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Long time lurker, first post here!
Have owned a handful of rotary cars. Couple FBs, an FC. Owned an Rx8 a couple years ago and loved it. I'm currently in the process of putting the rx8 rollerskate under an 06 NC miata. Build thread will be started when I accumulate enough posts to do so. Below are a few shots of the rx8 subframe going in.
Spent the week making some progress on the Renny NC.
First up was the was PPF. i wanted to use the NC PPF as it's alright the correct length. I was hoping that it would just mate right up, but unfortunately i was mistaken. The one other instance i've seen of this swap with any sort of photos was a thread on rx8club where the builder chose to use the RX8 PPF. I picked one up, so i'm keeping that idea in my back pocket, but for now, i loved the idea of using as many OEM components without modification as possible. We'll see how it goes.
NC PPF against the rx8 transmission
(yeah, i know the PPF is upside down in that last one. took me a while to realize )
I started thinking of ways to fasten the rx8 transmission to the NC PPF. it seemed simple enough that i could make a small bracket or cnc a chunk of metal to "relocate" those bolt holes.
Took a rubbing and spent a few days fumbling through learning CAD to wind up with this lovely thing. Obviously the 3d printed parts are just for prototyping.
Next up i'm starting on wiring. Still exploring options at the moment for this problem. I have the steering column and gauge cluster that will need to be figured out as well in this realm. Current plan is to strip the engine harness out of the rx8 loom, and replace the engine harness in the NC loom. I'm not 100% sold on the idea at the moment, but maybe i'll come around to it, or hopefully come up with a better alternative. NC harness Rx8 harness Both have grommets with this nasty rubber cement filling them up. cutting it away is a pain (mostly) stripped down of tape on the NC harness Rx8 harness. more of the same mostly finished peeling all the rubber cement off the individual wires, so that i can start stripping things out of the harness
Over the last few days i've been working on the wiring harness. most of the time was spent referencing the FSM for both cars. and picking and choosing which side to use, NC or Rx8. Had to cut more wires than i care to admit, but the majority of them have been depinned from their original location. There are a handful of circuits in the rx8 harness that have no analogous in the NC, so those will need to be created manually.
WIP nasty rubber cement goop on the grommets. this took a long time to clean up Both harness ready for joining
I'm about finished with the wiring harness for now. It still needs a bit of work, but i can't make much more progress until i have the engine to test fit it. Of course it'll also need a fair bit of tape as well.
The other thing i started working on is fitting the radiator. Going in a little blind as i still don't have an engine, but it seems to clear everything just fine. I'll likely be upgrading to a thicker one for the final install, this is my OEM NC radiator, mounted on NC lower mounts.
Rx8 Subframe with NC miata lower radiator mounts fan shroud fits too.
I'm going to be hanging a FC oil cooler in front of the radiator as well. which is the original reason i installed the radiator. trying to bum a spare NC cooler from someone locally so i can design up the part.
Still yammering to myself here, but i made a bit more progress this week.
NC steering column (left) Rx8 Column (right) The rx8 column didn't quite fit, but a couple new holes in the dash support fixed that up. cluster and dash also needed a bit of trimming, but this fit right together.
Something that took quite a bit of time, and has nothing important to show, is mapping out the wiring for the gauge cluster. As it turns out, all the existing NC wires go to the perfect place on the RX8 cluster, and they use the same connectors as well.
There's a handful of wires in the Rx8 harness that simply don't exist on the NC tho, so a few wires will still need to be added. Namely, the second fuel level sender.
Been stressing out about my speedometer/gearing being wrong, so i went and picked up an RX8 LSD, axles, knuckles. I've heard of NC Miata owners running this exact setup, so i figured it wouldn't be that hard to fit it.
NC ppf on the rx8 diff this shows the spacer required to fit the NC ppf to the rx8 diff These studs need to come out of the PPF. I used two NC PPF bolts backed up into either other simple spacer for the rx8 diff fully assembled dry run of the RX8 transmission and differential with an NC PPF and driveshaft
I couldn't help bolting all the parts together to confirm that i'm not crazy. As it turns out, everything bolts up just like i thought. I bought an engine last week, should be here on on Thursday.
The engine came in the other day. Been chugging along on slapping everything together. It looks like everything is going to fit well. There were a few things i was unprepared for here, but nothing i can't deal with.
Loaded the engine and subframe up into the car checking fitment. the shifter hole needs to be made slightly wider. not exactly sure why it seems to be so far to the left in this picture. the turret is slightly bound on the hole itself, so it's possible when i make the hole bigger, it will center itself in that dimension. NC Driveshaft fits Exhaust is kinda close to the side of the tunnel here. it's not touching anything currently, but it's pretty close and i don't really want it catching on fire. I'll likely bash the sides in a little bit for got luck. also started draping the wiring harnesses all together. This is going to take forever.
Best of luck getting everything sorted over the winter. I’m interested in where this build ends up.
Thanks! i'm hoping to get all the major systems functioning by the end of the year, so i can go in and tie up all the lose ends over the rest of winter. My hard deadline is August 4 of '22 for Miatas at the Gap. Here's hoping i get it done by then.
looked at my spare trans. dunno how i never noticed this, but the shifter has a kick to the side. here's an angle of it inside the miata threw all the major components together to see how everything felt. if i didn't know better, i'd say it was meant to be here.
i'll probably have a friend of mine custom make me a upper shift boot. the OEM Miata one prevents the shifter from going into 2nd and 4th gear easily.
progress report this week. picked up more parts from the donor car, most notably the air pump, fuel pump resistor and baro sensor.
I grabbed the rx8 airbox but i just don't like how it fits in the engine bay. instead, i'm going to modify the NC one.
I started with by laying the two harnesses over eachother. most of the wires are in the right place, but quite a few will need to be extended.
I also picked up a backup harness to reference as i build.
Not pictured below, but i got the fuel lines sorted as well. the NC miata and rx8 share the same hardline locations, so the stock rx8 fuel hoses worked perfect.
On the note of hoses, i didn't grab good enough pictures, but the NC lower radiator hose fits the Renesis water pump well. one of the hoses from the overflow tank also
line up very well. I'll still need quite a few hoses for stuff such as ABS, and both heater hoses.
running the rx8 ECU in the stock NC location loaded all the components into the engine bay to pretend it's done the rx8 fresh air tube fit with a bit of trimming. The NC airbox lines right up with it
Thanks, my plan is to have the majority of the fabrication and such done by the end of this year, then time for a fresh rebuild and little touchup over the cold months
Originally Posted by 200.mph
cool project. i would ditch the vfad tho
i'm running all the OEM components up front since i'm building the wiring harness from scratch. after that, i'll start removing components. I have emissions testing where i live as well, so i technically am supposed to keep everything in the intake system function.
Doing some research today to check some things out before i go messing stuff up. cracked open the FSM and am looking at the fuel pump specifically. I finally understand how the high/low pressure relays work after looking at the diagram.
i'm not exactly sure why they put the resistor pack in the engine bay, but it's no big deal. The thing i'm sure i do not have is the "condenser" that exists in the rx8 fuel pump area. I'm nearly sure it's simply a capacitor to ease the transition from the low pressure mode (which i'm guessing is about 9-10v) to the high pressure side which would seem to be full voltage. The NC fuel tank is "normal" such that it doesn't need all that suction pipe business, so i'm pretty sure all i'll need to do is find myself a condenser and throw it in parallel with my upgraded NC pump and the high/low pressure circuits will work. Fuel Pump wiring page out of my FSM
Another thing i found while i was rootin' around in here is how the auto leveling headlight system works. Kinda funny that the NC didn't come with that since it's all the same components otherwise as far as i can tell, but either way i don't need it, so it got stripped out of the harness.
It seems to work by reading the input of a rotational sensor at the sway bar, and by moving the motors in sync with that signal. not complex, but i did just find it sort of funny for some reason.
Haven't had much time to work on the the Miata as i had to go out of town on a work trip, but i did manage to get an hour or so in this weekend.
Mostly focusing on where wiring is going to go. I found a company that makes an engine extension harness, so i emailed them about getting one made for me
in the length i need.
The rx8 engine harness doesn't reach the NC ecu location, so i'll need to make or buy an extension harness
Found a spot for the electric power steering module. will need a bracket of course.
I was originally planning on using the oem NC airbox, but i decided it would take too much work, so i mocked up this idea. i'm not a huge fan of pod filters, but if i seal the box and plumb it into the oem rx8 snorkel, it'll be a proper "cold air intake"
Another week of almost no progress on the NC. Still managed to spend $1500 about it though. Grabbed a K&N Air filter, CSF 8066 oil cooler and the CSF big aluminum radiator for NC, as well as some other misc stuff.
Bought a CSF #8066. need to fabricate mounts for it. Also picked up the K&N Typhoon intake. it fits pretty well, but i'm going to have to fabricate the sheet metal for the box as well.
Still a lot to do, but most of it involves plumbing now. i bought a full silicone hose kit for rx8, hoping that at least a couple of them are worth the buy.
Were you adapting the K&N to draw air from outside the engine compartment? I thought I saw an earlier post with your own air box design. The K&N pulls hot air.
Damn. Impressive work. I definitely interested in seeing how this project progresses. I've long dreamed of a renesis-powered miata. It seems like the engine would be fantastic with a lighter car.
Were you adapting the K&N to draw air from outside the engine compartment? I thought I saw an earlier post with your own air box design. The K&N pulls hot air.
Yeah, i'm only using the intake tube and filter from the K&N. i'm going to fabricate and seal a real airbox and plumb it to the OEM cold air tube long term.
Originally Posted by axiomatik
Damn. Impressive work. I definitely interested in seeing how this project progresses. I've long dreamed of a renesis-powered miata. It seems like the engine would be fantastic with a lighter car.
Got sent out of town on work again last week, so i missed my window to get any work done on the NC again. I did manage to grab myself a TIG welder tho so i guess there's that. I was originally hoping to complete this project without needing to weld anything as a challenge to myself but the time crunch is starting to set in.
Waiting on some accessories to come in the mail, but i'm hoping to knock out the oil cooler mounts this week.
Last edited by pls_pressY4pie; 11-03-2021 at 02:42 PM.
Reason: broken attachment
Very neat project! Don't forget that the brake system on the rx8 is just a larger version of the NC's. If you have aftermarket wheels that can clear them, it would be worth the upgrade.
Very neat project! Don't forget that the brake system on the rx8 is just a larger version of the NC's. If you have aftermarket wheels that can clear them, it would be worth the upgrade.
Yep i'm running the rx8 brakes all around. Stock NC wheels actually clear them. have them installed right now.
Got another small update after being sick all week. I went and picked up my adapter to run the NC PPF on the rx8 transmission. Unsurprisingly, it fits perfect. machinist did really good work with the part. it's a shame no one will ever see it.
I didn't get a chance to fit it to the car yet, but i threw it on my spare transmission to double check. I'll need to run to a Fastenal and grab some m14 bolts to fasten the adapter up.
Haven't forgotten about this project, just had a little bit of the ole ADHD kick in and decided i wanted to go drifting next season... so i bought another project. Classic blunder i know.
Garage is getting a little crowded with all this bullcrap going on. Stay tuned, we will return to our regularly scheduled programming soon.
08-15-2021, 08:26 PM
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