@jdonalds , since you brought up the ECU I have been thinking about the high elevation problem. I am wondering if there is some king of chip / programmer available for these boats like there is for cars, trucks, and motorcycles. It seems to me that the computer could be 're mapped to get optimum performance at the elevations discussed above. I also wonder if a dealer could plug into the system and make air / fuel adjustments
This is a good thought, but the ECU is doing exactly what you want it to do, as
@OrangeTJ commented on. Back in my youth, an automobile would not run well in the mountains if it were a sea level vehicle, and you would have to tune it to the new climate/elevation. The great thing about an ECU, it is constantly measuring air density/pressure, and it compensates completely. And also as
@OrangeTJ said, the only compensation you can make is to squeeze more "air" into the formula, and the only way to do that is turbo or supercharging. Back to the ECU...all the kits/chips/tunes you see on ECU's do is adjust the fuel flow timing along with valves, and to adjust spark. These slight tweaks can change engine behavior for a desired effect. But you just can't get it to add in more air to the mix. Density altitude is just not something that most folks learn about. Sure, you know that things cook differently in the mountains than they do at sea level, taking longer, or needing higher heat to gain the same time to cook. When you learn to fly, you learn about effects of altitude, temperature, pressure, and humidity. And for the same reasons as a boat, car, or airplane isn't as powerful at higher altitudes, the thinner air and lower atmospheric pressure rob all of them of oxygen needed for combustion, and the atmospheric pressure to provide the oxygen molecules in a cubic foot of air that you have at sea level. Add to that high temperatures, and the number of o2 molecules decline in a cubic foot of air as the temperature rises. When I land in Denver or higher, the thin air under my wings and the sensors on the airplane take much more speed through the air to produce the same amount of lift needed to keep the airplane flying, and the engines require higher power settings to produce the same amount of thrust. That is why airplanes have service ceilings and have take off and landing altitude limitations. There is just simply not enough air to support the same operation at high altitude as there is at sea level. And back in the beginning of this thread, I mentioned some of this, as well as the fact that putting a speed impeller on the boat might grab a few more mph's, it will rob the low end out of the hole jump to get it. A guy that tows several tubes with larger riders won't like losing the towing power by adding a speed impeller and a guy that just cruises fast wouldn't like adding a power impeller...it is simply one or the other. And you mention optimum performance, that is what our engines/impellers are designed to do, but occasionally, someone will tweak them a tad to deliver the mix that is better suited to their desired sport. And that is fine, but it is a tradeoff, and it won't make up for thin air on a hot day.
