Marine FAQ

What are the benefits of supercharging?

Supercharging, when done correctly, simply generates the largest, most cost-effective increase in power. Intercooled centrifugal superchargers in particular not only produce the largest power gains available with pump gas, they also generate more torque and horsepower per dollar than any other high performance option. Supercharging allows an engine to essentially produce the power of a much larger, highly modified engine when needed, with the fuel economy and drivability of a stock engine when the additional power is not needed.

How does supercharging increase performance?

Superchargers achieve performance gains by increasing the density of the air/fuel charge within the combustion chambers of an engine. This increase in density is achieved by forcing additional amounts of air (beyond the amount of air that normal atmospheric pressure would force into the engine) at the lowest temperature possible. Temperature is important because cooler air is more dense and therefore more powerful. Cool air also safely allows the use of factory ignition timing, while the presence of excess heat can cause detonation and requires the use of ignition retard (which can substantially reduce power). In more technical terms, supercharging increases both the volumetric efficiency of the engine and the mass air flow through the engine.

What are the major differences among supercharger systems?

The two biggest issues are the type of supercharger utilized in the system, and the design of the intercooler. Roots superchargers are the least efficient superchargers, which means that they consume the most power to turn the supercharger itself, and produce the most heat. Centrifugal superchargers are the most efficient, which means that they consume the least power and produce the coolest air. Intercooler design is also very important. If a system utilizes an extremely undersized intercooler with even a reasonably efficient supercharger, the system will produce excessive heat, limited power gains, and reduced engine longevity. With the advanced thermal design of ProCharger Marine intercoolers, not only is the heat rejection capability per cubic inch outstanding, the overall size and total heat rejection capabilities of these intercoolers is far superior to others.
For example, the ProCharger AW-324 intercooler core will remove far more heat than a competing intercooler core, which is utilized in the screw-type supercharger system for the 502 EFI. While the heat-rejection capability per cubic inch of these two intercooler cores is similar, the AW-324 features more than three times the cooling volume of the screw-type core, and is far more effective. Similarly, the ProCharger AW-504 intercooler, which is designed for even higher power levels than the AW-324, will remove even more heat. Air distribution with the ProCharger system design is also superior, as the screw-type core is positioned directly adjacent to the throttle body opening, which limits utilization of the core’s already limited effectiveness. Not surprisingly, the supercharger system which utilizes the most efficient supercharger and most effective intercooler will produce the largest power gains.

Why don’t all supercharger manufacturers utilize large intercoolers?

Lack of available space is the biggest issue which may limit the ability to effectively utilize intercooling. This is especially true for positive displacement superchargers, which have fewer mounting options than centrifugals. Due to their mounting locations, screw and roots blowers may be limited to an extremely small and ineffective intercooler, or even no intercooler at all. Similarly, space limitations inside an engine compartment may influence which intercooler a customer prefers, although intercoolers can typically be remote-mounted with a centrifugal supercharger, if necessary. Cost is also a factor, as intercoolers are not cheap. ATI is the largest manufacturer of aftermarket intercoolers for marine and automotive use, an advantage which helps ProCharger Marine offer the largest and most effective intercoolers, as well as the broadest overall selection.

Do I have to modify my swim deck or engine compartment?

Intercooled ProCharger systems are very compact, and typically require no modifications. Other superchargers may require modifications to the swim deck or elsewhere, and may not work with twin engine applications. For more information, please refer to dimensions provided in the back of the ProCharger Marine catalog.

Can I supercharge a 100% stock motor?

In practical terms, that depends on the type of supercharger. Virtually any supercharger could be installed on any motor, but if the reliable gain in power is very limited (older supercharger designs typically produce gains of around 15% on stock motors), then supercharging alone may not be economically viable, and engine modifications would be necessary to produce even a modest 25% power gain. Because Intercooled ProCharger systems produce such cool air and consume so little power, large increases in power are achieved with each pound of boost, and reliable power gains of 40-75% are typical on stock motors. Again, the issue is not whether stock motors can reliably be supercharged, it’s simply that some superchargers produce such excessive heat and limited power gains that it would not be worthwhile.

Do I need to change my propeller?

Changing your propeller allows you to achieve the desired increase in speed without changing your rev limiter. The increase in pitch size is directly related to the increase in power and speed, as well as your desired engine rpm. Please refer to the “Performance Profiles” for examples of actual applications which should help you judge the appropriate propping for the increased power level. Just as GPS and radar are more accurate than a speedometer, the ability to turn a large prop to the desired rpm is a good indication of actual power.

How will a supercharger affect my fuel economy?

An intercooled centrifugal supercharger increases engine efficiency. This in turn may actually increase fuel economy by allowing use of a larger prop, which in turn produces lower cruise rpm and fuel consumption.

What type of warranty is provided with ProCharger systems?

ProCharger Marine systems are backed by the best warranties in the industry. Virtually all ProCharger superchargers are available with an exclusive three year warranty. One year warranties are also offered for boost and power levels that others will not warranty for even one day. For information on the warranty coverage for a specific ProCharger system, please consult your catalog or price list.

How does supercharging affect engine longevity?

That depends on the design of the supercharger system, as well as the manner in which a boat is operated. In general, the two biggest threats to engine longevity are detonation and excessive engine rpm. Detonation may be caused by several factors, but the primary factor is usually excessive heat. Cool intake air (also referred to as charge air) temperatures are the single greatest protection against detonation and engine damage. In fact, every 1° reduction in charge air temperatures typically produces a 1° reduction in exhaust gas temperatures. Cool charge air also produces more power per pound of boost, which means that an engine will make more power with less rpm. This in turn allows the use of a larger prop, which will decrease not only the typical cruising rpm of the motor, but also the average lifetime engine rpm. Decreasing rpm obviously increases engine longevity. Some other supercharger systems, on the other hand, actually raise the factory rev limiter as a standard part of their system, largely as an attempt to compensate for lackluster power gains. Anyone can choose to raise an engine’s redline, and a supercharger manufacturer should not claim the added power that is gained simply by raising the rev limiter. In general, the supercharger system which produces the coolest charge air temperatures will deliver the greatest engine longevity. This is achieved by greatly reducing exposure to detonation, and allowing the vessel to attain higher speeds with less engine rpm.

Why do some companies modify ECMs and/or provide ECM piggyback modules?

Supercharging-related ECM modifications originated with a roots supercharger system. Because of the heat produced by roots technology, it is necessary to retard the ignition timing of stock fuel injected motors when utilizing a roots supercharger. Power gains with a roots supercharger are limited to begin with, and fell to around 15% with the power-robbing effects of ignition retard. To address the opposing needs for ignition retard and more power, the ECM was modified to not only retard timing, but to also raise the rev limiter - and allow a higher power claim at the elevated redline. Others have since followed, and while manufacturers try to position their ECM modifications as a good thing, the fact is that any need to retard ignition timing is actually an indication of excessive heat. The same can be said for any supercharger system that requires EGT warning lights. As for ECM piggyback modules, although these were originally designed to also retard ignition timing without being forced to modify the ECM, this approach did not work well, and they are now used almost exclusively to control auxiliary fuel injectors. Please note that such piggyback modules are controlling additional injectors installed at the throttle body, with an intake manifold that is not tuned for the introduction of fuel at this point, creating the potential for uneven fuel distribution. Because Intercooled ProCharger systems increase fuel delivery by utilizing the the highest rated fuel systems of any supercharger manufacturer, additional fuel injectors and piggyback modules are not necessary.

Do ProChargers work better on stock or modified engines?

Intercooled ProCharger systems provide cool, engine-friendly power, and work extremely well on both stock and modified engines. Because Intercooled ProCharger systems provide the coolest charge air and largest reliable power gains, this means that substantial increases in horsepower and performance can be reliably achieved without modifying your motor; modifications would simply produce even larger gains. Intercooled ProCharger technology also allows you to return the motor to stock form if you decide to move the supercharger system to another boat. This approach can be contrasted with roots blower applications, in which engine modifications are basically mandatory due to excessive heat from the supercharger, and low % increases in power from the supercharger alone. Intercooled ProCharger systems also provide advantages if you choose to increase your power levels in the future. ProChargers provide a broader flow range than other superchargers, making it easier to increase the power level through increased boost and/or engine modifications, with far less chance of “outgrowing” the supercharger.
For modified and highly modified applications, no other supercharger can approach the combination of durability, efficiency, and total airflow that completion ProCharger models offer. The largest ProCharger model now supports over 1,800 marine horsepower, and is available with a one year warranty. And unlike the “one size fits all” approach utilized by some companies, ProCharger Marine has the broadest offering of superchargers and intercoolers available, ensuring that both your supercharger and intercooler are properly sized for optimal performance with your power level. Stock or modified, we have you covered.

Do I need two superchargers?

Only if you have two engines. With an Intercooled ProCharger system, one supercharger alone will provide more power than some other companies can provide with two, and will also be far more cost effective. With current supercharger technology, the use of two superchargers on one engine typically indicates a lack of durability (the supercharger must be spun very slowly to avoid breakage) and/or a lack of efficiency at maximum airflow. Warranty policy is also a good indicator of a supercharger’s durability.

Who manufactures ProCharger superchargers?

Accessible Technologies, Inc, designs and manufactures ProCharger marine, automotive and industrial superchargers, intercoolers and complete systems. ProChargers (and most centrifugal and roots superchargers) are designed and manufactured in the USA, while screw-type superchargers are imported. Being a manufacturer rather than an importer and/or reseller is important, because manufacturers are able to design supercharger models specifically for individual marine applications, while importers do not control supercharger design, and are limited to the models offered by the foreign manufacturer.

What causes the transoms of some boats to be discolored?

A discolored transom is indicative of a rich air/fuel ratio. Some OEM applications, such as the 502 EFI, tend to run rich from the factory, and more discoloration may occur with the addition of a supercharger (due primarily to increased exhaust output). ProCharger systems utilize a boost-sensitive fuel pressure regulator, which allows adjustment in the field to address either a rich or lean air/fuel ratio, as opposed to ECM modules which need to be removed and re-flashed. Generally, the bigger concern is not a rich air/fuel ratio, but rather a lean air/fuel ratio, which typically results from utilizing exhaust or engine modifications without adjusting a supercharger system’s
preset fuel delivery. Additionally, based on aerodynamics, not all hulls are subject to discoloration. For those that are, high sheen polymers or waxes may diminish or eliminate discoloration, as well as simplifying general cleaning.

What fuel octane is required?

The use of 91 octane fuel is generally required for use with all modern supercharger systems, regardless of brand. However, the fact that ProCharger Marine systems produce the coolest air temperatures means that some ProCharger applications will be safe with 89 octane fuel. In particular, an M-3 or M-3SC ProCharger with an AW-504 intercooler is a great combination for customers who do not have access to 91 octane fuel and will be running low boost levels. Please refer to the back of the price list for more information.

Do I have to punch a hole in the oil pan for the supercharger oil supply?

No. SC ProCharger models, featuring self-contained lubrication, are available and have eliminated the need to tap into the engine oil system (which may require engine removal). These SC models are the only self-contained superchargers available with a three year warranty. ATI also offers its original oil-fed models as well.

Why should I choose a ProCharger system?

ProCharger Marine systems are the best available because ATI’s overall combination of technology, experience and service exceeds all other companies by a substantial margin. Rather than generic, meaningless claims, we can demonstrate specifically why ProCharger Marine superchargers, intercoolers and complete systems are better than others. Check the facts. Regardless of engine type, Intercooled ProCharger systems are the undisputed leaders for maximum reliable power gains and warranty coverage. ATI has devoted more engineering resources to the development of marine supercharger systems than any other company, and ATI’s commitment to innovation and quality is unmatched. ATI’s service staff is also the largest and most knowledgeable in marine supercharging, and ProCharger Marine systems have thousands more hours of actual in-water testing and usage than any other company.