Hi everyone pretty new here but I recently have come across the chance to finish a Lancair IV that was estimated around 80% complete.  The road block atm is the IO-540 twin turbo that is mounted on it, the owner builder had some things engineered to properly install/fit everything so im not worried about that. I'm more worried about performance and fuel wit this motor than anything.  It would be nice to hear from someone that may have this motor on a IV, I understand why it isnt a choice for the P version I think but still trying to understand it all.

Any thoughts would help, Thanks