premix especially heavy for break-in!).
• prime the system, figure out which line is fuel feed (I ran all new lines, fuel feed/return are the same size and I honestly don't remmeber which is which. this was always the plan).
• Install fuel pressure sensor in-line of the fuel feed. Install return line. FUEL SYSTEM DONE.

Engine bay:

• Install upper intake manifold (with coils and injectors wired/confirmed, I can install this without obstructing anything I might need to get to).
• Install throttle body. It's already cleaned and ready to go. I didn't mention it but I had to make 1 good throttle body out of two, since mine was missing some parts. It's already fixed/cleaned/ready to install. TPS already confirmed working.
• Install AST and top up cooling system. All other lines are plumbed and tightened already.
• Install intake tubing/filters on turbos.
• Install charge piping for cold/hotside. This includes BOVs which now VTA.
• Add oil. Another thing I failed to mention is that I already flushed the oil cooler with ATF (previous and very reputable shop confirmed the car did NOT have a bearing failure and the oil cooler/lines were OK to re-use). I also have already hooked up all oil lines. So just adding oil is next.
• Crank to set base timing as best we can during cranking state. (I already tested the started and she CRANKS and has lots of compression). If we don't build oil pressure during this procedure, continue to crank and make sure we get oil pressure.
• Ready for first start.

Chassis:

• Re-install some interior plastics, and seats/belts. Maybe just put the whole interior back together, that would be nice. But not required for first drive.
• FIX toe on the front. New tie rod ends are visually toed out, I'll get a string on there and make it drivable at least.
• Another thing I didn't mention, but the car has brakes. I bled the brakes and have a firm pedal. This was after installing braided everything and new pads/rotors.
• I also have clutch! I didn't mention this eitther but I rebuilt the clutch slave cylinder and have a FIRM pedal. Should be good to go.

Then we'll be firing this thing up, setting base timing, tuning idle, then taking it for a drive. The plan is to have @redursidae come down for first start and get a rough-in tune on it. I'll then need to put at least 500 miles on it before we start boosting and get the rest of the tune dialed.

 

Amazing progress! This is such a cool project!! Really looking forward to the first drive

 

Glad to see you got it all figured out, and happy to help you (and others) with Link products.

That is the unfortunate thing about the earlier pnp models, they're pretty basic. Luckily the MX5 (90-95) model has a decent set of expansion pins available, although still no knock or ability to use E-throttle.

The NB2 model came out a few years later for example, and one of the 8-pin expansion connectors has everything you need to run E-throttle. Very nice.

Kinda weird they didn't even pinout all 8 pins on your expansion harness, although you have a decent amount of aux outs and AN inputs pinned to the factory harness. I actually prefer this because I can just chop off the OE plug, install a DT plug, and the OE one usually has 12v right next to it for things like EBC.

 

Getting closer! Very much looking forward to working on this one with you.

and I agree with Curly. Such a shame that they haven’t updated this model to the later schemes. The NB ECUs are amazing.

 

Thanks guys!

There is tons of I/O through the factory harness like you said, that is the saving grace. So many factory solenoids, boost controller, etc. pinned through the factory harness that aren't used. Plenty of I/O in that regard, at least. I'll probably re-pupose the factory boost solenoid wiring for EBC when the time comes. For now I won't be using it at all, just wastegate.

I've barely dipped my toes into the software but it's amazing. Help menus have all the answers, everything is easy to find and clearly labeled. Really a breath of fresh air compared to the DIY MS world.

 

Yeah man, I dunno that seems like some pretty f*cking solid progress to me

Thanks for enlightening us on some of the intricacies of this thing. The factory ignition layout scrambled my brain at first.

Glad the first fireup is in sight! Not that you seem to be too concerned with that lol.