BENSTORF, Germany — SKN, the German tuner that specializes in electronic engine management, has unveiled a performance package for the Porsche 997 that is available in three stages. The Porsche's stock flat-six makes 473 horsepower and 457 pound-feet of torque, and SKN's Stage 1 treatment adds a new air filter and ECU tune to bump power to 512 hp and 527 lb-ft of torque. That means faster 0-to-60-mph times of less than 3.6 seconds for the six-speed manual and under 3.4 seconds for the Tiptronic S.Stage 2 manages even bigger gains, thanks to the addition of a special exhaust system, which helps bring power to 532 hp and 546 lb-ft of torque. The manual and Tiptronic S now sprint to 60 mph in under 3.4 and 3.2 seconds, respectively.Stage 3 replaces the Stage 2 exhaust system with a stainless steel unit with two three-in-one tailpipes. Power is further upped to 566 hp and 575 lb-ft of torque, giving the 997 an impressive power-to-weight ratio of just above 6 pounds per hp. A tenth of a second is further shaved off the 0-to-60-mph time, and the 997 will now be capable of speeds as high as 199 mph. SKN also offers custom wheels from OZ or BBS, upgraded shock absorbers and new springs for its Porsche 997 treatment. Pricing starts at $4,000 for Stage 1, and you can tack on about an extra $1,300 every time you move up a stage. Inside Line says: SKN takes the 997 to the next level with its latest tuning treatment. — Mike Lysaght, Correspondent