Buckfield-based duo Fritz Grobe and Stephen Voltz plan to shut down a portion of Manhattan’s West 53rd Street on Tuesday to make room for their own invention: a soda-and-candy-powered rocket car.

The guys, known as Eepybird, are scheduled to appear Tuesday night on the “The Late Show with David Letterman.”

“It’s going fantastic,” Grobe said Monday morning from his home in Buckfield. He, Voltz and a crew of four friends were preparing for the trip south with the rocket car and a 17-foot-long U-Haul, filled with assorted gear, including 108 custom-built pistons, Mentos candies and 120 cement blocks.

“We’re still overwhelmed to see how viral video works,” Grobe said. “We performed for Letterman almost four years ago to the day.”

Since June 1, when Eepybird debuted the rocket car on the Internet, the video directed by “The Fast and the Furious” auteur Rob Cohen has been seen more than four million times. However, it’s still way behind the 50 million who watched the guys’ first experiments, creating fizzy, Vegas-style fountains by dropping Mentos into 2-liter bottles of Diet Coke.

That video sent the guys on their first round of national TV appearances, which also included “The Ellen DeGeneres Show” and “The Tonight Show.” It spawned live appearances as far away as Japan and Turkey and even a new category of world records, measuring the number of Diet Coke and Mentos geysers released at one place and time.

Next week, the guys plan to travel to Germany to reclaim the record, firing off 2,400 geysers.

First, they must make it through New York City. The show will mark their first public rocket car performance. The second will come only hours later, when they are scheduled to perform on “The Early Show” on CBS.

There, too, they will have to block a portion of a midtown Manhattan street, nearer to Central Park.

To get permission to perform on the streets, the guys had to promise New York City officials they would not break the speed limit.

That was not a problem for the homegrown technology created by Voltz and Grobe.

The car — a combination girl’s bicycle and utility trailer — is powered by the duos’ specially designed piston drive, which harnesses the geysers and propels the car from a concrete-reinforced blast wall.

In the Internet video, it blasted for 221 feet on a flat surface.

For Letterman, they’ll run the fizzy car on West 53rd Street, which runs beside Letterman’s Broadway theater.

“It’ll be surreal,” Grobe said. They’ll perform in the same spot they did the last time, behind barricades and uniformed New York City police officers. “The next day we stood there watching the cars go by and said, ‘Did we really do that here?’”

Eventually, the guys plan to bring the rocket car back to Maine for a performance.

“It’s too much fun not to share it with people at home,” Grobe said.

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