There are tuners and then there are tweakers. Sriyantha Weerasuria of Elite Motorsports in Austin, Texas, considers himself the latter. He’s actually more. MTI in Houston did build the engine and modified the drivetrain on his 9-second hardtop. But Sriyantha, who friends call S.W., did the rest.
   S.W.’s goal was to build the fastest C5/6-speed. "I set my mind to have the fastest C5 around, especially the fastest 6-speed car. You can make an automatic run faster, but a 6-speed requires more driving skill."
  In typical fashion, S.W. is being modest. Turning a 9.98 second ET, he shifts gears at about 6,300 rpm. With the 135-horsepower shot of TNT nitrous engaged all the way down the quarter-mile, he stabs the clutch and grabs gears with the