Greg,
Sorry to hear that. Maybe the turbo does have something to do with it. There was only one difference I found with my throttle. My prop was set to allow the engine to reach a maximum of 5500RPM at max throttle. After I installed the balance tube, the engine would reach max RPM at about 95% throttle. The last 5% would not give me any more RPM. I experienced no loss in power though, since I was still getting the 5500RPM. Just reached full power at 95% throttle. Throttle advance was smooth throughout.
One thing you might try is pinching the rubber hose a little bit with a clamp and see if you notice any improvement. If you have to restrict it a lot though, you may be just as well off with the factory tube. Just guessing here but you might be right about the location. Can't imagine why though, some balance tubes are located on the very opposite end of the manifold from the carbs.
Hate that you did all that work with no results. Maybe it will work on your friends plane.
Keep me posted.
Bill.
