Jason Hughes, wk057 on TMC and Twitter, is a celebrated Tesla hacker known for his highly-modified Model S. The car started as a P85, but Hughes upgraded to a larger battery pack and dubbed the car a “P90++”.

Now, after upgrading the battery again, he’s calling the car the “first and only RWD Tesla with a 100 kWh pack.” Or, “P100++”.

Hughes gave a few details about the battery swap on TMC:

It required the replacement top-ring piece for the high voltage connector. It also requires some software changes and the hardware the module I built for the Pxx++ modification which, among other things, emulates a non-existant front drive unit to convince the car that it is dual motor. It would be nothing for Tesla to actually produce firmware that works with the 100 pack in RWD cars, though, without any software or hardware mods…. but I don’t see them doing it.

Hughes said on Twitter that he expects the pack to offer 320 miles of range.

Charged to 316 rated miles last night. Didn't have enough time to wait for that last bit of top-off charge before I had to head out. Should be 320 rated miles at a full 100% charge. First RWD Tesla with a 100 kWh pack. #RoadTripTime @HSRMotors pic.twitter.com/IRunB0Be2Z — Jason Hughes (@wk057) January 12, 2018

Hughes’ Model S is an early model with only a single motor, not meeting the dual motor requirements to run Tesla’s Ludicrous mode, which is capable of zero to 60 in 2.5 seconds. With a need for speed, Hughes engineered a hardware and software system to enable Ludicrous on the single motor car. The system offered a 30 percent bump in power, producing an estimated 575 horsepower at the rear wheels. You may also remember that Hughes was able to successfully retrofit Autopilot onto the pre-Autopilot hardware P85.

Read more about the car and Hughes’ projects here.