Skidoo's SHOT (Start Hot) system provides electric starting for Rotax E-TEC engines using a lightweight ultracapacitor instead of a traditional battery and starter motor, offering a significant weight saving.
Here's a breakdown of how this innovative system functions:
Understanding the SHOT System
The SHOT system is a unique electric starting technology developed by Skidoo for their snowmobiles equipped with Rotax E-TEC engines. It leverages the engine's own charging capabilities and a special component to provide reliable starting after the initial pull.
How SHOT Works: The Process
The operation of the SHOT system relies on two distinct phases: the initial start and subsequent starts.
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The Initial Start:
- The very first start of the day, or after the system has been completely drained, requires a manual pull using the recoil starter.
- During this first manual start, the running Rotax E-TEC engine is utilized.
- The engine runs its charging system which quickly charges a lightweight ultracapacitor. This ultracapacitor stores the electrical energy needed for later starts.
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Subsequent Starts:
- For all starts after the initial pull-start (while the engine is still warm and the ultracapacitor is charged), the SHOT button is used.
- When the button is pressed, the energy stored in the ultracapacitor is discharged.
- This stored energy is directed to the engine's magneto.
- Crucially, the system is designed so that the magneto temporarily functions as an electric motor.
- The magneto, acting as a motor, turns the engine's crankshaft.
- As the crankshaft turns, the E-TEC fuel injection system and ignition work together to start the engine quickly and efficiently without needing further physical effort.
In simple terms, SHOT uses the engine's initial pull-start energy to store power in a capacitor, which then powers the magneto (acting like a mini-starter motor) for easy subsequent starts.
Key Components
The SHOT system relies on the synergy of specific components:
- Rotax E-TEC Technology: Essential for its charging and control capabilities, allowing the engine to charge the ultracapacitor and manage the starting process.
- Lightweight Ultracapacitor: A state-of-the-art component that can store and rapidly discharge electrical energy. It is significantly lighter than a traditional lead-acid battery.
- Magneto: Typically used to generate electricity for ignition and charging, in the SHOT system, it also serves a dual purpose, temporarily operating as an electric motor to turn the engine for starting.
Practical Benefits
The primary advantage of the SHOT system over traditional electric start is weight reduction. By replacing a heavy battery and starter motor with a lightweight ultracapacitor and utilizing the existing magneto, Skidoo sleds can shed several pounds, which translates to improved performance and handling on the snow.
| Component | Traditional Electric Start | Skidoo SHOT System | Benefit |
|---|---|---|---|
| Starting Power | Heavy Battery & Starter | Lightweight Ultracapacitor | Weight Savings |
| Engine Start | Electric Motor | Magneto (acts as motor) | System Integration |
| Initial Start | Key/Button | Manual Pull-Start | Simple Design |
This system is particularly beneficial in cold conditions where traditional batteries can struggle and the weight saving is highly valued by performance riders.
