MTNTK Releases Tunnel Shortening Kit for Polaris Mountain Sleds
It’s not all that unusual for the OEMs to take notice of custom modifications being developed by users and in the aftermarket and include them in future versions of their sleds. Fitting a track with a 3″ paddle on a production sled is a prime example of adapting what the aftermarket and custom mod community had already been doing and including it as a factory option.
In this case however, aftermarket company MTNTK Performance, has taken cues from what’s already available on a production sled—Ski-Doo Summit Expert Package—and adapted it to the Polaris platform. They’ve developed a tunnel shortening kit, which will allow Polaris mountain sled owners to shorten the length of their sled’s tunnel for better performance.
Yes, there were already some sledders in the community experimenting with tunnel shortening before BRP brought the Expert Package to production. But many more will surely follow suit with the availability of a clean and simple kit. If the Summit Expert is any indication, there are significant performance gains to be had.
Below is the press release from MTNTK Performance about their new kit.
MTNTK Releases Tunnel Shortening Kit for Polaris Mountain Sleds
Ashton, Idaho (August 27, 2019) – MTNTK Performance is pleased to announce new for the 2020 snow season the MTNTK Performance Tunnel Cut – Tunnel Shortening Kit.
As snowmobilers search for the ultimate in riding performance, any modifications that decrease drag and improve handling in the snow are paramount. Reduction of drag at the rear of the sled by shortening the tunnel and or the snow flap is a current trend among the bravest to get the most out of their machine. By reducing the amount of the chassis that could potentially drag in the snow the sled handling is improved especially when performing advanced maneuvers on the hill such as sidehilling, and reentry turns especially in deep loose snow.
The MTNTK Performance Tunnel Cut – Tunnel Shortening Kit allows owners of Polaris mountain chassis snowmobiles model years 2011 through 2020 to perform the modification without welding. Currently, Polaris uses a welded extrusion heat exchanger that doubles as the chassis tunnel support and structure. Any modification to this structure also modifies the cooling system and potential for leaks becomes evident. The MTNTK Performance Tunnel Cut – Tunnel Shortening Kit allow the customer to shorten the tunnel without the need for specialized welding or cutting tools and allows for a professional finished appearance, enhancing the snowmobile in the process.
Features and Benefits:
- Allows shortening of the chassis/tunnel with common and basic tools
- Completes the cooling system circuit crossover without any welding
- Does not automatically require different cooling system strategies i.e. additional coolers, etc
- Allows customers to add additional cooling if they so desire i.e. MTNTK Tunnel Cooler, etc
- Strengthens the tail of the tunnel and replaces the tunnel cap with a stronger and more durable assembly that is designed to handle track contact that can be more common when cutting the tunnel
- Allows the use of the stock bumper or most any aftermarket bumper designed to work with the stock tunnel
- Two positions for the stock bumper are built into the design, OEM distance from the bumper to the flap and retracted, which is 1″ tighter for the ultimate in reducing overall length
- Less expensive and far less labor intensive than any other solution on the market with an install time of approximately 2 hrs. excluding sealant cure time
- Two snow flap mounting positions allow the mounting of the OEM Polaris 2.6 track flap in the original placement or the install of many aftermarket or custom snow flaps in both the original placement or in a horizontal placement for additional snow clearance




This kit was designed as a reasonable cost solution to shorten the tunnel on late-model Polaris snowmobiles. The basics to installing the kit are as follows in a few simple steps: draining the coolant, cutting the tunnel off square with no complicated cuts, cleaning and de burring, installing the extrusion adapters with adhesive and crossover hose, installing the tunnel cap/hose protector and refilling the cooling system.
Retail price for the MTNTK Performance Tunnel Cut – Tunnel Shortening Kit is $299.99 USD. It is available for pre-order now, with a ship date of September 16, 2019.