We take the responsibility of educating people about our impellers very seriously. There are many variables in impellers and watercraft that you need to be aware of and knowledgeable about before you decide to purchase one. We want you to make an educated decision on which impeller is best for you and your watercraft, and by choosing Skat-Trak, you have made a step in the right direction. The following are some critical factors that we feel our customers should know.
Weight:
Each watercraft is unique in hull design and horsepower. Some watercraft are designed to carry 1 person, and others up to 3 people. With a varying amount of riders, weight being carried on some craft can fluctuate up to 500 pounds. The more weight being carried, the more bottom end you will need to get up on plane quicker. Another example of low end thrust needed would be pulling a water skier or knee boarder. The desired performance is usually more bottom end, which will be achieved by choosing 1 pitch combination lower than our general recommendation listed. We do not suggest choosing a pitch combination higher than our chart suggests for light weight riders.
Desired Performance:
When we design an impeller, our goal is to reach the absolute best overall performance and efficiency possible. Our charts suggest the ideal impeller recommended for the many different models of watercraft in stock, limited, and modified form. We want to give you both bottom-end and top speed without having to compromise, but for those people who still prefer one or the other, they would need to choose a pitch one lower or higher than recommended. Some of the pitch recommendations are targeted at people seeking top speed or acceleration.
Horsepower:
With the many different manufacturers and models of craft available today, there are also different size motors. A common assumption in this industry is, the more horsepower you have, the higher pitch impeller needed. That is not necessarily the case, when we design a performance impeller, we start from scratch. There are many factors to consider within the design of an impeller that determine the overall load and RPM the watercraft will have. The pitch of an impeller can be deceiving. Because of the many geometric differences in impeller designs, including our own, there is no correlation in pitch between various impeller models. They do not represent your craft's potential performance at acceleration and top speed, but is simply the pitch progression of the outer blade angle. For instance, comparing the stock impeller pitch to our performance design to gauge the aggressiveness of the impeller would be an inaccurate reference. We base our recommended pitch off each specific design that we find most efficient on each craft, with various horsepower ratings in mind. The relationship between the impeller and pump exit nozzle diameter is also critical to the performance of the watercraft. All our recommendations are based on each craft's stock nozzle diameter. We test and develop impellers for each make and each model of watercraft, one craft at a time, so you can have the best possible recommendation available to you.
Altitude:
Altitude can play a major role in watercraft performance. Considerable changes in elevation require a lower pitch selection, the lack of oxygen to your engine will not allow it to run at it's peak performance. If you are higher than 4500 feet above sea-level, we recommend that you choose 1 pitch combination lower than what our general recommendation chart lists. This will allow your engine's RPM's to come up quicker and higher than that of your stock impeller, or the normal recommended impeller. All of our impeller recommendations listed are based on sea-level testing.
