Can an EFI 2-stroke using only a pipe sensor meet 2012 emission standards at the same level as, say, Ski-Doo’s E-TEC? According to Arctic Cat engine guru, engineer Greg Spaulding, the newest version of the 800 passes with flying colors.
Arctic Cat holds the patent on pipe sensor technology and although virtually every 2-stroke built, Cat or otherwise, uses pipe sensors to gain computer mapping data during its development cycle, the competition has been unable to use this technology in full production.
It’s a fact that most race sleds, even factory teams, use pipe sensors but you will not see this feature on full production sleds other than Arctic Cats without the company’s consent.
Pipe sensors read temperature data that interprets whether the engine’s ongoing fuel mixture is rich or lean. Since a lean engine is a clean engine and the mixture data is being sent to the EFI control module on a millisecond schedule, burn levels are regulated at virtually any RPM, under any load.
The trick was to remap the modified engine so it runs safe and secure at all levels while balancing the mixture so it is neither too lean nor EPA dirty. All this takes time and when you’re building an engine, the test and verification process can take a while.