The SHOT starting system is unique to the Powersports world -- a starter that answers a mountain snowmobiler’s need for easy starting without adding significant weight.
Conserving energy in high altitude exertion is paramount, so adding weight to a vehicle is avoided, but rope starting a snowmobile 30-40 times a day also requires significant energy. SHOT solves this tradeoff of a lightweight, easy to maneuver snowmobile and ease of starting, by eliminating the battery, starter motor, solenoid, ring gear and cables to give push button starts. Now the rider saves energy for riding – not pulling a rope.
The concept began with the dream of eliminating the battery, starter, ring gear and associated hardware by using a direct starting method. The advantages of E-TEC direct injection provided some possibilities to fire the engine using a stratified charge without compression, and the large generator acting as a motor could provide some momentum to help spin the crankshaft to begin the combustion process. The current state of lightweight capacitor technology was the final piece needed to make the system a reality.
This combination of technologies also required a large amount of software and electrical energy management work that combined teams from the United States, Canada and Austria to bring to the concept to market.
• Ultra Capacitor (UC)
• Absolute crankshaft position sensor
• Direct injection system (E-TEC)
• Electrical machine (3 phase AC Generator acting as a BLDC motor also)
• Engine Control Module (ECM) to control the ultra capacitor charge
All components were already part of the vehicle’s design except the UC and crankshaft sensor. Added weight is only 2 lbs. compared to over 20 lbs. with conventional electric start.
How it works:
1. Rider pull-starts the snowmobile at the beginning of the day.
2. The electrical machine acts as a generator and through the ECM that converts AC to DC, charges a lightweight (1.75 lb/800 g) ultracapacitor.
3. For subsequent starts within 30 minutes of shutdown, the rider re-starts the snowmobile by pushing the SHOT button.
4. Energy from the ultracapacitor flows through the ECM (converting back to AC) to the electrical machine, acting as an electric motor, to turn the crankshaft.
5. The electrical machine and combustion engine get synchronized and the crankshaft slowly starts rotating until the 1st top dead center. The DI injector supplies fuel in a stratified mode while the ECM times ignition spark at the right position just after top dead center (TDC) and that combustion makes the engine rotate fast and start.
In conclusion, the SHOT system is simple, cost effective and easy to manufacturer since it uses mostly existing parts of the snowmobile electrical system. The innovation was introduced this spring with great market acceptance – 65% of models were ordered with this new system - and hailed as a game changer by industry insiders.
ABOUT THE ENTRANT
Name: Michel Bernier
Type of entry: team
Ski-Doo Engineering Team from USA, Canada and Austria
Software used for this entry:
Patent status: pending