Let us start this adventure with a bit of background. I've owned LOTs of FCs over the years, NAs, turbos, 2+2s, S4, S5s, Ive even had a few FDs along the way. I collected parts to the point where I could probably build an FC from near scratch, but as life would have it I sold all my FCs parts over the years and then sold my pride and joy a beautiful black S5 turbo. Fast forward to a few months ago I was watching Rob Dahm buy a pretty clean 10AE and filled with envy. I had officially been socially influenced, and I had been bitten by the bug yet again. I started looking around for a nice FC, preferably a turbo, and was closed-fist-hit-in-the-face by the reality that prices had skyrocketed. $4-5k for a rolling chassis; who are these people kidding? Being in upstate NY was not helping my case. Everything was rusty AF or just super expensive. I fell into a bit of RX7 depression as I'm guessing anyone looking for an clean FC right now has. But I kept my eye on facebook hoping someone would post up an FC not realizing what they had and I would somehow be able to swoop in before the other vultures snatched it up. Well that didn't happen....instead I found a bit of a turd, but a good turd. The kind of turd you don't really even need to wipe for. Specifically this turd had spent most of it's life in the south so the chassis was clean and rust free. It's a base S5 NA which clearly had spent a lot of time sitting out in the sun. The dashboard and most every piece of plastic in the car was toast, but almost everything was there....and by almost, i mean it didn't come with an engine....or lots of those nice to have parts in the engine bay that make the motor run. Oh! and did i mention it has leprosy? well it does...







So, realizing i'd never be able to sleep spending $10-12k on a turbo FC, I drove to NJ (I know, I know) and picked up the turd and got it settled into my garage where it's going to spend a very long time as it slowly get brought back to life. So I know some of you are bored of reading and still wanting to know why I picked the title I did. Well, sit down, relax and get ready for more reading....

 

So i admittedly left out some crucial background information. A while before picking up the turd, I found a dealership that had a pretty sad looking RX8. I own an '06 shinka as well so I had to go check it out. It was super rusty but the engine started right up and it drove down the road well enough. The dealership couldn't actually sell the car as it wouldn't pass NYS inspection given the rust, but they were more than happy to sell the go fast bits. You can see where this is headed now, and I can hear the eyes rolling from here. The RX8 has the hi-power output 6 port motor and the standard 6 speed manual. My intention is to swap over the power train. I'm lucky enough to be able to use any parts off the donor RX8 that I like, so I'm going to give it the old college try.




I can hear all the angry voices now...."what are you doing to control the intake ports", and the old favorite "you're not going to have any low end, it'll be a dog", and "why don't you have pants on again?". All valid questions. The intent is to use the stock ECU to control all engine functions. Will it work? I don't know...Can i get frustrated while trying? Most certainly!

I've spent quite a bit of time mapping out the stock ECU pins, and it actually all looks pretty straightforward. The only trepidation I have is the CAN communication to the keyless entry system, and maybe the ABS control module.

All TBD at this point. So sit back and enjoy the train wreck people!

 

I'm excited to watch this unfold The opinion on the 13B-MSP swap seems to have changed here, it's more like "It looks tough but is probably worth it if you don't intend to go turbo later".

Is there a reason you can't control the aux ports with a standalone? I assume it's solenoid based.

 

so the 6 port motor has 3 sets of intake valves, the SSV and VDI ports can easily be controlled with a standalone as they are controlled with pneumatic solenoids. The APV (aux port valve), the valve that opens the 5th and 6th ports on the other hand, uses a stepper of some sort from what i can tell. While i think it's 100% possible to control a stepper via a standalone, i think on most commercial applications you'd have to use the circuity intended for a drive by wire system to do it, and I'm not sure if any software would support remapping a throttle output to a map of some sort. Maybe someone with more standalone expertise than myself can chime in on that. Worst case, i believe the APV is either on or off, so an output signal from a standalone to an arduino controller would solve the problem as well.

 

That's interesting, I'm surprised they decided to use a stepper motor if it's only ON/OFF and not something that needs to be opened progressively. I'm not an engineer though.

Yeah, seems like a microcontroller would happily control the stepper and then you'd just need to have the standalone signal the microcontroller at the appropriate time. If it were that simple, I feel like it wouldn't be something that people on the internet gripe about so much.

 

yeah, I'm not sure. It's only 2 wires, so maybe it's more of a servo which is a bit harder to control. Also the FSM clearly says it can not have voltage on the motor for more than 3 seconds at a time, so maybe it's a bit fussy. Either way a micro controller would make short work of it.

 

haltech has stepper controllers meant for wastegates. i was looking at this to control the ports on my s4.

https://www.haltech.com/product/ht-0...r-driver-dcmd/

 

Yeah, on the surface, that seems like it would work just fine.

 

Very cool project!! I think the S5 you picked up is a good starting point! Shame that the 8 that you found was rusty as Nordic Green is a pretty rare color. At least its parts will live on in your car! There are a few guys here on the forum putting Renesis engines in their 1st Gen. You may want to head over to the 1st Gen section and see how they are making the engine work for their car. May help lend some insight. Will look forward to seeing progress on your build!

 

Well you'll be happy to know that the RX8 is being recycled very well. All the body panels/doors/hood and the complete interior have found new, loving homes. The body panels even went to a guy that has a Nordic Green RX8 so it worked out well. i'' go snoop around the FB guys and see if they have cracked the can bus communication puzzle yet. I think that's the only hold up i'm going to encounter.

well while I wait for a few parts to show up and for a few warm days i can be outside to pull the MSP motor, I decided to start working on the interior. I've dreamed of having a S5 with a pristine interior for a very long time. Like most restorations that all start with tearing out what's there to see what's good and not,


some goodies needed for the swap....is that a drive by wire throttle pedal? it sure is! Also yanked the OBD plug as i'd still like the option to talk to the ECU and read codes.


Having the interior out is a great opportunity to make sure the car isn't rusting from the inside out as well. As many FC owners can attest, the spare wheel well, and the floor plates by your feet are the usual suspects. This is the worst of it


While all the HVAC parts are out it was a good opportunity to clean those up as well. If anyone is wondering what the inside of their HVAC system looks like, it's pretty nasty. All the foam is disintegrating and blowing around in the system.


Everything got cleaned, all the foam stripped off and new foam installed. Maybe this car won't smell like a typical 80's car now, haha. Motors were disassembled, inspected, cleaned and re-greased. everything should work just like it did off the showroom floor.


Everything in this car is getting pulled apart, cleaned and inspected...i mean everything.


Even re-dyed the seat belts and luggage straps

 

As I mentioned most of the plastic, especially around the dash, was super brittle. Some parts just weren't salvageable. Mazdatrix to the rescue!



Along with replacing broken plastic, the drivers seat had a pretty nasty tear in the side of the cover. So as one does I figured I'd give my hand a try at reupholstering. Seats removed and covers removed. Thankfully the foam looks pretty decent still.


My intent is to use the stock seats as patterns for the new fabric. Hopefully it works, haha. Everything labeled and seams ripped. This is just the back part of the drivers seat. There's a lot of pieces that make up these covers. much more involved than I was originally thinking.



New pieces cut and ready to be sewn together. As much as I tired, I couldn't find any high wear fabric that looked like the original, so i went with something fairly simple; not too flashy.


Door cards reupholstered to match

 

I did the same thing with my s4. When I drove it home there was zero air coming from the vents. It was all either coming out between the three sections and the condenser was clogged. Also my bypass valve was leaking. The valve, heater core and condenser are unobtainable so I have to figure out what to do with them.

 

I had to do a bit of repair on my heater core as well. Mainly the ends were crushed from some jack a** using pliers to remove the hoses. I can say that if your core is leaky, it's brass so you can re braze the joints with regular plumbing solder. the bypass valve I'm looking for a replacement as well. Might have to take a trip to the junk yard and see if any other mazdas have something similar i can retrofit. I'd love to hear if anyone else has found a good replacement.

also the 1st gen control valves are still available. I might pick one up to see if they have the same travel. Seems like retrofitting one of these might be the easiest option.

 

I'd imagine you could solder the longer hose from the FC to the valve assembly of the FB and swap the bracket.

I'm just going to fabri-cobble a plastic valve in line from a late 90's Honda.

 

those door panels look great.

its been a while, but i'm under the impression that the early Rx8's have an ecu that is cracked enough that you can turn off (some, all, most?) of the error codes for the stuff you wouldn't use if you put the engine in another car.
plan B though is just to use some of the Rx8 stuff, might be neat to have the Rx8 tach in the FC cluster? or you could just use some other ecu, there are/were plug in ones for the Rx8 which would fit the bill too

in any case Rx8 engine in an NA FC seems like a good idea, its 70hp more! 70!

 

thanks. working on the seat covers right now. I have a lot more respect for seamstresses after taking this on!

Yeah, i have heard that anything before '06 and you can send the ECU to RB to be flashed and they can remove all the superfluous stuff that might be a hinderance. The adaptronic standalone in the only plug and play ECU that I know of for the RX8, and it doesn't control the APV motor AND it's discontinued, so i think maybe if the stock ECU doesn't work out I'll try the standalone route. TBD for sure.

I've been diggin into the CAN BUS communication the ECU needs, and I'm hopeful that I can takle this, but this is the biggest challange facing me at this point.

 

Wish I had the time and money to completely redo the interior on my GTUs. would love to have a pristine interior some day. Good luck with the resto. Definitely gonna be worth it, when it's all done.

 

https://www.rx8club.com/series-i-eng...ssport-268037/

 

I've breifly looked into mazdaedit and versatuner back when I bought my Shinka RX8. I should contact them and see if they have the ability to delete the immobilizer signal requirements.

 

So reached out to both mazdaedit and versa tuner. Neither of them offer the ability to remove the immobilizer but I was told that the JSPEC versions of the ECU software doesn't have the immobilizer, so maybe an option there.

In better news, the MSP is out of the donor car finally!


Also, started working on the seat covers. Needs a few touch ups in a few places, but for my first time sewing, they are coming out ok. Hopefully they fit as well.

 

weekend update:
weather has been pretty good so i spent a bunch of time out working on the RX7. Got the old trans and exhaust out of the FC and started mocking up some motor mounts. Like all modern shops i started out with some good old fashioned CAD work....and by that I mean cardboard aided design. Starting with mocking up the mounting interface for the stock motor mounts.


The driver's side mount has a stepped interface


Not a problem, made up some nice aluminum spacers on the lathe real quick so I can use a flat plate for the custom mount.


Engine and 6 speed are tucked in the new location! Notice my use of high tech wood spacers to get it situated where I think it needs to be, and a ratchet strap to get it rotated so the engine is level. You can also see the fancy spacers I made behind my cardboard mock ups



So good and bad news...If i haven't mentioned already this car used to be an automatic, which actually is going to work out really well for me. The good news is the automatic driveshaft is ALMOST the right length for the 6 speed RX8 tranny. The sealing diameter and spline match right up to the RX8 tranny. The bad news, is that it's ALMOST the right length; it puts the shifter about 2.75" farther forward than the stock shifter location. The other issue is that even then, the tranny rear seal is bottomed out on the driveshaft.


So I had 2 options. I make this work, or I buy a custom driveshaft. I thought about it for a bit, and I decided that if I were to get a custom driveshaft made, i'd probably upgrade the diff to a T2 diff, so for the time being, I'm going to roll with with the auto driveshaft and see if I can make it work. Avert your eyes if you don't like to see a clean FC chassis cut up....


It's sitting about 3" farther forward now. The rear seal is still farther back than I would like, but there is some travel available now. Not sure how much I should have, if anyone knows I'd love to hear.


So next is to fab up the motor mounts in steel, and then get something made up for the tranny mount. I've heard that you're not supposed to have the engine, tranny, and driveshaft all in alignment. Any merit to that, and if so,how much offset should you design in?

 

In case anyone is interested I did a bit of forethought into this. I also make spreadsheets for things (nerdy i know) and this could be valuable information for everyone. One of those spreadsheets was trying to figure out what driveshaft would work with the RX8 trans. Sure enough, the numbers line up with reality. With the auto driveshaft the RX8 shifter sits 3" farther forward and the engine will sit roughly 1.125" further back (measured from the rear housing).


better visual:

Also for reference the overall distance from the driveshaft flange to the trans bellhousing is about 66.32" for all RX7 configurations.

 

I like how the engine fits. There was a thread about this swap not long ago and I was under the impression that fitting the transmission would be a pain since it's shorter. j9fd3s mentioned that the engine sat so much lower you could push it back, and he was right. I might have moved the engine forward 1.25" instead and then swapped the TII transmission, which would put the shifter in the stock location though. Also means you can use stock transmission mounts and help you locate the engine. I have no qualms about modding the chassis, it's just that getting the interior to look right is a pain later because the now shifter location collides with the dash.

Seeing a 13B-MSP FC come to fruition is really cool, so many people talk about it but watching it in progress is something else.

 

yeah, I mean it's a cost thing really. A T2 trans is $1000 now days and is pretty massive overkill for a stock MSP. I probably could have found a N/A 5 speed manual for cheap, but I already have the 6 speed and even the stock MSP power levels are iffy on an N/A trans. Worst possibility is I hate where the shifter sits and I get a custom driveshaft and bring it back another 3". I know Mazdatrix makes them for a decent price, as do a few other reputable places.

Well hopefully I can make it happen. I know I'm not the first, but I don't think I've seen anyone do it with the 6speed trans before. I guess the whole point of this thread is to document the process and to see if it's a viable alternative to trying to get a jspec motor. If i'm successful hopefully I can provide enough info for someone else to take a crack at it and maybe salvage some of the rolling FC shells that are popping up everywhere.

 

ok...new plan...not sure why i didn't think of this to begin with. Chop out 3" from the auto driveshaft. Apparently this is a pretty common thing to do with muscle cars back in the day, and if done right doesn't require balancing again. Even if it does, it's got to be cheaper than a custom driveshaft....