Stage 1R – Ultimate Stock Muffler Package

250 HP on 91-Octane Pump Gas

The Precision EFI Stage 1R is the perfect upgrade for riders who want a significant increase in performance without replacing the factory exhaust system.

Designed specifically to retain the stock muffler, the Stage 1R delivers an impressive 250 horsepower on 91-octane pump gas while preserving the quiet, refined riding experience that many trail riders prefer.

By combining our optimized ECU calibration with the Precision EFI High-Flow Air Intake, we were able to safely increase boost pressure and dramatically improve engine efficiency, unlocking performance that completely transforms the character of your sled.

The result is instant throttle response, exceptional low-end torque, and hard-pulling acceleration—all while maintaining the comfort of the factory exhaust.

Maximum Performance. Minimum Noise.

Not every rider wants a louder exhaust.

The Stage 1R was developed for customers who want serious horsepower while keeping their sled quiet for long-distance rides, early morning departures, and respectful trail riding.

If your goal is to retain the stock muffler without sacrificing performance, this is the ideal package.

Precision EFI Knock Protection

Every Precision EFI ECU calibration includes our proprietary Knock Protection System, continuously monitoring engine knock to maximize performance while protecting your engine under varying fuel quality and operating conditions.

Kit Includes

• Precision EFI Stage 1R ECU Reflash
• Precision EFI High-Flow Air Intake

Recommended Upgrade

We strongly recommend upgrading the Blow-Off Valve.

During development and customer testing, we've observed numerous failures of the factory blow-off valve under increased boost pressure. Upgrading this component significantly improves long-term reliability and boost control.

Clutch Calibration Required

To achieve the advertised performance, the Stage 1R requires adjustable primary clutch weights.

Proper clutch calibration is essential to keep the engine operating in its peak powerband, maximizing acceleration, horsepower, and belt life.

The recommendations below are intended as a starting point for sleds equipped with a stock primary spring and helix in good condition. Final clutch calibration may vary depending on snow conditions, gearing, altitude, rider weight, and other performance modifications.

Target Engine Speed

Target RPM: 9,000 RPM

Recommended Starting Point

• Dalton QAY-70 Adjustable Ramp Kit
• Adjust to a total weight of 73 grams
• Apply Purple Loctite to all weight screws.
• For most applications, position the adjustment screw with the head flush with the top of the heel pocket.

Clutch Adjustment Procedure

Perform a full-throttle acceleration while applying the throttle progressively to minimize track spin.

Once the engine RPM stabilizes, record the maximum RPM.

• If RPM is above 9,000: Add clutch weight.
• If RPM is below 9,000: Remove clutch weight.

Repeat the process until the engine consistently reaches 9,000 RPM under full load.

Because snow conditions, elevation, temperature, and track traction all influence clutch performance, minor adjustments may be required throughout the season to maintain the target RPM.

The Ideal Upgrade for Stock Exhaust Riders

The Precision EFI Stage 1R proves that you don't need an aftermarket exhaust to experience outstanding performance.

Delivering 250 horsepower on 91-octane pump gas, exceptional throttle response, and factory-like refinement, it's the perfect choice for riders who want big performance gains while keeping the quiet operation and appearance of the original muffler.