Due to the poor efficiency of the factory charge air cooling system on the 998 Cat/Yamaha, intake air temps climb rapidly on longer runs, which is made worse with an increase in boost/horsepower. This increase in IAT has shown up to a 40 horse loss on our dyno with a loss in boost and overly rich A/F mixture starting at IATs around 100 degrees F. With the stock cooler, trail sleds can see in excess of 120 degrees, even in winter temps. On the dyno with a high velocity fan, we have seen 170 degrees.
We developed 2 different intercoolers to help with this issue, both are as close to a direct fit as possible, using the same mounting tabs and same size/location charge tubes.
We have a 2.25 inch thick core, designed for completely stock sleds with no tune, up to approximately 270 horsepower, and a 3 inch thick core for sleds regularly running 270 horses and above with a theoretical max of 450 horsepower per Bell engineers.
The 2.25 core averages 7% more airflow, measured on our Superflow SF-110 flow bench. the 3 inch core averages 15% more airflow than stock.
On our dyno, the 2.25 showed approximately a 15 degree drop in IAT over stock on a 10 second run and the 3 inch showed a 25 degree drop over stock. This equates to less horsepower loss over run time, verified on our dyno.
These coolers were designed in conjunction with Bell intercooler and are manufactured for us by Bell. They are bar and plate design with high efficiency fin design, and constructed of 3003 aluminum for strength and high corrosion resistance.
Both coolers come with our intercooler vent for the panel behind the cooler, which is worth a few degrees drop in IAT on it's own, but even more when combined with an upgraded core.
For installation, take the 2 rubber grommets that the bottom of the cooler mounts in, and flips those upside down and trim as needed to get the retaining clips back on.
Trim the front, lower plastic panel on the surface that contacts the cooler face. remove enough so that the plastic does not touch the fins. Amount of trimming will vary, depending on which cooler you are installing.
For the 2 inch core, minor trimming in one small portion of the hood MAY be required. Check fit first as it seems that some sleds make slight contact, and others dont.
This isnt rocket surgery, so dont overthink it! If there is any interference or contact, simply trim it.