With a CVT clutch vehicle you must verify clutching performance with a peak RPM test after adding performance modifications, changing tire size/weight, and of course when setting up your new AA S1, S2, S3, or S4 Clutch Kit. This will ensure your setup is working properly for the best combination of power transfer and belt life. On your setup guideline we will list for your vehicle the proper range for peak RPM. Keep in mind the range usually changes for a stock tune vs one of our tunes, as we allow vehicles to rev higher and produce better power at higher RPM.
Testing: Find an open area or road where you can safely test. From a dead stop or 10 MPH rolling start, do a wide open throttle run to 60 MPH. As you pass 50-55 MPH, look at your tachometer and make note of your max RPM. This is the best speed to check what we refer to as “Peak RPM”. This is our constant that tells us how the clutching is set up. For example, see below the wide open throttle pull on our Can-Am:
Most times we will leave the clutch cover off and test on a paved road, this way any changes can be done quicker. Often times with more powerful turbocharged UTVs, we prefer to do a 10-15 MPH rolling start so the tires don’t spin as much. You can be in 2WD or 4WD. Make sure you are within our guideline spec for RPM. If you are, great! If not, adjust weights accordingly.
AA clutch weight adjustment: If your RPM is too high you need to add more clutch weight. If your RPM is too low you need to remove clutch weight. For more on this see this article: https://aftermarketassassins.com/tech-blog/f/clutching-holy-grail#
Don’t be afraid to adjust! Simply mimic what our setup sheet calls for. Say your magnet setup was 4/3/3 but you needed more weight, It’s really not going to change much going 4/4/3 or 4/3/4. Either would work great. Same with subtracting weight. Just try to keep the weight placement on the arm like we do, or if possible find another setup on the spreadsheet that has 1 more or less magnet and go with that. Many are afraid they will place the magnets in the wrong spot, and it’s really not that crucial when adding or subtracting 1-2 magnets. Having the correct peak RPM is the 1st thing to worry about, and then if if feels lacking in an area we can change magnet placement.
Dune clutching vs Trail Clutching: Dune setups like more RPM, while trail clutching often times likes a little less. We’ll use an RZR Turbo as an example. When tuned, we call for 8400-8600 RPM peak. Anywhere in that range works great for dunes or trail. If you want to be overly picky with your setup the best trail setup is more in the 8400-8500 RPM range as you will get the best top speed, load the motor so it creates boost better, and get more belt pinch for lower speed crawling. Dune riding is more the opposite as you have a load (because of the soft sand) even at higher RPM, so you will see cooler belt temps and better performance with higher RPM around 8500-8600 in the dunes. This is true for most CVT vehicles when running on trails compared to sand. Moral of the story is if you have time to be picky with your clutch setup, use our lower end of the RPM range for trail riding, and our higher end for dunes/sand.
– Mike