Our best performing 858 kit! making 50+ HP midrange gains and an an...
Turn your 858 into a rocket with this stage 2 kit! making 40+ HP...
Our stage 1 is no questions asked, the best bang for your buck in the...
PREORDER The ONLY aligned Belt drive assembly on the market for the...
Our Billet Head for the Arctic Cat 858 is an easy way to bolt on some...
This simple kit will gain 40+ horsepower over stock and still run on 87 OCTANE!!! Get your Thundercat just and get great fuel economy too! Just send us your ecu for a quick reflash, and then install our awesome new BIG FLOW 3" stainless steel muffler and clutch kit. This simple kit will gain 40+...
This powerful kit will gain 65-70 horsepower over stock and still run on 91 OCTANE!!! Get your Thundercat ripping and get great fuel economy too! Just send us your ecu for a quick reflash, and then install our awesome new BIG FLOW 3" stainless steel muffler, aluminum charge tubes, turbosmart valve, and our SSI clutch kit. This powerful kit will gain 65-70...
This powerful kit will gain up to 100 horsepower over stock and still run on 91-93 OCTANE! And its fully adjustable on the dash! Get your THUNDERCAT 9000 tuned up to the Max! Just send us your ecu and speedo gauge for a quick Hurricane reflash, and then install our awesome new BIG FLOW stainless steel muffler, aluminum charge tubes, turbosmart valve, 3... This powerful kit will gain up to 100...