Tesla Model 3 Performance Swap: How It Works

• A YouTuber is attempting to transform a used Tesla Model 3 with rear-wheel drive into an all-wheel drive Performance.
• Rich Rebuilds, the original Tesla tinkerer, ordered the wrong battery for the base Model 3, so now he’s doubling up with the mods.
• The car got new motors, a new battery and new modules, but a simple software update is stalling the project.

The entry-level Tesla Model 3, which has rear-wheel drive, is the perfect car for a lot of people. It’s powerful enough for daily driving, and keeping it in tip-top shape isn’t really hard. 

Then, there’s the top-spec Performance, which has oodles of power and all-wheel drive. So, what can you do if you have an entry-level Model 3 RWD car, but stop thinking about that Performance model? The usual process would be to sell the current car and buy something that tickles your fancy.

Or, if you’re Rich Rebuilds, you get a load of parts off eBay and try to convert a rear-wheel drive EV into an all-wheel drive one. Rich, who’s the original Tesla tinkerer, discovered that his poverty-spec Model 3 had a high-voltage battery that was on its last legs.

So he bought a used replacement, only to discover that it won’t fit under the car because it was meant for a dual-motor car.

Instead of returning the battery and getting a proper replacement, he decided to do the exact opposite. And it works–sort of. After fitting new motors front and rear, the aforementioned battery, and a bunch of electronic modules, the car booted up, but it threw multiple errors.

Rich, who has plenty of experience dealing with janky Teslas, said that all the issues can be traced to the old software version of the donor vehicle, which hadn’t been updated since 2022. Because of this, several operations were unavailable in the Service Mode, including reflashing the firmware. Just a software reinstall was available, and it didn’t do the trick.

That leaves just one option on the table, and that’s to pay Tesla a subscription fee to gain access to its diagnostics software tool. This way, the software of the new modules can be reflashed and maybe, just maybe, make everything work as intended.