Mike spent the first week of May at Pittsburgh Power in Saxonburg, Penn., and while there replaced the pistons, added a variable geometry turbo, reprogrammed the ecm to manage the new turbo and did a series of dyno runs.
The nitty gritty:
• Piston swap: We replaced the existing 15-to-1 compression ratio pistons with 16.5-to-1 pistons. This higher compression set of pistons gave us a smoother starting engine and eliminated the thick blue smoke we were getting at cold starts. The higher compression pistons should provide us with an increase in power and efficiency.
• VG Turbo: The switch from a conventional turbo to a Borg Werner variable geometry turbo will give us more power, while using less fuel. It will flatten the boost curve and increase the maximum torque range.
After installation of the pistons and turbo, the engineering staff at Pittsburgh Power did some fine tuning, with the fourth dyno run resulting in 602 horsepower and 1805 ft/lbs of torque. As fuel efficiency is a priority over power, they actually cut back on fuel that had us at 653 horsepower and 1912 ft/lbs of torque.