Until just a few weeks ago, the twin-engine cat class was divided into two naturally aspirated (not supercharged or turbocharged) engine categories—750 hp and 850 hp. Maximum compression ratio was 12:1 and maximum engine operating speed was 7,800 rpm. The engine displacement range was from 496 to 510 cubic inches.

J.D Byrider Skater 388

Like all catamarans in the Superboat class, the J.D Byrider Skater 388 will have reconfigured power for the Key West Worlds. Photo courtesy/copyright Tim Sharkey/Sharkey Images.

Thanks to changes recently adopted into the SBI rulebook, the Superboat class no longer has a horsepower limit. But that doesn’t mean competitors in the class will be going hog-wild with power. On the contrary, the new 9.5:1 compression ratio and 7,000-rpm operating limits for the still naturally aspirated engines likely will result in power output from 700 to 800 hp.

Why the change, especially so close to the season-ending Key West Worlds? Improved engine reliability and cost control for Superboat teams, according to Tony Marcantonio, the owner and driver of the J.D. Byrider 38-foot Skater catamaran that competes in the class. Marcantonio and others in the Superboat ranks, including Billy Mauff, created the new engine spec.

“We wanted to come up with an engine that would last for a year before it needed a rebuild,” said Marcantonio. “My guy rebuilds my engines for $12,000 each, so that’s $24,000 a year. I guarantee you, I’m the least wealthy guy running in this class, and I think that’s cheap.

“At 6,800 rpm, big-block engines are still pretty healthy,” he added. “Much above that, they start to break down.”

Marcantonio said he has spoken to five Superboat race teams that have made solid commitments to race in Key West with the new engine spec. At least three other potential Superboat teams are considering reconfiguring their engines to comply with the class, which means the event could have its first Superboat catamaran class in years.

With less power under the hatch, the boats in the class will be slower, something Marcantonio and others see as a plus in terms of safety.

“I don’t think you’ll see the 130-, 135-mph race speeds you saw from our class before, “ said Marcantonio. “I think you’ll see race speeds of around 120  and 125 mph. But that’s about right for some of these older cats with older canopies. So the change is about safety as well.”