Vortech Superchargers are renowned for their drag racing and street and strip performance, and for nearly three decades, it’s been the quarter-mile and the local cruise nights where you’d most likely find their products providing the horsepower that enthusiasts demand. But a centrifugal supercharger is right at home in virtually any internal combustion application, and one of Vortech’s customers proved that in a big way by pressing not one, but four, of their blowers into the history books recently — on water.
Veteran offshore boat racer Don Onken’s ‘American Ethanol’ team pushed their 51-foot Mystic Powerboats catamaran to a new piston-powered record on their way to winning the annual Lake of the Ozarks Shootout — a top speed contest held in central Missouri in August. The Onken boat, with Slug Hefner at the wheel and John Cosker managing the throttles, carded a 217 mph lap down the river in front of tens of thousands of onlookers, taking the overall Top Gun title.
The ‘American Ethanol’ boat is motivated by four Keith Eickert-built, 582 cubic inch big-block powerplants fed by Vortech’s V-28 123 mm superchargers, producing an estimated 1,900 horsepower each, for a staggering total output of 7,700 horsepower. Onken, who has been participating at the Lake of the Ozarks Shootout off and on for nearly as long as Vortech has been in business, has seen his boat get progressively faster year-on-end, with a 186 mph terminal speed in 2013 and 188 mph in 2014, before the 14-71 roots superchargers were replaced by the Vortech V-23’s and high-octane ethanol fuel, increasing the power output of the engines by some 700 horsepower apiece.
Onken’s ‘American Ethanol’ boat won the Shootout a year ago, as well, topping 208 mph, which tied the previous mark for a piston-powered boat (the turbine-powered Spirit of Qatar owns the outright record at 244 mph).
“We are satisfied with making the boat perform like it should. And we are satisfied with sharing the record for a piston-powered boat with Dave Scott. He paid his dues over the years and brought so much attention to the Shootout. I have a lot of respect for Dave so it was nice to tie him.”
Despite setting the record by nine miles per hour, Onken isn’t waiting around for another team to snatch it away, as his team already has a quartet of 600 cubic inch powerplants in the works that he estimates will deliver a combined 9,600 horsepower — which would certainly mark the most extreme machine in the world with Vortech superchargers onboard.