How to Calculate the Horsepower Loss at Altitude for Snowmobiles
Can I calculate the horsepower loss at altitude for my snowmobile?
Yes you can. If you’re headed to a higher altitude to ride your snowmobile, there are several variables to consider that are directly related to how your sled’s engine will perform in the thinner air. Let’s say you typically ride at 1,000 feet elevation but are headed to 6,000 feet-plus for a snowmobiling trip. Using the formula below, you can make a quick determination as to the approximate loss in horsepower that you will experience at the higher elevation:
HP Loss = (elevation x 0.03 x horsepower @ sea level)/1000
Now, let’s also assume you have a 150-horsepower snowmobile engine in your sled. The Horsepower Loss is going to be equal to 6000 times .03 times 150 divided by 1000 or a loss of 27 horsepower. That’s roughly an 18 % loss of power which is noticeable in both the feel and sound of your snowmobile’s powerplant. So, always take the time to test your sled’s performance before tackling big jumps or slope-side moguls to prevent coming up short.
If you’re headed up the mountain for a competitive snowcross or freestyle-snowmobile event, you will also need to consider the normal atmospheric conditions such as the relative humidity, ambient temperature and barometric pressure changes. Adjustments made to the carburetor or fuel injector can help offset some of the “Horsepower Loss at Altitude”. In addition, a local dealership may have a hot setup for adjusting your snowmobile’s intake and exhaust-port timing as well as a recommendation for the best octane rating for your racing fuel.
Don’t forget. If you’re looking for a hot tip, E3 snowmobile spark plugs are Born to Burn. Our snowmobile replacement plugs provide one of the strongest flame fronts of all high performance spark plugs on the market today. Check your local auto parts or discount store; or shop online at an authorized E3 dealer for your Arctic Cat, Polaris, Yamaha or Ski-Doo snowmobile plugs.