Rotax - iNR

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Captain's Report

Rotax iNR actuators
Shown here at a boat show display, BRP’s Intelligent Neutral and Reverse (iNR) uses electronic actuators (shown in the picture to the right) instead of mechanical cables and linkage to run the steering nozzle and reverse bucket.

Mission Statement


Bombardier Recreational Products (BRP) developed the Intelligent Neutral and Reverse (iNR) option for its Rotax Jet Propulsion System (JRP) to bring the precision of electronic control to jet-powered boats. It improves a jetboat’s slow-speed maneuverability, which makes the craft much more manageable in a variety of docking and/or trailer loading situations.


Rotax iNR running boat
Scarab offers iNR as an option on its jetboats.

Features Inspection


The Sum of All Parts. Intelligent Neutral and Reverse combines control of the electronic actuation of the reverse gates, BRP’s Lateral Thrust Control system and the ability to adjust the neutral position at the helm, giving a captain much better control than most jet propulsion systems have offered in the past.


Rotax iNR speed control
BRP’s iNR gives a captain better slow-speed control than traditional jet propulsion systems.

Fly-by-Wire. Traditional jet propulsions use cables to open and close the gate to direct the thrust that propels the boat. With iNR, BRP replaces the cables with wires that link the shift/throttle lever to electronic actuators that engage the gate on the jet pump. This increases the amount of control that a driver has because he can make more precise adjustments to the amount of thrust being used.


Rotax iNR actuators
The electronic actuators are protected in rubber boots, so they will last in saltwater environments.
Rotax iNR diagram
This diagram shows how the ECM controls the iNR system.

Adjustable Neutral. One of the biggest benefits of iNR is that it offers the driver the ability to adjust his jet pump’s neutral position from the helm. With conventional jet boats, it’s common for a boat to wander slightly forward or backwards. With iNR, the driver can adjust the neutral positioning in 1mm increments, so the boat will actually stay in place when in neutral.


Rotax iNR display
This multi-function instrument shows the range of adjustment increments for the neutral position system.
Rotax iNR shift and throttle
BRP turned to performance-boat accessory manufacturer Livorsi Marine for the digital shift and throttle control.
Rotax iNR gate
In this photo, the gate is in full forward position that lets the thrust exit the pump cleanly.
Rotax iNR adjusted gate
Here the gate has been adjusted for one of the neutral positions. Each click moves the bucket one millimeter.

Total Control. Adapting its iBR system found on Sea-Doo Personal Watercraft, BRP made sure that iNR delivers predictable deceleration when shifting into reverse while the boat is underway. If a driver accidentally pulls back hard on the control when the boat is running at speed, the boat won’t nose dive and slam into reverse. It’s another important element of control.


Rotax iNR boat running shot
If the Scarab 255 Impulse WAKE Edition is running at full speed, and the driver yanks back on the control, iNR will slow the boat in a controlled manner.

Improved Reverse Control. While iNR is new, BRP’s Lateral Thrust Control was already in use and has been lauded for improving a boat’s ability to maneuver in reverse at slow speeds. When the gate is in the full down or reverse position, it’s designed to direct the pump’s thrust to port or starboard when the steering wheel is turned, giving the driver much more control during situations that have traditionally been difficult for jetboats.


Rotax iNR
Chaparral offers iNR on its Vortex Series of jetboats.

Upgrade Price. On the Scarab 255 Impulse WAKE Edition, the Rotax iNR is a $640 upcharge. Chaparral charges an extra $625 for the system on the 243 Vortex VRX.


Observations


Eliminating cable controls is an important advancement in jetboat engines. By eliminating slack and the natural delay in controls, maneuvering becomes easier and more precise. We think it is definitely worth the upcharge.


The safety factor associated with jets (i.e. the absence of propellers) makes them attractive to family boaters. By developing such features as iNR and Lateral Thrust Control, BRP is eliminating the low-speed maneuverability issue and making jet-powered boats a real option to consider.