Tuesday, July 20, 2010
Cirrus SR22T: Turbo Without the STC
Cirrus Design now offers a turbocharged model with a factory Continental
Cirrus has been a consistent leader in producing aircraft that embrace 21st century technology, not only in construction materials and techniques but in avionics, aerodynamics and creature comforts. The Columbia (now Cessna Corvalis) line of singles and the Diamond models have brought new ideas to the marketplace, enticing buyers with more options. While changes haven’t all been earthshaking, they’ve represented a steady improvement in the breed. Cirrus has chosen to introduce new features one at a time, as they’re ready.
Such is exactly the case with the new Cirrus SR22T. Cirrus Aircraft recently flew a new 22T out from the factory in Duluth, Minn., for us to fly. In my job evaluating airplanes, I meet a variety of check pilots, and Matt Bergwall was one of the most thoroughly prepared I’ve come across. He was way ahead of me on every question, and there was nothing he needed to refer to the factory. It’s nice to work with pros.
Accordingly, Teledyne Continental Motors began work a few years ago on a big-bore, TSIO-550 engine that would run on lead-free, 94 octane avgas. The new mill, technically known as a TSIO-550K, employs a 7.5:1 compression ratio rather than the standard 8.5:1 ratio employed on the 100 octane LL engines.
The new Continental is rated for 315 hp at 2,500 rpm and 36 inches mp continuous, and retains that rating all the way to cruise height. Once you’re off and headed uphill, you can pretty much set power and forget it. (In the full-blown version, currently utilized on the Lancair IVP, the engine is rated for 350 hp at 2,800 rpm and 38 inches mp).
In order to maintain cool heads under the cowling, the new 550K utilizes several minor mods to improve airflow. The updated TCM powerplant mounts additional NACA vents to streamline cooling flow and some other minor cowling mods. There’s also a minor mod to the nosewheel fairing.
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