Better Performance Without Adding Power: 2 Hot Tips
The first V-bottom broke 100 mph in 1981. But consider this: The boat that did it was a 30-foot Velocity with twin 500-hp MerCruiser engines, whereas just last month a 29-foot-long Outerlimits V-bottom with one 565-hp Mercury Racing engine reached 99 mph at the Lake of the Ozarks Shootout. (See Mercury Racing 565-Powered 29-Footer Hits 99 mph.)
The gains in high-performance hull design and efficiency in the past 30 years are undeniable, as are the advances in construction technology. The conventional hull, vinylester-and-resin-pad-bottom Velocity probably weighed 2,000 pounds more than the stepped-hull, epoxy-and-carbon-fiber Outerlimits—the extra engine and drive alone accounted for a significant chunk of that. Why else would it take 500 more horsepower for a boat of roughly the same length to run roughly the same speed? Obviously, lower weight plus greater hull efficiency equals more speed on less power.
Still, power means a lot when it comes to going fast on the water. In fact, there’s really no substitute for it. But as anyone who’s gone shopping for it lately can tell you, new power is expensive. Rebuilt and refreshed bigger-horsepower engines than those currently in your boat can save you some money over going new, but they’re still pretty expensive. Another popular power-upgrade route is beefing up your existing out-of-warranty engines with a supercharger kit, but in addition to the cost of the kit—likely in the $10,000 range—you’re going to have to beef up your drive to handle the new power.
So what can you do to eke a few more miles per hour out of your go-fast boat? Here are two smart ways to go—without touching your engine.
Lab-finish your propellers
CNC machine finishing has taken today’s four-, five and –six-blade high-performance propellers to outstanding performance levels right out of the box. But there is still more performance to be had. That’s where Mercury Racing comes in. For about $1,000, they will take your stock propeller and, based on your performance objectives (more top end, better acceleration, etc.) tune it to meet those objectives. Tuning—”lab-finishing” in the parlance of the company that invented the term as it relates to propellers—can mean thinning propeller blades, lessening and increasing cup, and a whole bunch of other stuff the folks at the Fond du Lac, Wis., company prefer to keep to themselves. Generally speaking, it enables go-fast boat owners to go up a size in pitch (the theoretical distance inches a propeller moves a boat forward with each rotation) and that can translate to an increase in speed.
Blueprint your hull and drive
Your hull is only as true as its original design, the condition of its mold, and skills of the people who build it. For that reason, a lot of builders and high performance go-fast boat shops, such as Sunsation Performance Boats in Algonac, Mich., and Bandit Performance Marine in Brick, N.J., offer what they call hull blueprinting. For a price — anything from $5,000 to $10,000 is standard — the builder will go through the hull with leveling tools and a grinder and take out any hooks, waves, or other imperfections. While go-fast boat owners generally submit their rides for hull blueprinting to cure some handling ill, the process frequently results in better overall performance, including better acceleration and a bit more top end.
Now, think about the lower unit on your drive. Sure, it looks hydrodynamic, but water molecules are sticky little buggers, and drag is the enemy of speed. For about $5,000, Wilson Custom Marine in Stuart, Fla., will blueprint your drive’s lower unit—approximately $10,000 for a twin-engine boat. That means, once again with power grinders and sanders, they will thin and shape the drive, refining it it for maximum hydrodynamic efficiency. Wilson is the only outfit in the country that offers this service.
Of course, if you want to go even faster you can always add horsepower, and we wouldn’t try to talk you out of it. Just be prepared to open your wallet.