The Top 10 Ways to Increase Speed and Handling

Photo- Performance Boat Center

There is one thing that all boats seem to have in common. They are never quite enough.

Boat owners everywhere want more space, or speed or comfort, or all three. Unfortunately, budget realities usually prevail, so most of us only dream of bigger, better, and faster. Your boat won’t give you the space and comfort if a three million dollar yacht, but you might be surprised how far a few simple tips can go in helping you get more speed and better handling from your existing boat. Lets take a look at my “Top Ten” ways to improve your boats performance.

# 10 Steer Straight

We should remember that the shortest distance between two points is a straight line and water provides more straight line opportunities than roads. At any specific time and location, water conditions will be the same, so it will be having the best steering system in your boat that will deliver a straight line advantage. You should be able to steer your boat in exactly the direction you want in most water conditions. Hydraulic steering systems are the system of choice, and there are several to choose from. They use hydraulic cylinders with fluid pressure to accurately turn the outboard or rudder. Select a system that uses two cylinders for optimum control. Hydraulic systems are almost always used on horsepower ratings of 150 and over. You will know if your current steering is not working well if your boat is difficult to handle and you fund yourself wrestling with the wheel. In which case, replacement is recommended.

# 9 Active Aerodynamics

It’s easy to overlook the things that extend from your boat into the air and create aerodynamic drag. For example, have you ever noticed the external items on many ski boats? According to Rob Watson Racing, "If you have a ski boat that runs 50 mph when clean, and you add the typical antennae, tow arch, wake board holders, and large speakers, you could reduce your top speed by as much as 6 mph." Aside from necessary electronic parts, you should minimize the number of things that you ask your boat to push through the air, in order to minimize ‘parasitic drag’. Classic examples of such items are fenders left hanging outside the boat to drag in air and water, flags flapping at all speeds, and appendages such as speakers, rod holders, and external grab rails. Conversely, a smooth laminar flow deck can actually add to performance by creating topside lift. Using aerodynamic lift effectively reduces drag by reducing the boat’s wetted surface. You can also improve the laminar flow on your boat by replacing fixed deck lights and cleats with pop-up equivalents, available from quality hardware manufacturers such as Accon Marine.

# 8 Performance Parts

There is no shortage of aftermarket parts that will increase the power of your boat engine. Such performance parts can usually be simply bolted on. Everything from superchargers to billet battery boxes can be found on dozens of marine accessory websites. Their effect on performance increase will vary, therefore budget carefully so that you don’t spend more than the cost of a new motor. Try to purchase only what is simple to install and will provide a proven benefit without voiding the warranty.

True performance buffs will are replace cam and lifters, molly rings, alloy push-rods, seamless cam bearings, and over-sized pistons. Some outboard motors are mechanically identical to a higher horsepower version. For these motors, you can look into installing an ECU Reflash. This is a replacement chip that will significantly modify engine settings and increase horsepower. Be aware that there is generally a trade off when you go to a chip solution, because installing them usually results in a shorter engine life and/or a voided warranty. A less effective electronic upgrade would be to install a modified plug-in module. Surprisingly, it does not take much labor to implement these electronic upgrades, yet costs vary dramatically with work performed, the quality of parts purchased, and the ability of the engine mechanic.

# 7 Happy Hydrodynamics

Water friction on a boat hull creates large amounts of drag. As we know, this drag creates speed loss and fuel inefficiency. Step one in combating this effect is to keep your bottom clean. Special waxes can make your boat hull more slippery and inhibit the growth of microorganisms that try to make a home on the hull of your boat. And don’t forget to do the same with your lower unit.

When driving, remember that every boat was designed to operate at a specific attitude, or angle of attack, to maximize lift and minimize hydrodynamic drag. Be sure to operate your boat at the optimum trim angle for each speed level to match your boats design specifications. Once on plane, raise your trim gradually, from full down to the point where you can feel the boat slightly loosen its grip on the surface of the water. If you have tabs, run a straight edge under the boat and mark on your tab gauge exactly at what position the tabs are flush with the boat bottom. Run them in that position except to compensate for ‘listing’ or when you are coming onto plane. Failure to do this will reduce your running speed, just like flaps do on an airplane.

Remember that the less boat in the water, the less hydrodynamic drag and the better your boat will perform. Just don’t sacrifice control.

# 6 Dynamic Drives

It’s hard to imagine the amount of drag produced by the apparatus that hangs down below the bottom of your boat. Whether it’s a shaft and struts, or the lower unit of an outboard or sterndrive, you can be sure it is slowing you down. Recognizing this is another key in determining ways to improve your boat’s performance.

Boat engineers specify in their designs exactly at what height the propeller should be located. This is called the “X-Dimension." This height is calculated to deliver normal boater operations. People wanting higher top speeds will accomplish this by raising the X dimension slightly (this is generally done at the expense of some pulling power). With part of the propeller turning closer to the water surface, some air is pulled into the blades, reducing propeller load, which in turn allows the prop to more easily spin up to higher RPMs, which in turn allows you to use a higher pitch prop, which in turn increases top speed. Note that this procedure does include the purchase of a higher pitched propeller and/or a different style propeller.

Boaters with outboards can raise their X dimension very easily by raising the whole motor on the transom. To find your optimum height for high speed, raise your outboard about one half inch at a time, being careful not to over-rev the engine. Loosen – lift ½ inch – tighten – test – repeat. If you want both acceleration and top speed, consider a hydraulic “jack-plate." This accessory will allow you to trim the entire motor up and down, as well as the standard trimming in and out. Jack plates, which cost about $1,000, can greatly increase your top speed, but they do require your full attention when driving.

Boaters who own cruisers operating with shafts and struts have limited ability to reduce drag. But recent developments in pod drive systems, such as Volvo’s IPS and Mercury’s Zeus, have forever changed the way future yachts will be built. These systems not only achieve a more efficient thrust, but with the use of a small joystick, they allow you to maneuver 360 degrees and move sideways to parallel park, eliminating forever the fear of crashing into a dock. Boaters who want to retrofit to a joystick maneuvering system, (JMS), to their boat, can now do so.

# 5 Better Breathing

All reciprocating engines like to inhale plenty of air and they also like to have it exhaust freely. An aftermarket exhaust system is one of the most popular performance accessories and delivers a big bang for the buck – literally.

High temperatures also reduce engine efficiency, so if your engine is inside the boat, ensure that the air vents are large enough to allow plenty of cooler outside air into the engine compartment. A polished steel manifold and riser kit is an affordable alternative to stock cast iron manifolds and you can order a pair for about $1,600 from companies like IMCO Marine.

I would like to note here, that a performance exhaust system does no longer synonymous with a loud boat. The latest technologies give you free flow exhaust with very low decibel levels. Mercury Marine uses sound canceling technology to offer performance systems without the noise. NorTech, Donzi, Cigarette and others offer low sound level systems, by feeding some of the exhaust into the propeller blades.

# 4 Re-Power

Sometimes the best way to find the performance you want is to bite the bullet and install a completely new engine with higher horsepower. This is easier to do than you might think. Outboard motors, for example, can be simply lifted off and a larger engine bolted on. You must be careful not to exceed the horsepower rating printed on your boat’s “Capacity Plate," but most outboard manufacturers have special departments that will help guide you with your re-power specifications and installation. All original equipment motor builders offer their own re-power programs. Begin your search by contacting established companies directly for engine recommendations, information, and pricing. And there is an added benefit here: engine replacement also gives you the advantage of a brand new engine warranty.

# 3 Lighten the Load

Between adding accessories and leaving more items on the boat, all boats get heavier with age. Performance boats are built to weigh as little as possible. There is no easier way to improve your boats performance than periodically going through your boat and removing all non-essential items. The pounds add up in a hurry and you will be pleasantly surprised to see performance improve with every few pounds you remove.

For short trips, leave your anchor at home and even when you carry one, you don’t need to have the entire anchor rode made from heavy link chain. Another way to reduce weight is to keep your onboard tanks, (water, fuel, bait) filled only to a level that you require in the short term. An extra 25 gallons of gas is the equivalent of having another adult passenger.

When you are down to the essentials, ensure that your remaining boat weight is distributed properly. Periodically, review what you have on your boat and determine if you have added weight or done anything to modify your boats center of gravity. I know a 30’ cruiser owner who added a large swim platform so he could carry a dingy, then was surprised that his boat could not get onto plane.

# 2 Performance Propeller

Never underestimate the importance of that final gear in your drive system -- the propeller. Check your prop for wear and damage. Even the slighted nick in the leading edge of a prop will seriously impede performance and your prop should be repaired or replaced immediately.

Upgrading your prop may take a little patience to find the best replacement, but is one of the least expensive performance improvements you can make. First, choose the prop material, based on where you plan to boat. If you plan to boat in rocky uncharted waters, you may want to choose an aluminum prop or composite replaceable blades like Piranha. But if you can swing them, stainless props are your best choice when it comes to performance. This is because stainless is stronger than alternative materials and therefore can be made thinner to slice cleanly through water.

Most props today are three bladed. It is a nice compromise between five and one. A four bladed prop is like having wider tires on your vehicle for better traction (or if you have enormous amounts of horsepower that you need to transfer to the water). So if you have a heavy boat, a four blade will give you more grip and help you come onto plane faster. Pitch is the number of inches that a propeller theoretically moves forward with every revolution. The higher the horsepower of your engine the higher the pitch, or load that you can place on your prop and expect it to convert into speed. You should select a pitch number that will allow your engine to turn up to the manufacturer’s maximum recommended RPM level. Start with a propeller that allows your engine to reach, but not exceed, the red line on your tachometer, then try one or two different prop sizes to determine the optimum pitch for your boat.

Of course there are style considerations, such as raked blades, cleavers, and blade area. That leads me to suggest that once you reach this point in your prop testing you contact the help desk of a specialty propeller manufacturer that is within a general boater’s budget, such as PowerTech Propellers. These prop pros will take the information you have gathered, ask you a few questions then recommend from hundreds of sizes and styles, a specific prop that will best do the job for you.

# 1 Captain Correctly

The absolute number one way to increase the performance of your boat is to ensure that you are driving it correctly. Practice until you are familiar with the controls on your boat and are comfortable driving in all situations. Keep your left hand on the wheel at the 10 o’clock position and your right hand on throttle (professional offshore drivers even bring along an extra person to handle the throttles separately). Steer and throttle gently, not in jerks or sharp turns. Your RPM gauge can be more beneficial than your speedometer. Be sure your gauges are accurate and easy to read, such as the monster gauges manufactured by Livorsi Marine.

There is no point in having a fast boat if you cannot operate it to full potential. Consider polishing your driving skills by taking pointers from professionals. Boaters are always surprised at how much they learn and how much safer they feel after taking a professional driving course.

I hope you put some of these ideas to good use and have a great boating season. #tips