Danny Ledger over at the screamandfly.com site would know how fast the Powercat in the pic was. The 13s with twin 45hp Mercs and speedmasters would routinely run in the mid sixties (that's with only 90 horsepower total). The 15 in the pic has twin 80s which with speedmasters would probably be in the high 70s, or even low 80s, but that's just a guess. Jack Oxley, Danny Snead, and Bob Kies briefly ran twin Scott 75s on a 13, and those rigs were fast also.