As a result of 5 months, many many hours of testing, hours of analyzing, many hours of making changes, 30 gallons of fuel, three blown belts, broken secondary rollers, costly sensors, working in between other jobs, here is the list of things found and the results.
RH side of the motor was low and back. Raised the motor up closer to perfect. No change in temps.
Found c/c to be 11.573". No change made as there was no way to adjust c/c distance without replacing TCL bracket. Unknown if replacement would bring c/c to spec.
Found secondary sheaves out of true (.012) caused from prior belt failures or heat cycles. Machined faces. No noticeable change in temps.
Noticed end of secondary moving downward under load. Installed torque stop. Reduced downward movement dramatically. No change in belt temps.
Also installed D & D Racing left rear Polly motor mount for additional support.
Replaced OEM Arctic Cat 082 belt with a Carlisle 144-4640 belt. immediate 61 degree reduction in belt temps. Drive and secondary temps also reduced.
Still noticed some movement at end of secondary. Changed jack shaft to a Belanger Racing Products first generation jack shaft. No change in secondary movement.
Installed a Micro Belmont large diameter jack shaft. Nearly all movement eliminated at end of secondary. No provision for reverse mechanism.
Installed EVO manifold and turbo exhaust wraps. Noticed a big decrease of radiant heat coming from under the hood.
Set clutch offset by running clutches without retaining hardware or shim washers to determine secondary float position. Recorded belt temp.
Moved secondary in from float position .040". Belt temp increased 25 degrees.
Moved secondary out from float position .040". Belt temp increased 25 degrees.
Installed Belanger Racing Products second generation jack shaft as it has a larger than OEM mid section diameter and has reverse provision.
Installed a Carlisle XS 822 belt. No change in belt temps. Clutch movable was 108 degrees and secondary was 115 degrees. Noticed a 3 horsepower increase at the jack shaft over the 144-4640 belt at the same ratios.
Free spinning, no load speed, created belt temps of 175 degrees. Full load at the same speed (1:1) only increased belt temps 5 degrees.
Installed a Precision Auto Research belt slip sensor to record belt rpm's. Math channels were added to record belt slippage. Very little (2%) slippage was detected. Clutches have good power transfer and react nicely to changes in load.
Installed a lighter secondary spring. Belt temps increased.
Installed a heaver secondary spring. Belt temps increased.
Checked overdrive of the XS 822 belt. Found it to be 15% with this c/c distance. With stock 22/37 gearing, top speed calculates out to 131 MPH.
Recommended belts for this sled have had as much as 24% overdrive.
We will be installing Autolite iridium spark plugs in this 1100 as they have produced an additional 3 hp gain in two of our two stroke race motors.
All things considered, the longer belt had the biggest influence in belt heat reduction. Heat radiated from within the hood is of great concern for all things under the hood, including the belt. Clutch movement was suspected as a high likelihood of short belt life. Anything that can be done to better align the clutches, and keep the clutches in alignment, should have positive belt life results.
Thanks to all that have contributed to this project.
This concludes the dyno phase of the test as we have a Polaris race sled to dyno and a new Arctic Cat Snopro to build for the MIRA races and the Soo 500.
We will start another thread to continue with field testing of this sled when we get snow.
Questions? Comments? Fire away!
