CoilShift

Something great is coming.
Your Tesla is going to love it.

[Maciej P. Wilczyński @maciej]

They said I couldn’t run custom apps in a Tesla.

I proved them wrong. I can, and I will. And no, it’s not going to be a click counter 😈

Want to install third-party apps in yours too? Something big is coming.

@CoilShift

[Maciej P. Wilczyński @maciej]

This is the world’s first and only* legacy Tesla Model 3 retrofitted with FSD Hardware 4. It also happens to be my car!

The story begins a few months ago, when – inspired by @mikegapinski’s efforts to launch FSD in Europe – I’ve started digging around my Tesla’s infotainment and related systems, their security, and reverse engineering of all the firmware artifacts I could get my hands on. At that point I still had no idea how deep into this rabbit hole I was eventually going to wander and how many hours of sleep it was going to take away from me.

This was my first hands-on experience with FSD and, albeit still awfully impressive, v12 on HW3 was not the chauffeur experience I was hoping for. I knew Tesla wasn’t going to offer an official retrofit option, ever, and starving for a new adventure, I slowly started looking around Tesla’s official car schematics, comparing different variants of HW4 computers and mapping signals between HW3 and HW4 connectors. It quickly became clear that it was not going to be a weekend project. Not really enthusiastic about the odds, I shifted my focus onto other areas of the car—mainly the MCU itself, deep RE of both the hardware and the software, and learning as much about its internals as I only could.

Two months pass by, I’m leaving on vacation with my wife and kids. Destination: LA. Rental car: FSD-subscribed Tesla Model Y, Juniper. Of course. I knew it was going to impress me. I did not know it was going to blow my mind. And sure as hell I did not expect it to impress my wife too (which is not an easy task for anyone or anything, trust me on that).

During our wonderful two weeks there we’ve done about 2k miles in the Tesla. Out of those, I don’t think we’ve driven more than 30 miles ourselves, combined. All the rest, including a trip to Vegas and back through the Death Valley, was FSD v14—with not a single disengagement, even in rough conditions and poor visibility.

Back home, it became clear to me. I’m either buying a new car or retrofitting HW4 into my Model 3 so that I could experience real FSD at all times. If you’re reading this, you know which path I took.

Want to learn more about the retrofit process and how it all came together, what issues I experienced along the way, and how I managed to make it (nearly) all work? Drop me a follow, I’ll be sharing much more details in the coming days and weeks. And, spoiler alert, that retrofit is just the beginning 😈

* - that I’m aware of — but I don’t think anyone else in the world is mad enough to have tried that