Porsche is trying to build excitement around its upcoming rival for the Tesla Model S. On Monday at the Electric Vehicle Symposium in Stuttgart, Germany, Porsche revealed the Cayman e-volution, an all-electric research car that previews the Mission E, which is set to launch in 2019. Although Porsche didn’t release any information regarding the e-volution’s power output, it revealed that the battery-powered Cayman can accelerate from zero to 100 kph (62 mph) in 3.3 seconds. The gasoline-powered 718 Cayman, for perspective, takes 3.9 seconds just to reach 60 mph, even with Porsche’s available PDK automatic transmission. In addition to previewing t... NESN.com