Well if you could educate me some; how is it that those PIDs exist in the ABS module, but are not on the CAN stream.

I’ll also rebuke myself some, because over the years we’ve had a lot of people come on the forum talking about the things you’re doing, but apparently lacked your ability to get there. Clearly I misjudged you on this, like where this is going, and am looking forward to your future posts.

So the ABS module is on the CAN bus, but doesn’t seem to want to respond to diagnostic addresses like one really would. I tried. I have no idea why they chose to do that.

Looking closer at the wiring diagrams we can see a single line diagnostic wire going to the OBD port. Usually in older vehicles, which I guess nowadays this RX8 is, they used a K line ISO9141 which is a single wire serial protocol. It runs at 10.4k baud as opposed to a 500k or 250k CANbus. In 04 there was a lot of transferring over to CAN for communications in vehicle, but some systems still kept the old methods depending on whatever was on the market. While at first I wasn’t complete sure this was what that line was, I was pretty sure because I get paid to do this kind of thing these days.

Luckily I knew this ABS module was a similar, if not the same, module used on some Ford cars of the same era so using a generic autozone OBD reader I was able to confirm the line was an ISO9141 line by querying the ABS module as a 2000 or so Ford Focus.

So yeah. Basically tl;dr it’s a different data bus than CAN because that ABS module was cheap cheap cheap at the time.

More DAQ stuff. Ported all my code over to a new controller which runs at 600MHz as opposed to 24Mhz... not a bad improvement.. though we likely won't actually need all the horsepower since we are limited by the bus speed.. but I am hoping to integrate some CAN logging into this device as well.

Anyways, tonight I worked on refining some code for easy send/receive and also converted data packets into actual engineering units. I'm not sure my scalars are correct...but I think the G sensor is. MC was something I think I saw based on a service tool.. so it may be incorrect.

Some videos of the data collected with a bunch of debug stuff still enabled.. sorry for the Lat G stuff.. it's pretty hard to get the value to move off 0 just by wiggling around as you can imagine. Looks like I got it up to .03G! Yay Recaros and their holding ability... more on that in a moment.

MC Pressure:

Lat G:

Next steps are to see if I can do multiple PID requests at once, and to see if I can poll data instead of having to request the PID everytime. This will make my software life easier... as well as cut down bus traffic by over half and allow for faster data refresh!

Yay!

Recaro RS-GK Driver's Seat

So tl;dr aftermarket seats suck to fit into an RX-8 if you're not willing to custom make your own brackets.

I tried to fit a Cobra Suzuka seat into the car using a Sparco mount. I kind of wanted to use a fixed mount.. but I'm not a tall dude so this deemed to be not quite possible. When I put the Cobra on the sparco rail it BARELY cleared the "B pillar" and was hitting the door quite a bit. When I put the Sparco rails on, it didn't even try to work. 0/10 would not reccomend sparco rails by the way.. were binding up brand new out of the box.

Anyways, this led to to try to find a new rail that was smaller and that I could fit the seat on. I decided to get a Recaro mount with integrated rail.. this was because I knew it was short enough to fit the seat, and I knew it could adjust it so my little legs could reach the clutch. Along with this I bought the offset Recaro rails. This also gave me the option that in the event the Cobra just wouldn't work (title of the post kind of spoils this surprise), I could enact Plan E... or F... or whatever and just buy the Recaro I was trying to not spend the money on initially.

The Cobra almost fit on the rails.. but it was JUST too wide and didn't quite fit.

So then I just bought the RS-GK from Evasive and didn't look back... and let me tell you I am 100000000% glad I went this route. EVERYTHING bolts right on up.. it's got harness eye holes in the bracket I can use.. and the seating position is just 100% perfect for me in the RX-8. You can even see just the size difference in the seat itself. Inches are miles when it comes to seat fitment. The weight of the seat is also waaay less than the Corba (I didn't weigh them).

I tested helmet clearance and boy.. I don't know how you taller people fit in these cars. I had about an inch and a half on the left to the A pillar and maybe 2-2.5 inches to the headliner. I am 5' 6 on a good day.. man...

Anyways.. I am in love with the seat and just need to get some harnesses on order.

And hey, at least I have a passenger seat now!


https://cimg5.ibsrv.net/gimg/www.rx8...e9318ed39f.jpg
https://cimg6.ibsrv.net/gimg/www.rx8...098f585e0f.jpg
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https://cimg3.ibsrv.net/gimg/www.rx8...7c8f2a0dcb.jpg

anything with shoulder wings requires some effort

the advantage of an aluminum seat though is they can be bent in a bit, which for most people they’re a bit wider than necessary and then that also can make for a better fit. Making custom mounts by using the OE seat slider and adding tabs helped in my case too.


https://cimg5.ibsrv.net/gimg/www.rx8...ef8f933f7.jpeg

Little more digging on the sensors today... spent way too much time to have a seemingly MEH level of improvement.. but I promise it was time well spent.

Got the driver running at a 40ms update rate (can't do any faster.. think I am hitting bus limitations.. 10.4k bus at half duplex without a "talk until interrupted" is trash). But both data figured being queried at the same time.. all with somewhat proper tasking and parsing.


Now to get it to the front end.. and log the data for some meaningful use.. the easy part is done.

What slider and bracket did you use? I'm 6'1" but mostly legs and using the same half cage. Trying to figure out seating right now and worried about headroom and width. I pulled my sunroof and headliner out though so i have a bit more room. Stock seat is fine height wise right now.

The Recaro ones.

I think taller people gain clearance because they won't be as close to the wheel, as thus their head won't b as close to the A pillar/roof. Here's to hoping for you at least!

not necessarily due to various factors, but I’m not overly tall and in order to be up close to where I prefer the steering wheel position to be relative to my upper body had my knees all jammed up in the dash. Then the roof and A pillar are crowding in too. So extending the column/wheel position further back which then allows the driver position to be back more is going to help imo.

Thanks to you both. Thoughts on the Buddy Club mounts with slider? I had originally planned on using the Planted mount with a slider and side mounts but i like the idea of just buying one unit even though the side mount on the buddy club aren't as rigid looking as a separate side mount. I just worry about height and simply fitting a seat in. I come from the BMW world where there's usually plenty of space and also people have tried everything given how many of those cars are on the track. I have access to a few different seats to test, just no floor mounting plates yet.
Should I just get the Planted mounts and some nice side mounts like the Recaros with a slider?

I'm not going to run a passenger seat at all, i don't think.

Oh and sorry for hijacking your thread, i'm following it closely.

Man I've been busy with work and tuning my Impreza, the RX-8 hasn't gotten much attention.. let alone been to the race track -_-

Either way, I do have some updates on the integrated gauge screen that are fun to mention:

Got the sensor over CAN stuff all done up and an old sandwich plate and Defi sensors I had laying around for a Subaru (yay same thread sizes) popped on the sensors and ran the wiring in car to my unit to read sensors and populate them on the bus. Don't worry, I tidied up the wiring. The controller for the sensors was STUFFED full running a full RTOS and I think peaked out at 98% RAM usage... not a bad result from a $4 controller though!


https://cimg5.ibsrv.net/gimg/www.rx8...d3704c0e3e.jpg
https://cimg6.ibsrv.net/gimg/www.rx8...6efeb41817.jpg

The result is pretty good! I need to change the software to look at an external reference voltage for the ADCs instead of living in dream world where everything is 5V, but aside from that I'm super happy.


Next is to implement my logger which only about halfway works right now haha.

was wondering about you, figured that her holy whacko-ness the governor was the issue

pretty cool, but I hope that needs calibrating and isn’t your true idle oil pressure reading :uhh:

Definitely think it needs some calibration, like I mentioned I just have the ADC Vref set to 5, when in reality it's probably closer to like 4.6-4.8 which is definitely enough to throw off readings on the low side. Doesn't look like it's far off though. 4.8 bar or so at "high" RPM seem okay, and 1.8 idle may be a little low, but sounds about right. I'd like to see idle around 2-2.2 bar but I have no idea what these engines like to see.

even OE is way too low imo, most people don’t appreciate how oil pressure benefits a rotary engine in ways that exceed a piston engine.

Holy hell I just put in way too much work to have this little to show, but the precedence for the work ahead makes me happy.

tl;dr working a vehicle data logger, finally got the lat G sensor being queried and written to a .csv file on an SD card for easy data review.

Code snippet:
https://cimg9.ibsrv.net/gimg/www.rx8...c6d918a565.png


https://cimg6.ibsrv.net/gimg/www.rx8...8e4226da24.png

Me just shaking the car while doing a quick log.

Refresh rate will be improved, I have artificial delays in just for development sanity that I can get rid of.

Next on the list:
-add second ISO9141 PID (MC pressure)
-add a rolling filename, easy just didn't enable it in order to clog up the SD card for development
-roll in the CAN data, just need to add some more hardware

Suuuuuper stoked!

More success at a two PID query tonight. Abysmal update rate, but at least you can see the change in MC pressure over time with 3 brake applies.

https://cimg7.ibsrv.net/gimg/www.rx8...5e1d45c039.png

it reminds me of the Pac-Man days :suspect:

Evo R Endlinks

So, these seemed like the goto endlinks for low RX-8s.. was a bit disappointment to see they shipped from Thailand, but it's better than China and they seemed pretty decent for install when I get em. The website did say I would receive a rotor plush toy with my order, which unfortunately I did not! Big sad, how am I even supposed to install these now!?

Anyways, install was super pleasent after I spend 2 hours trying to get the destroyed factory endlinks off the rear. One was blown completely out (read: I had no rear swaybar), and obviously the were rusted to hell so I have to get creative to get the bolt off. I've come to accept the fact that literally every I haven't touched yet on this car will be a huge pain in the ass to deal with. Luckily, spare Subaru bolts came to the rescue again on the new endlinks.


https://cimg7.ibsrv.net/gimg/www.rx8...cd102601f3.jpg

https://cimg9.ibsrv.net/gimg/www.rx8...9fa80880d6.jpg

Much nicer with these than the stock ones. No endlink preload at all.

I did tighten fully with the car on the ground, but that doesn't make for better pictures.

Couple little things:

Not going to dedicate an "official" post to this, but it just shows how literally EVERYTHING I haven't touched is a problem. The PO couldn't even put the battery box on with all the bolts. Just couldn't be bothered :| So I threw some new hardware in there so that the battery would be properly, and SAFELY held in. I do have a optima coming in shortly because this battery doesn't really even fit.. and I've had a non AGM battery leak before me on the track. Just don't want to deal with that...


https://cimg9.ibsrv.net/gimg/www.rx8...bf7362fc2c.jpg

Also finally decided I should drill holes for the MS skirts to get mounted like OEM.. boy is it much nicer fitment and less of a worry they will take off at speed.


https://cimg0.ibsrv.net/gimg/www.rx8...5ea432c22f.jpg

evo rear links are ok, but the front ones not so much, mostly because the loading is so much higher in the front

think I have the front pair minus one joint end if you want them for spare parts.

you need to be sure to put anti-seize on every thread of every bolt on this car to avoid those kind of removal problems. I’m sure it was already salt corroded beyond hope before you bought the car though. For the high heat/exhaust stuff though you need a nickle type anti-seize though because the std stuff won’t cut it. I just put that on everything now.

.

Schroth 6 Point Harness

So this actually took a bit of time to get all the parts (and motivation, work takes up most of my time) to get this in. But hey, found a deal on a set of FIA2020 Schroth harnesses. I intend to throw the otherside in with another fixed back seat.. but that's for another day.

Mounted the shoulders on the harness bar. No issues there.

For the right side mount, the Recaro bracket has a nice convenient loop for the harness to pop on to and is nicely welded to the frame of the sliders. For the left side, I was able to track down some M10x1.25 eyebolts to pop into the OEM mount bolt hole. Had to shop them from Japan and they weren't super cheap.. but it made my life WAY easier, so I bought some extras in case I ever need em.


https://cimg8.ibsrv.net/gimg/www.rx8...6e11623857.jpg

For the bottom holes I kind of had some issues, and my solution probably is not one I would recommend to a friend. So the issue was that I am pretty short, so the seat is pretty far up. This put the ideal 10-20 degree mounting location right on top of the frame bar under the seat. Not really exactly easy to mount anything too without really starting to chop. I figured I'd settle for some more angle and just write my groin off if I ever really binned it big time so I mounted the eyebolts behind the bar. This would also allow for anyone taller to drive the car safely.

When I started to drill holes the recommended 100mm apart, I realized after I had already drilled the centered up first hole that if I drilled in the second hole I'd be right on top of the fuel lines.

DOH

So again, I settled for the bolt being MORE than 100mm apart and a bit off center of the hole in the Recaro. Once again, I don't think I would recommend this solution to a friend, but it's going to be good enough. It has to be now.

I'd like to go an redo these bolts when I can get a chance. I'll have to do some welding, which fine.. I just can't waste time worrying about that now.
https://cimg5.ibsrv.net/gimg/www.rx8...c8de5e0180.jpg
https://cimg7.ibsrv.net/gimg/www.rx8...a7d2f60c7a.jpg

With everything in, I ran the liner on the crotch hole in the Recaro and boom!


https://cimg5.ibsrv.net/gimg/www.rx8...b133c77008.jpg

I need to double check my loops and add more length to the left side, but other than that I'm super happy with these!

FIA 2020 will expire this year, but as long as I don't get involved in W2W I should be good for the people I race with. Also gives a good excuse to go with some 2in shoulder belts and get a proper HANS

Stock belts are still kept in... well.. mostly because I'm too lazy to pull off the rear door card. My lack of motivation is starting to show and I really need to change that. But work and my Impreza have been eating up a lot of time (yay tuning for a new turbo!)

Waaaaaaaaay ahead of you. If I enjoy racing this chassis (ONE OF THESE DAYS) then I'll likely end up picking something new up from the south and junking this one. It's pretty awful, no other way around saying it.

I have the perfect chassis for you then ...

Mazdaspeed Towhooks

Simple enough. I need towhook and who doesn't like a lil bling :wiggle:

Found a solid deal on some genuine used ones. I was just gonna rock the stockers, but hey.. gotta somehow get dat Instagram clout.

https://cimg1.ibsrv.net/gimg/www.rx8...ca03a851f7.jpg
https://cimg0.ibsrv.net/gimg/www.rx8...709a1780b6.jpg

aaaaaaaaaaaaand finally a corner balance.

There's much more work I can do on the balance.. but I was getting hot and needed a beer. I've still got the car on the scales so I can play with it more tomorrow.

Pretty not happy with the overall weight and corner balance (balance gets a tad better with me in the car). It weighs more than my Impreza! To be fair, I have pretty much only added weight and haven't put any sort of focus on reduction.. so maybe I can work on that as time goes on.

I am happy with the F/R weight... I'm okay with 48% rear because the rear spoiler PROBABLY should balance that back out. Or whatever. I don't know, I'm a software engineer. Another to be fair, I am coming from my Subaru which had a F/R weight that was laughable in it's best state. So it's nice to see some better numbers.


https://cimg9.ibsrv.net/gimg/www.rx8...d93f00b874.jpg
https://cimg1.ibsrv.net/gimg/www.rx8...c26829e3bb.jpg
https://cimg0.ibsrv.net/gimg/www.rx8...6a9b231610.jpg

Speaking of wings... I did a little try at some basic aero testing. Turns out, I suck at this and my camera angle and string population was terrible. I did at least look at speed as a factor here though, so hey gimme something!

tl;dr all I truly learned was that my test was shit, and my uprights cause a ton of drag.

Video:
Youtube compression sucks too and you really can't see much at all.

And some basic conclusions, however biased as hell to confirm my hypothesis and shouldn't be taken as fact... like even a little:

https://cimg7.ibsrv.net/gimg/www.rx8...23a755992e.jpg


I'll work on this more later.

https://cimg3.ibsrv.net/gimg/www.rx8...f7208fe4bd.jpg
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Finally got to the track today. Updates/thoughts soon. I am beyond pleased with the car!

looks good, but be careful parking on grass like that because it would’t be the first time a hot RX8 exhaust kindled and caught itself on fire ... :uhh:

Dang, still need to make a post about the track... everything went well and only broke a few minor things.

In the meantime, check out my REALLY ghetto EPAS setup working on a bench:

Grattan Raceway - June 20, 2020

Oh man, finally able to have some time to reflect on this. First things first I guess I should start out by saying I didn't actually expect to be going to the track this weekend, but the stars aligned, my friend offered to trailer the car, and was ready to wheel the RX-8 around for the first time with full expectation of having a subframe fall off at over 100mph.

Well, luckily none of that happened and I am happy to report the only thing I don't like about the car is the lack of power! The thing has SO much grip it's insane.

Let's start back at midnight the night before I had to be up at 5am to tow the car to Grattan. The car wouldn't fit on the uhaul we had rented.. too low.. bumper was hitting.. and the bolts for the roll bar were extended down like 1/2 an inch too far. I KNEW that was going to be an issue when I had first installed it, and here we are at midnight trying to load the car on the trailer.

Took an angle grinder to the bolts to shorten em a bit, and that did the trick.

https://cimg2.ibsrv.net/gimg/www.rx8...c428e1b666.png
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Finally, the stressful part was over and I could do my shakedown.

Another thing to note was that I had:
-Never driven a RWD car (that I owned) on track
-Never driven at this track
-Driven the RX-8 about a total of 30 miles before today
-Eyeballed the alignment

A lot to think about.

Either way, the car did great. There was tons of grip.. and I couldn't make it go faster to use it all. The brakes are fantastic, the suspension needs some attention.. but that could just be an alignment.

The track was even better, such good flow and height changeups.

It was between 88-92 ambient the entire day, and my only complaint was that I did get water up to 235*F before backing down. Definitely need to address cooling (more on that in a bit). I wasn't able to log engine parameters or anything else except bad time timing with my phone. Kinda bummed but I didn't get it all done in time. Reasons.

Here's a session my lap timer did manage to work. Notice the awful interpolation of speed/Gs. The 1Hz GPS though seems to work better with a slow car though!


Alright, so what's the plan moving forward from this shakedown

Addressing cooling:

-I want to get the Racing Beat REVi and duct out of there, make more room for airflow through the radiator. I have a plan to chop up an AEM intake for (probably less power, oh no -1hp!) routing through the bumper.
-Battery moved to truck, again more airflow through rad
-Ordered a Mazdaspeed replica bumper, should suck in more air in theory?
-Changeover coolant to water, blehhhh will do this eventually
-Turn fans on at lower temperature with the ECU cal (seems to be common?)
-Stock undertray goes back on, this LRB shit is literally trash.
-GET MY DAMN GAUGES IN, at this point I may give up on the CAN integrated display and just slap some Defis I have laying around in.

With all these things done, I can then dive down the other alleys of water pumps and thermostats and blah blah all that.

Suspension:
-Align the damn thing properly
-Sway bars, little too much body roll for the spring rate IMO
-Replace some bushings, eventually

Would also like to try and get rid of some more weight, but I also would just like to keep driving the car. In absolute love with the chassis!

Some more glamor shots from my friend who's SUUPER handy with a camera
https://cimg1.ibsrv.net/gimg/www.rx8...1d067bb75f.jpg
https://cimg7.ibsrv.net/gimg/www.rx8...79539e2ab7.jpg
https://cimg5.ibsrv.net/gimg/www.rx8...543274233c.jpg

And of course, you gotta capture the popopops!

https://cimg2.ibsrv.net/gimg/www.rx8...eb5c9c66b2.png

Great to hear how much you enjoyed it after putting in so much effort .
You should have a read up on airflow theory .... It's less about how big the opening is and more about holding the air you do capture so it goes where you want it .

Yeah! Ducting would be really nice to properly do, and I am looking into it.

I've got a pretty rad 3D scanner at work I want to borrow for a weekend and get some reference geometry and start cadding some stuff up.

In the mean time, being a bit less scientific and more "practical" I think just removing the airbox and battery in the way of the airflow from the rad should at least give me a fighting chance. The MS bumper was mostly for looks anyways :wiggle:. I did go out and buy some OEM "fog light" brackets so that it can channel the air properly to the oil coolers too. I hope the rep bumper works with them.

Some other stuff I have been up.. dzus fasteners on the undertray + quick latches on the bumper should make removal and install super easy.

Kind of just mocking this one up while I wait for the MS bumper.. don't really like the side latches, and the corners obviously still need to be addressed, but it definitely makes it easier to remove the bumper. Will think this through more with the new bumper. As you can also see, the ebay quick connect buttons were tried.. but a huge fail. I don't know, this is my first time building race car stuff! Mud guards will also probably come out, unless someone can convince me they help channel air through the coolers and brakes better.


https://cimg8.ibsrv.net/gimg/www.rx8...54a54a8b43.jpg
https://cimg0.ibsrv.net/gimg/www.rx8...8a294aaea8.jpg
https://cimg1.ibsrv.net/gimg/www.rx8...d8e6647333.jpg

Also in my practical attempt at better cooling, I decided I should remove the AC. I can't recall why I didn't before when I did the Koyo... but it's all gone now, lines, compressor and all!

https://cimg6.ibsrv.net/gimg/www.rx8...0ccff79f92.jpg
https://cimg8.ibsrv.net/gimg/www.rx8...46a2d60023.jpg

Oh, and I removed the CD player! NOW we are good to PROPERLY race without that weight :hahano:

I just spent DAYS deliberating over this myself. I actually drive mine around a fair bit but had cooling issues last time on track as well so finally bit the bullet . Almost got a face full of compressor oil for my trouble..........didn't realise how much pressure they hold !

he’d have been better off clearing out all that junk in the front of the engine bay

Waiting for someone to sell me an AEM intake. Really don't want to take the $400 plunge for some tubes and couplers just to modify it.

Also don't want to spend time making it all myself.. so.. here we are.

https://www.rx8club.com/series-i-aft...9/#post4922847

yeah, an AEM is not really a good intake imo, you can build your own better version for sure

given your flare to get stuff done I don’t really get your attitude on not doing it yourself


.

Yeaaaaaah just a time vs money thing here. Would take me twice as much cost in my time for me to make something on point, though I could justify it by refining my aluminum TIG skills... hmm...

Either way I got the 90 degree 3.25in aluminum tubing in the mail today.... so..probably just gonna end up buying one in a few weeks when the new bumper arrives.

except you need 3.5” OD x 0.063” thickness tubing instead

Aw c'mon, you gotta try harder than that to scrutinize everyone..

https://cimg5.ibsrv.net/gimg/www.rx8...1e8d070ff0.png
https://cimg8.ibsrv.net/gimg/www.rx8...20899a7aec.png

I’m not scrutinizing anybody, I’m sharing 15 years of experience with you. I’ve built pretty much every variation of CAI possible for this car. You can go to the DSP thread to see my latest version.

Thanks for making my point though; what part about “it’s not really a good intake imo” didn’t you understand?

The OE Mazda tube is essentially 3.5” OD x 0.063” wall thickness (86mm or 3.375” ID) and is very short. As an engineer you should understand that with a tube length 6x (just guessing) longer that the last thing you want to do is add further restriction with a smaller ID tube and filter. There have been plenty of arguments made against that; ignorant as they are imo.

.

OEM Mazda tube isn't 3.5in, which actually surprised me seeing as everyone uses these intakes without rescaling the MAF. To be fair on that same point, the Racing Beat intake I have on now is 3.5in and I haven't seen any crazy fuel correction. These are actually the same MAF, and I presume same base software as the Subaru ECUs, and there is nothing but issues if you change the MAF housing diameter and don't rescale it with those. My guess is that with the addition of possible positive manifold pressure on the Subaru, the range of the MAF is higher and thus resolution is much lower for the same use case. I have no idea, point is that it blows my mind no one seems to be rescaling these sensors.

There are benefits of having a smaller inlet to a larger outlet on an intake, but I can't speak to those specifically because that's not my area of expertise and I'd probably just be lying. So maybe it's worse, maybe it's better, either way I don't care because like I mentioned before I couldn't care less about power. As long as air is getting into the engine and the MAF is scaled properly, I am happy. If I wanted to make power, I wouldn't use an MSP engine. It's not worth cranking up to 11 compared to other engine options. I am just mimicking the AEM intake as much as possible for simplicity. I don't care about redefining the air intake for an engine that's already not moving a huge amount of air. I do understand going nuts on it when bound to a rulebook like in DSP, so I appreciate the commitment.

Oil Temp/Pressure and Water Temp Gauges

Okay, still work to do on this but it's mainly installed. I think I've posted a bit about these before so I'll just cut to the chase.

To be perfectly honest this level of integration is a bit overkill for a race car and I aboslutely could have just plopped some Defi gauges I have sitting on the shelf onto the dash and been perfectly happy with it.. but I wanted a bit of a challenge to both make something cool, but more importantly test my skills. Before I started this I had never design and created my own PCB before, and also struggled to make CAN hardware work (well) with software.

So first things first, I wanted a full integrated gauge screen inside the OEM cluster which looked like it came there from the factory. There was a lot of dead space under the fake oil pressure gauges so I figured it could use some population.

Cool, we have concept and an end goal. Now to get to that goal..

I designed a basic interface to both poll CAN data already on the bus (water temp) and then to look at CAN data from my own sensors. CAN data that was already available was simple, we just needed to reverse engineer the broadcasted CAN data and create an interface to receive it. Simple and easy. My own sensors were a bit more challenging, but at the end of the day we needed to put our own sensors on the bus, so we knew we could assume the end controller would just see it as a bus message. This allowed me to get going on some bench builds and development boards.

I decided to use an OLED screen simply because I needed the screen the blend in with the background of the cluster. And LED or LCD screen would have an awful backline sheen and that was just not acceptable. Lucky, Adafruit makes some pretty rad dev boards with a perfectly sized OLED screen for the job.

Next up was creating some interfaces to write arbitrary sensor data to the screen. Pain in my ass, because graphics are hard, but I came up with something like this. One thing to note is that you really only want to change the pixels that are actually changing otherwise you end up bad screen flashing, bad refresh rates, or your background getting blasted out by uncleared pixels. Display logic isn't really relevant to this forum I suppose, so tl;dr it was a pain in my ass but very much so worth it.


https://cimg2.ibsrv.net/gimg/www.rx8...71b6c4d31f.jpg

I also cruised around the interwebs looking for some fonts that matched the cluster's font style. I settled on this font and ported it over to the code. The font actually takes up the most memory -_-, but again I think it's worth it.

Cool, so we had a bench device and some basic software that worked... how to we get this thing into the cluster itself? Well.. we start BLASTIN! Also we pull up CAD.

Inside the cluster we can see a perfect spot once you trim away all of the garbage we don't need. In order to index and affix the screen properly, I needed a constant set of geometry that would always be the same no matter what. I found some through holes in the cluster PCB that did the trick well.


https://cimg7.ibsrv.net/gimg/www.rx8...750a663388.jpg

With this geometry we can then CAD up a mount with that pattern and then we will always have a constant place to pop our hardware into. To get that geometry right in CAD, I traced it on some paper, added a basic set of known dimensions and iterated about 3 times until I had a piece that popped right in like the last piece of a puzzle. From there is was just getting the rest height of the screen right, and a mount that held the screen tight. I think I did about 10 design revisions until I had it perfectly. Awesome. Now for the circuitry..

https://cimg0.ibsrv.net/gimg/www.rx8...3bb732594e.jpg
https://cimg3.ibsrv.net/gimg/www.rx8...353a05c0b9.jpg

I needed a daughter board that popped into the cluster and both drove the CAN receiving and the display. Went a bit ham, and created a full PCB (with bad circuit protection) to do both. I basically stole the design of my bench build and dev boards, thinned out the stuff I didn't need, and then aligned it on a board that would fit inside the cluster. I went with a pretty basic piggyback on an Atmel 328P with a SPI screen (from Aliexpress, hell yeah Chyyynaaaa) and SPI CAN MCU. Bit expensive by bulk productions standards, but it made my life simple.

https://cimg5.ibsrv.net/gimg/www.rx8...a7a0359f41.png

Generated the right files, emailed them over to a PCB manufacturer and in a few days I had this guy.
https://cimg6.ibsrv.net/gimg/www.rx8...ad6c2eef78.jpg

Populated the board with the components and BAM! As you may see there is a V2 rev in the silkscreen.. it's actually a V3 rev... tl;dr making your own stuff is hard.

https://cimg7.ibsrv.net/gimg/www.rx8...21a0e56b36.jpg

Alright. Cool. We had a board, and we had mechanical mounting for the screen. Mechanical mounting for the board inside the cluster was next. Again, bang out the CAD, find some reference geometry, print stuff until it works, and BANG


https://cimg0.ibsrv.net/gimg/www.rx8...76a69231ef.jpg

https://cimg3.ibsrv.net/gimg/www.rx8...d40db871ed.jpg


The cover pops on and everything is secured into the unit. You can plug it into the car as normal, and you're good to go. CAN ties in at the cluster, and power is with key on like the cluster as well. But as you may notice there needs to be a hole cut in the insert in a very specific spot... how do we do this.

Well, I had a plan to silkscreen my own inserts, ask a company to do it for me (spoiler: they wanted too much money) so either way I had to design and make dimensions for my own insert. I did this by scanning in the OEM insert and getting it vectorized. I made some basic cuts in the factory one and then used some electric tape to mask exactly where it needed to be with my screen in place. From there I applied those dimensions to the vector drawing and could now print out perfect templates to test as seen in the photo above.

https://cimg1.ibsrv.net/gimg/www.rx8...65a1e85a07.jpg

Like I mentioned, in a perfect world I would have these made or inserts properly cut (trust me, I almost bought a 40W laser cutter just for this project), but I needed to get this moving so I ended up just using the printed out insert as a template for cutting the factory insert in my other cluster.

Aaaaaaaaand look what we have!


https://cimg2.ibsrv.net/gimg/www.rx8...6d26663ac4.jpg

https://cimg9.ibsrv.net/gimg/www.rx8...0d04c1f6d1.jpg


This "end result" kind of leaves out the details of the two clusters I nuked in the process, as well as me swapping over my cluster's odometer to the new cluster by reprogramming the factory cluster EEPROM so there was full continuity. The car has no idea a completely new cluster is in it, and nor does anything else! Also, don't mind the wonky oil pressure.. the sensor isn't working properly in this picture... which leads me to sensors.

Sensors were actually done using the exact some board I made above, after all we just need something that can read sensor and broadcast CAN. That board can do it with a bit of an input change, and a complete software overhaul. I am working on another board revision to be able to handle everything better, but the tl;dr is that software with the same hardware is RAD. Basically I just did analog to CAN conversions (with some MEH filtering) and then broadcasted them out on my own new CAN message to the entire vehicle. My cluster then picks up that message and signals and parses them back into engineering units for display. Woo!


https://cimg4.ibsrv.net/gimg/www.rx8...82e724f235.jpg
https://cimg6.ibsrv.net/gimg/www.rx8...94b6061f4a.jpg


I'm pretty happy with both the performance, and style of everything. I think it matches great and the only thing left on the table is software to be able to change parameters (technically to literally anything you'd want) and/or units, as well as fixing the pressure sensor.

A bit more info on my sensors and a video can be found here: https://www.rx8club.com/rx-8-racing-...2/#post4919854 but this is my "official" post since it's finally installed in the cluster and working great.

sigh ... 3.5” OD is just the standard available that get’s you close to what really matters; the ID, which is what was also provided. edit; deleted improper comment spoken out of frustration.

pretty cool little gauge dash, but kinda small. probably hard to look at when you're doing 120 mph on the track. cool engineering exercise tho.

Yeah we will see! I am used to looking at 45mm gauges in a center pod, so hopefully this isn't any worse.

I forgot to add I did put some software in that the gauges will change to red as a warning if they exceed a threshold value. That should aid a bit in viewing too.

that would be good, have the entire screen blink red and the single valve that's over threshold fill the entire screen.

Whelp since this thread has devolved into "barely races, just plays with 1s and 0s" because I am just waiting on parts nowadays, I guess I'll post this here.

Was able to get the cluster on my bench to count up the odo, something I feel a lot of swap guys don't have. Kinda of complicated way the signal works, but hey, look at the numbers change!

more importantly, can the odometer roll back. asking for a friend. lol

Well, I tired to do some work on the car by adding a bumper and an intake... been set back because KBD stuff is actual garbage, and filters that fit are all on backorder because of COVID -_-

https://cimg9.ibsrv.net/gimg/www.rx8...0c8574d77b.jpg
https://cimg0.ibsrv.net/gimg/www.rx8...1af3fc4803.jpg
https://cimg2.ibsrv.net/gimg/www.rx8...b2aacc9559.jpg
https://cimg3.ibsrv.net/gimg/www.rx8...d767353f92.jpg

KBD Mazdaspeed rep was a floppy pile of trash. I expected just regular trash, but this wasn't even worth the time to make it work. Undertray was probably 2-3 inches out from even being able to bolt up, middle section was about an inch too wide, and the oil cooler openings were about as warped as a house in the California fires right now. They still even had a plate imprint on the outside of the bumper face.. like cmon...

Anyways, I was able to return it and I am still waiting for my refund to process. I had to call them to start the return process after I had received notification they received the bumper back over a week before I called. It's been 5 weeks since the return process was started. Pain in the ass, 2/10 would not recommend to a friend.

On the intake side of things, I did buy an AEM intake to clear up some room behind the radiator and got the 90 degree piece mounted up with some printed ABS parts. I went to buy an AEM filter and the clearance is just not there for it. I then specced out a smaller sized Green filter, but am still waiting on them to ship it after two weeks. They did say everything is delayed because of Covid so, fair enough. I did see some other guys using a K&N part number which I may just pick up and cancel the Green order if this goes on too long.. but for now I just have the AEM intake running the AEM filter in the intended AEM location since I have an event coming up and a filter would be a stupid reason to not have the car available.


https://cimg8.ibsrv.net/gimg/www.rx8...05da2c7fcb.jpg
https://cimg9.ibsrv.net/gimg/www.rx8...1678c71857.jpg