11/09/2026
TAPP Snowmobile Primary Clutch Tuning - Part 4 - Setup and Performance Tuning
In parts 1-3 we covered the components that can be changed/ adjusted on the TAPP Snowmobile Primary Clutch. In this final part of our TAPP primary clutch series we’ll discuss some setups and performance tuning tips.
Let’s begin with the most common trail setup with the 998 Turbo engine as an example. Most of these sleds with trail tunes will use the Blue TAPP spring and the +1 rollers. Ramps should be set to the A side. Weight can be added with Allen Screws in the swing arms to refine the RPM as desired. Start with the clickers in the 3 position and adjust as desired. This is a great baseline that will yield smooth engagement and excellent trail manners.
A quick note on the two spiders available in the TAPP primary. The most common version is the button spider. A roller spider is available at an additional cost. Due to the extremely low friction of the roller version, it will run at 500-600 rpm lower than a button version on a sled tuned around the 300 hp level. Our preference is to use the button spider on sleds up to around the 350 hp level. We’ve found that the button spider works very well, runs quietly, and keeps the clutch closer to the center of the tuning window for the vast majority of sleds. For those wanting maximum performance at higher horsepower levels, the move to the roller spider is appropriate. We used the button spider on one of our demonstration sleds tuned to the 400 hp level for years with excellent results. On our 500+hp race sled, we use the roller spider.
A couple of more notes on friction and efficiency. Unnecessarily stiff springs and heavy weights in any clutch lead to more friction, more wear, and less efficiency than softer springs and weights. Stiff and heavy tuning components result in the clutch fighting itself and less energy is transferred to the sheaves and belt. For the highest performance and hp to the track, use the softest springs and lightest weights practical.
In the TAPP primary clutch, these efficiency considerations also come into play with the ramp. We mentioned in part 3, that the B side of the ramp will “pull harder” due to its flatter profile curve. That, and higher engagement, are the reasons why racers prefer the B side. The steeper the curve and angle the ramp, the more energy is lost in the clutch and less power is transferred. That is why steeper ramp angles run higher RPM. The clicker setting influences this as well.
Most tuners will prefer to set up their TAPP primary so that they most often run with the clickers in the 3 or 4 position. This gives them some tuning window to go up or down. However, setting the clicker in the 1 position lowers the outer edge of the ramp resulting in the flattest profile. For maximum efficiency and power transfer, racers may want to setup their clutch to run with the clickers on 1, adjusting the weight on their arms (reducing) if necessary to hit their desired RPM. Clickers on 1 will give the highest level of power transfer and performance. The trade-off is having a smaller quick-adjustment tuning window to work with.
Moving from the ramp to the rollers, there are performance considerations there as well. The most common setups use +1 or +2 rollers with a shorter bolt and fewer washers. This type of setup yields excellent long term durability with the majority of the weight centered in the shift arm directly on the ramp. However, larger diameter rollers change the relationship between the swing arm and the ramp, increasing the distance between the center of the roller bolt and the surface of the ramp. What we discovered on the dyno is that this increased distance led to decreased efficiencies in the clutch and less track horsepower. Increasing roller size (and associated weight) is an easy way to configure the shift arms. However, using smaller rollers and adjusting the weight of the arms with a longer bolt and washers to compensate, can yield higher performance in race applications where every little bit counts.
We discussed the springs in detail in part 1 of this series. To recap, trail riders will prefer the Blue spring with its lower engagement and smooth shifting characteristics. Racers will most often move to the Brown or Black spring, mostly to help raise engagement RPM so they can build more boost when using a 2 step or launch control function.
There are so many ways to setup your clutch that there is likely no “one best” combination. The best results will depend on the sled, track length and traction, sled modifications and desired riding style, snow conditions, etc. etc. etc.. The number of possible combinations is almost mind-boggling. Our hope is that you’ve found this series on the TAPP Primary Snowmobile clutch helpful in providing you with some more information on what is possible for optimizing the performance aspects that are most important to you.
