As many of you have seen from a few leaks on other threads, I have been experimenting with a technique called variator notching. The idea behind it is to elongate the roller ramps. This enables the rollers to travel further thus pushing the pulley faces closer together and allowing the belt to ride all the way to the top of the pulley face.
On my initial trial with just roughly filed and sanded ramps I used my Dr. Pulley sliders and did actually get the belt riding up higher on the pulley faces, but still about 4mm from the edge. Previously it had been running almost 8mm from the edge. I also gained about 2-3mph faster top speed as compared to the Malossi multivar I run normally. I tested this by taking a permanent marker and drawing radial lines across the variator face and measuring how much of the line was left after the test run.
I was pretty exited about my first test run with the stock notched variator as it seemed to out-perform my Malossi! I then proceeded to file and finish sand the ramps smoother. In doing so, I ended up removing a little bit more material off the ends of the ramps. I also took about .3-.5mm off the center of the face side to allow the pulley halves to come a little bit closer together.
With high hopes I re-installed the notched variator this afternoon to give it another test run. I started the scoot and reved it a bit while on the center stand. Then there was a change in noise, and the engine wanted to stall, didn't sound good! I immediately killed the engine and pulled the cvt cover back off. Two of my sliders had wedged sideways at the end of the ramp!
For now I'm going to have to call my experiment a Fail! I still have reason to believe that this technique works and if done the proper way will out-perform many of the performance variators on the market. I think I just took about 1mm too much material off! I think even the way mine is now it may work with rollers instead of sliders. I just don't have any rollers the correct weight to get a good comparison right now.
I think that ultimately, variator notching does work and is a viable performance enhancement if done very carefully! It may take a bit of trial and error to get it right. If you're on a budget and are considering buying a performance variator anyways, you may as well give it shot. It could very well save you some money! If it doesn't work, you're back were you started buying an new performance one! I will however say that it is a very time consuming process and there is no way to really make it any faster. If you try and remove too much material too quickly you'll most likely screw it up! Take your time with a file and sandpaper, don't bust out the hacksaw and dremel!
I'm attaching a few pics. The first one is of my roughly cut ramps. This is the point at which I made my initial test. Second is the after much more sanding and filing. The cut aways are a little larger at this point, but this allowed for a smoother ramp. This is the point at which I had the slider get wedged. Third is of the face showing where I removed the .5mm around the center.
