Hi, I have no experience with what happens when you upgrade to the 220 HP engines. As I read the Turbo Plus webpage it seems to indicate the STC requires the installation of a Continental KB fuel system and an intercooler system. It looks like the TurboPlus intercooler system costs an additional $12,690. I don’t think that price includes installation.
I understand that the STC does up the MTOW by 170 pounds; if that’s the goal of buying the STC I recommend you find out how much the intercooler installation and cowling mods weigh to determine your true gain in EW.
I don’t know if you’ve taken a look at the Merlyn Products Black Magic automatic wastegate controller yet but what it does for the CHTs and altitude performance is almost magic. Replacing the fixed wastegate system on your engines with the Black Magic system will lower your CHTS and provide sea level MAPs up into the mid teens.
It won’t get you more useful load but it’s will definitely be better for your engine than the stock system.
