I don't think you understand what Peter intended to do by passing fuel through through one intercooler stage. He was trying reduce intake charge temperatures. This varies considerably compared with heating the fuel through a turbine engine oil cooler as is commonly done on production aircraft. With the 7 to 1 PR required at FL250 and the turbos he's selected, the CDTs will exceed 400F easily. This coupled with the intake mass flow, represents a huge amount of energy to be dissipated. The fuel could reach critically high temperatures in the space of less than a couple of hours. Don't consider comments here negative but rather a reality check on Peter's projections. We already know that his range and payload numbers can't be met because the aircraft is 1000-1200 pounds overweight. Something is gonna have to give in the TO, ROC and ceiling projections if he gets the payload back by raising the gross 1200 pounds more. We also know that the TAS vs. fuel flow numbers are highly improbable for an aircraft with this wetted area. These are inescapable facts. I've watched every YT vid on Raptor and just finished talking to Jeff Kerlo 2 days ago at Reno who gave me a lot more insight into this project. Do you have some technical details to add or discuss on this project which would put the previous discussions here on HBA in question?