ZU-TAD has been modified to the new aircraft with the 915 engine. The fuselage is a standard Sling 4 fuse, the wings, elevator, engine cowling and prop. have been changed. Early testing shows it cruises at 140-145 indicated, TAS 150-155 kts, really gets along. They are calling it the "TSI" which stands for "Turbo Speed Injection " or may be Injected.