I think people get twisted up in terminology. A 3350 is supercharged, superchargers are mechanically driven compressors. No 3350 has ever been turbocharged, turbochargers are exhaust driven compressors. The PRT was a turbine driven by the exhaust gases that was mechanically connected to the power section. Most 3350's have 2 speed blowers (superchargers), the lower speed is used at lower altitudes, the higher speed is used at high altitude cruise. I've never seen a 3350 that still shifts into second gear. When I was working on the bearcat we still had engineers that had worked for Wright when the 3350 was powering airliners helping us out. Despite all of the innovation utilized mixing and matching parts to get the absolute most amount of "reliable" power I can say we only ran the blower in low speed and if a turbocharger would've helped we'd probably have used it. There was another 3350 powered racer that tried PRT's, it had plenty of issues and I'm not sure it ever finished a race.