Starting Line Products has made a name for itself developing high-performance snowmobile parts since 1972, especially for Polaris sleds. In the 1990s, the company’s pipe setups were the hot ticket for XLT and Ultra triples. Three-cylinder two-strokes have since gone the way of the leaf spring front suspension, but SLP still builds high-performance setups for Polaris two-strokes like our 2010 800 Dragon Switchback demo sled with the 800 Liberty CFI engine.
Current SLP performance packages include exhaust, clutching, air intake systems, engine hard parts and more. Buyers can choose from several “stages” based on the level of modification and price. We tested parts included with the company’s Stage 2 and Stage 3 Tuning Kits last winter, so we’ll call our system a Stage 2-Plus.
Parts we tested are SLP’s ceramic-coated single pipe kit, which is a Y-pipe, pipe and silencer ($669.95); High Flow Intake ($128.11); and clutch kit with MTX adjustable weights ($129.90). We also installed a Dynojet Research Power Commander V (PCV) fuel injection module ($369) and a pair of lighter variable exhaust valve springs ($27) for use at elevation so the valves would open at the right time to maintain good peak-RPM performance.
Installation of the SLP parts went smoothly, but there are a lot of steps. Being careful to do a quality, thorough job, the full installation process took about six hours. Directions for each component were well-written and clear with decent pictures where necessary. We installed the weights as spec’d by SLP, and had to reset the belt-to-sheave clearance with shims because the SLP MTX weight’s profile changes the distance between the two sheaves.
Fit of the exhaust parts was excellent. The silencer set in place and was stable on the sled’s stock support bracket without contacting chassis or body parts. Even though the clearance between the silencer and chaincase cover was only about one-quarter of an inch, the parts maintained clearance throughout the season. The pipe’s diameter is larger than stock, so hood foam had to be removed to provide clearance, and then heat-reflective foil tape applied. Directions explicitly explained how to re-route the gauge-pod wires so everything fit well and parts didn’t melt. Installing the High Flow Intake was tedious and messy. Fortunately, the template is accurate to ease the pain.
The sled was even more fun to ride than it was in stock form. We felt more power from the engine and a mightier pull made it easier to lighten the front end and roost over a rise in the trail or out of a corner. It felt expertly tuned, especially during a trip to Cooke City, Montana.
There the engine was responsive. Engine speed quickly pulled up to the 8300 rpm peak and held there without lugging down. On mountain climbs, the sled ran out of traction far before the engine ran out of power, indicating that SLP did its homework on calibration specs.
The sled was a clean runner, too. Three Ski-Doo Summits with the carbureted 800R engine in a group we rode with in Wyoming always left a spot on the snow under the exhaust after idling, but the Dragon didn’t. This is an informal “test,” but worth noting.
We noticed after a few hundred miles that the foam tape that creates a seal between the air intake horn and the airbox opening was torn and separated. The piece didn’t get sucked into the engine, but SLP should include a more durable method to seal these parts because just the slightest misalignment when opening or closing the hood could cause it to tear like ours did.
Riding back home in Minnesota and the U.P. of Michigan with the stock exhaust valve springs installed and the accelerator pump turned on within the Power Commander, the engine ran nicely with a strong response. There was a slight gurgle when entering a corner – at about 5800 rpm. Perhaps with some further tuning with the Power Commander we could have cleaned that up.
The Power Commander was slick. Directions were pretty clear for installation and we were surprised at how specific they were for our sled in terms of where and how to mount it. Since the module is pre-programmed, we didn’t have to adjust the settings, except to switch the accelerator pump, which is part of the program that gives the engine a burst of fuel to prevent a lean bog when the throttle is whacked. To do it takes just a few clicks on a laptop computer equipped with proprietary software.