Technical Tidbits: Tug of War Behind-the-Scenes
By: Bill Grannis
Last October on LakeSheen in central Florida, an Evinrude E-TEC 150hp and the new Mercury 4-stroke 150hp battled it out in a drag race, a top-speed run, and with a tug-of-war to see which engine was best in class. Over a three day period bass boats and center-consoles rigged with 150hp outboards and driven by experienced operators were put through their paces. At the same time everything was being filmed and photographed by a number of companies specializing in marine photography.
Bass boats were chosen for the drag race and top speed competitions as they are designed for getting up on plane quickly and running fast from one fishing hole to another. The watercraft of choice for a tug-of-war pointed to center-console fishing rigs with self-baling cockpits needing low-end torque to push through rough seas.
About 5 years ago, BRP Evinrude filmed a tug-of-war between their newly introduced 150hp E-TEC and the popular Yamaha F150 4-stroke outboard motor. The Evinrude easily pulled the Yamaha backwards which overturned the boat. The video caused a fire-storm on the internet boating forums that is still being rehashed after all these years. This article is about how the recent comparison tests were conducted and how the boats were set-up and operated according to their respective manufacturers.
I was fortunate enough to be invited to observe and document the testing procedures and to experience how an infomercial is filmed. With a camera around my neck and a notebook in my hand I nosed my way into the set-up area to record how the boats were rigged, tested, and inspected. BRP enlisted the services of a representative from a combination Evinrude and Mercury dealer to oversee the tests. This individual was familiar with both brands of motors and how they should be rigged and operated per each manufacture’s specifications.
The first day of testing and setup was for the bass boats used in the drag race shootout. A local Sheriff’s boat was on hand to keep things legal, inspect the boats, and to monitor the tests for everyone’s safety.
A Stratos 189 was the boat of choice and each hull was weighed to check that one vessel was not significantly heavier than the other. Measuring 18 feet 9 inches long with a 93.5″ beam and a 20″ transom the 1500 pound bassboats are rated for a maximum of 150 horsepower.
The new Mercury 4-stroke has a different length midsection and gearcase compared to the 150 Optimax. On water testing determined that it works best using the 3rd mounting hole whereas an Optimax 150 performs best in the 4th hole. Fastened in the 4th hole, the E-TEC 150 was actually a bit deeper in the water than the 150 Mercury when measured from the transom edge to the anti-ventilation plate.
Each rig was run to determine the best propeller for top speed, just as a good dealer would set up a boat for a performance oriented customer. Because each outboard had a slightly different gear ratio, the same size prop could not be used. A Mercury 23″ Tempest PLUS propeller was chosen as the 22″ version caused the motor to rev above the 5800 rpm limit. The Evinrude ended up with a 22″ Raker to keep the rpms within the same specification. Both drivers were similar in weight (keeping things as equal as possible) and are bass boat operators with many years of high-performance experience.
The film crews used several boats including a specially designed twin-engine rig with a movable boom and a gyroscopic mounted camera for vibration-free shooting. Most of the afternoon kept everyone moving and re-shooting scenes as the breeze would change direction or the sun would hide under a cloud. The drag race from a dead stop and the top speed contests were repeated many times and the results were always the same. Switching drivers would not change the outcome.
For the tug-of-war contest identical center-console SeaChaser models by Carolina Skiff were outfitted and tested with an Evinrude E-TEC and a 4-stroke Mercury 150. As with the bass boats, each was rigged per its respective engine manufacture’s recommendation and controls, gauges, and fuel systems. Water testing resulted in both motors mounted in the 2nd hole position and propellers were chosen to be the closest to the top recommended operating rpm for each motor. Any smaller pitch propeller for either outboard resulted in over-revving the engines. For the E-TEC a 17″ Rebel prop worked best and an 18″ Mercury Inertia did the trick for the F150 with its 1.92:1 gear ratio, slightly different than Evinrude’s 1.85:1 lower unit ratio. Both allowed the maximum rpm of each outboard without going over their respective red-line rpms and were propeller styles suited to the type of boat for maximum power and acceleration.
Again, for everyone’s safety the Sheriff’s boat remained on patrol plus a rescue diver was suited up and on-scene just in case something unplanned occurred. The boats were connected by a nylon tow strap and a “Y” harness. Throughout the afternoon countless tug-of-war contests kept the photo boats and film crews working constantly. The drivers varied the starting procedures such as allowing the Mercury to throttle up first to see if the results changed. They even experimented with the engine trim positions to different settings from fully tucked-in to vertical (neutral trim) with no change in the tug-of-war outcome.
As the sun started to set and the tired film crews put the cameras away, everyone was pleased with the comparison test results after three days of hard work. To view the 150hp comparison results, see your dealer for a copy of the DVD infomercial or go to www.Evinrude150Challenge.com.