Hey RadarMan, I forgot where that post was about the DC-7
Any way, the DC-7 had R-3350 turbo-compound engines. Each engine had 3 PRT's (Pressure recovery turbines) Thes things put out about 200 additional HP each!!! What's different about them is that they are not turbos!!!! How they work is: Exhaust is routed into the turbine of each PRT. But there is no compressor that forces air into the induction system! Instead, there is a shaft that is connected directly to the engines crankshaft. So, the exhaust is pushing the turbine which in turn is pushing the cfrank!!!
Pretty cool hmm?
Sounds better than good, here is your post.