Tesla CEO Elon Musk announced that a “Tesla/SpaceX Hyperloop pusher pod” has bolted down SpaceX’s Hyperloop test track at 355 km/h (220 mph), shattering the previously held Hyperloop pod top speed record of 202 mph set over the weekend.

Musk said in an Instagram post that the Tesla pod could soon reach a top speed of 500 km/h — or half the speed of sound — after “a few tweaks.”

The Tesla/SpaceX Hyperloop pusher pod is used to help propel student Hyperloop pods for SpaceX’s Hyperloop competition. Some of the pods don’t have electric motors used for acceleration, so the pusher pod is used to propel the student pods down the vacuum tube as part of the competition.

As described by Musk, the pusher pod is almost like a tug boat.

“We took the SpaceX/Tesla Hyperloop pusher pod for a spin by itself a few days ago to see what it could do when not pushing student pods,” wrote Musk on Instagram. It’s “kind of like racing with a tugboat.”

Tesla has held two Hyperloop competitions this year with the recent winner, WARR Hyperloop, reaching a top speed of 325 km/h (202 mph).

WARR Hyperloop, an academic Hyperloop group, set the record over the weekend, besting Hyperloop One’s 190 mph record set earlier this year. Musk was reported saying that the WARR team had the best design of the competition, and the thrilling test runs and Musk statements can be viewed in WARR Hyperloop’s livestream.

Posted by WARR Hyperloop on Sunday, August 27, 2017

The test run comes as both Musk and The Boring Company have been rumored to be joining the race to develop the best Hyperloop technology. The Boring Company announced in early August that its tunnels would be used for Hyperloop technology just days after Musk hinted that he wanted to build the Hyperloop project between New York City and Washington, D.C.

In the past, Musk has largely remained on the sidelines of Hyperloop development while companies like Hyperloop One and Hyperloop Transportation Technologies work to make his vacuum sled skate transportation technology a reality.

The SpaceX Hyperloop competition was established for academic groups to test their technology, further encouraging development and trials of the technology that could change transportation around the world.