Triaviathon measurments are obtained by temporarily surrendering the standard airworthiness certificate then receiving an experimental certificate. This allows the installation of a wing mounted boom and barograph for precise measurement of airspeeds. As you can see our Tiger top speed at 6000 PA was meaured at 173.4 MPH. You need have to have big engines, constant speed props, and retractable gear to beat the Tiger. Tiger 28220 was a cleaned up stock Tiger with no Powerflow exhaust, a McCauley propeller and no STC's. It was racing against other aircraft the owners considered fast and efficient. Click Zoom, original size to read the print. At the time of the race 28220's engine was over TBO and had about 600 hours on a top OH, Pressure altiude at the speed run was about 6000 feet. The object was to fly as fast as it would go in a level altitude, then as slow as it would go for the the best score. The 177RG bettered the Tiger mostly due to it flying slower at the minimum speed check. In order to read, need to Hover over the top of the page, hover over "Zoom" click "original size" the photo will enlarge.