Video Log Of The Restomodding Of My '76 RX-5 Cosmo (New Vid Jul 10/2024)
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 47: Electronic Instrument Cluster Conversion
The viewers have voted! At the end of part 46 I presented a choice as to what you would like to see next and by a wide margin, we have a winner. Episode 47 of my '76 Mazda Cosmo restoration focuses on converting the instrument cluster from 40 year old analog mechanical gauges to electronic gauges. Not some gaudy named-after-a-US-state Digital glowing green digital panel slapped into a classic looking frame of course. Instead, a true integration of the existing gauges with modern electronics and control, taking information from an MS3-Pro fed CAN bus. Suffice it to say, there is a lot of delicate detail here, working with ridiculously tiny screws, machining of small parts and some electronics as well. There will also definitely be a part 2 of this episode, and possibly a part 3, because building an OEM integration level instrument cluster is no small task!
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 48: Electronic Instrument Cluster Conversion - Part 2 - My 76 Mazda RX-5 Cosmo
Well it's that time again. Yes, time for another installment of my '76 Mazda Cosmo restoration. In part 48, I continue the process of converting the old mechanical instrument cluster to a well integrated modern unit while retaining most of the appearance of that crazy time we call the late 1970s. TFT screens replace rolling odometers, stepper motors replace gauge movements and useless faux gauges which were nothing more than warning lights get turned into something more useful. Lots of tiny milling, lots of tiny hardware and some delicate welding. This finishes up the mechanical work on the cluster. As I predicted, there is going to be a third installment in which I design all the electronics to make the thing work.
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 49 - Electronic Instrument Cluster Conversion - Part 3
It's been a long while, hasn't it? Who would have thought that retrofitting a 44 year old instrument cluster with modern electronics and building almost everything from scratch would be complicated? Yep, that's right. It's part 49 of my '76 Mazda Cosmo Restoration! And once again, I am continuing to work on the instrument cluster. This time I'm getting the final touches done by building the backlight boards, making the boards for the fuel and temp gauges, making some mistakes, and finishing up with all the cluster innards. It's another electronics episode mostly, which I know isn't my usual fare, however "electronics" is a big part of an electronic instrument cluster. And man, I'd have to say this is the most complicated single project I've done on this car so expect at least another episode to finish up the cluster.
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 50: Electronic Instrument Cluster Conversion - Part 4
Episode 50 of my '76 Mazda Cosmo Restoration is packed full of detail and information. Possibly more than any other episode released. Because after all, there's a lot to say about designing and building an Atmel 1284 powered CANbus communicating, stepper motor driving, TFT screen displaying, addressable LED controlling, rotary encoder twiddle accepting, heart of an electronic instrument cluster, circuit. That's what this episode primarily concentrates on with a bit more thrown in the middle. It's heavy on the electronics of course, and the last installment before final assembly of the instrument cluster. You might want to pour yourself a drink, sit back, brace yourself (that's what she said). By the way, I made an obvious mistake in this video. Can you spot it?
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 51: Electronic Instrument Cluster Conversion - Part 5
Episode 51 of my '76 Mazda Cosmo restoration is here! First, let's talk length. That's what she said. I know it's ridiculously long. The title of my sex tape. Thing is, this video contains the entirety of final assembly of the electronic instrument cluster and it was an ordeal. Stuff broke, mistakes were made, more stuff broke, and add a long wait for replacement parts.And then I had the joy of reliving it all while editing this monstrosity. I could have split it into two, but then that would extend the instrument cluster to 6 parts and I just wouldn't have it. So dear viewer, I implore you to have the same experience watching it as I had making it. But here's the thing: it worked out rather well and even though I have months of programming to make this cluster actually do anything more than twiddle the needles, I think it was worth it.
Schematics, code and board patterns from this video: https://www.aaroncake.net/76cosmo/cluster
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 52: Again With The Intercooler?! - Part 1 - My 76 Mazda RX-5 Cosmo Restoration
In any long running project, and no one will debate that this is a long running project, there are always things that one looks back on and reconsiders. And for years, there has been a big one in the engine bay: the intercooler. I was never happy with the angular placement and the almost improvised look of the plumbing. It seemed as though it was an after market kit made to fit a space. It was at odds with the engine bay. It ate at me. And after the instrument cluster I wanted to cut and weld! So I made the decision to seemingly go backwards and redo work already done. It was absolutely the correct decision.
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Unfortunately I have about 1/7th of the time in my life after buying the stupid house to work on the car, but rest assured the Cosmo will be completed.
Hell, maybe I'll even find time to show up at a meet this summer in the RX-7 (as worn out as it is starting to look).
Hell, maybe I'll even find time to show up at a meet this summer in the RX-7 (as worn out as it is starting to look).
Joined: Feb 2001
Posts: 3,999
Likes: 379
From: Aurora, Ontario, Canada
Unfortunately I have about 1/7th of the time in my life after buying the stupid house to work on the car, but rest assured the Cosmo will be completed.
Hell, maybe I'll even find time to show up at a meet this summer in the RX-7 (as worn out as it is starting to look).
Hell, maybe I'll even find time to show up at a meet this summer in the RX-7 (as worn out as it is starting to look).

we definitely have to see you out this season. It’s been too long.
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 53: Again With The Intercooler?! - Part 2 - My 76 Mazda RX-5 Cosmo Restoration
In part 53 of my '76 Mazda Cosmo restoration, I finish the rework of the water to air intercooler I started in episode 52. With the ideal position established, all the tubing needed to be changed to match. And if I was doing that, well, I figured I may as well ditch the pedestrian silicone couplers and clamps for something much more awesome. This is another episode filled with cutting, grinding and TIG welding. The final product is exactly how it should have been from the start!
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 54: Better HVAC Bracket and Improved *****
Time to tackle two more aspects of my previous work I am unhappy with. In part 54, I'm re-fabricating the bracket used to adapt the Vintage Air Compac Gen 2 HVAC unit (parts 29-31) and fixing an issue with the front camber I created when I used Mazda 626 ball joints to allow use of FC RX-7 spindles (parts 39 - 40). Years of looking at my poorly designed HVAC brackets weighed heavy on my conscience and I knew I could do better. So too with the front suspension; I had come to the conclusion that there wasn't enough adjustability to allow proper alignment. This episode, I correct both these mistakes to end up with results I find truly satisfying.
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 55: Air Suspension 1 - Rear Bags - My 76 Mazda RX-5 Cosmo Restoration
Episode 55 begins the project I've wanted to do since even before I bought the Cosmo: air suspension! In this video I modify the rear trailing arm to accept the air springs, create mounts to allow access to the bolts and fittings, then modify the frame rails with new spring perches. Lots of metal work and fabrication to get the rear end bagged. Enjoy!
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 56: Air Suspension 2 - Front Air Struts and Brackets
At long last, episode 56 of my '76 Mazda Cosmo Restoration is here! In this episode, I experience a rare phenomenon; a part that almost bolts on! Very few modifications are needed to fit the Air Dynamiks air struts, meant for a 2nd gen RX-7, into the Cosmo shock towers. Though I freely admit the way I went about those modifications was a little weird. Next up, I start on the brackets to mount all the support hardware in the trunk. Because an air suspension needs a compressor, tank and solenoids, right?
On a personal note, I know it has been a while. In January I ended up sick with COVID-19. It took me out for nearly a month and 6 months later, I am still constantly tired. So work on the Cosmo has been slow.
Patreon: https://www.patreon.com/aaroncake
Instagram: https://www.instagram.com/aaroncake_/
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 57: Air Suspension 3 - Compressor, Solenoids and Tank Brackets
Episode 57 of my '76 Mazda Cosmo Restoration picks up exactly where episode 56 ended: fabricating the brackets to mount all the air suspension support components. Here I complete fabrication of the tank, solenoid and compressor brackets. The idea was to create a compact and almost modular installation tucked into the inside of the rear quarter and I am happy with the result.
Thread Starter
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Part 58: Air Suspension 4 - Plumbing, Finishing and Demo
It has been a while, but finally it is time to finish the air suspension! And what does that mean? Plumbing, wiring, plumbing, and more plumbing. In episode 58 of my '76 Mazda Cosmo restoration, I wire up the compressor, pressure switch and control relay. Then I plumb the entire system including the compressor, tank, solenoids and the air springs themselves. A little fabrication is thrown in along the way, all leading to a reasonably satisfying payoff at the end. I know it has been a long wait since the last episode so let's make this one a long one and go until it's done!
Thread
Thread Starter
Forum
Replies
Last Post
Aaron Cake
Old School and Other Rotary
730
Jul 26, 2025 08:57 AM
Adaptronic Adpatronic Log ECU and log file
smikels
Adaptronic Engine Mgmt - AUS
21
Mar 28, 2017 03:24 PM







