mshafer
Well-Known Member
- Joined
- Jan 8, 2013
- Messages
- 425
- Reaction score
- 137
1984 PA32R-301T with the TurboPlus intercooller. Bought the plane and really had no idea how to run the engine with the intercooler. The TurboPlus documentation is sketchy at best and I called and talked to them and found they bought the STC and had no idea how it worked or how to run it.
I have a power reduction chart that is based on a reduction in MAP based on the amount of cooling I am getting displayed on the differential meter. Then, you adjust again based on the deviation from a "standard day" temperature.
This plane has a 50 hour engine in it with GAMI injectors. I also have a EDM-830 engine analyzer with 6 channels of EGT and CHT info along with TIT and fuel flow data.
Reading the POH and talking to GAMI and Lycoming, it appears the maximum TIT is 1600 degrees and Lycoming wants me to keep the CHT's under 400. The EGT's are irrelevant because the TIT gets to redline way before the EGT's do. The TIT redlines with the EGT's in the 1500 degrees range. The EGT's are very balanced andI have the # 4 Hotter Cylinder Head syndrome so that is a limiting factor as well.
The MAP redlines at 36.5 inches and the pop off valve is set right at that point so overboost is possible but not probable.
I get an average of 30 degrees intercooler differential during a moderate hot day, 50 degrees in the winter and 20 or so on a hot day. The MAP reduction is 1" of MAP for every 15 degrees of cooling on a standard day.
Here is what I do. On takeoff, I pull around 35 inches of MAP regardless of the cooling or temperature, 2700 RPM and full rich. Right after wheels up, I pull back to 32 inches or so and pull the prop back to 2600 and start leaning conservatively watching the TIT and CHT temps. I lean to about 1500 TIT and the CHT's get in the 360 degree range. On hot days in the climb, the CHT's rise and my # 4 cylinder starts bumping 400 degrees. I reduce my climb to 500 FPM or so until I get at least 115 knots of speed. The CHT's immediately come down.
When I level out, I pull the power back to either 65% or 55% based on the Lycoming power charts, adjusted for temperature and intercooling differential.. The engine is happiest at around 2400 RPM. I lean to 1550 TIT ROP or so. The CHT's are in the 350 - 370 range and fuel flow is around 19.2 GPH @ 65% power. At 55%, fuel flow comes back to around 16 +/- GPH but speed suffers and the CHT's come down to the 340-ish range
I now have 50 hours on the engine and the oil consumption has stabilized at about 8 hours/quart so I am calling it broke-in. I am going to attempt to run the engine LOP next flight using the LOP function on the JPI 830 instrument.
Right, Wrong or just right ?
I have a power reduction chart that is based on a reduction in MAP based on the amount of cooling I am getting displayed on the differential meter. Then, you adjust again based on the deviation from a "standard day" temperature.
This plane has a 50 hour engine in it with GAMI injectors. I also have a EDM-830 engine analyzer with 6 channels of EGT and CHT info along with TIT and fuel flow data.
Reading the POH and talking to GAMI and Lycoming, it appears the maximum TIT is 1600 degrees and Lycoming wants me to keep the CHT's under 400. The EGT's are irrelevant because the TIT gets to redline way before the EGT's do. The TIT redlines with the EGT's in the 1500 degrees range. The EGT's are very balanced andI have the # 4 Hotter Cylinder Head syndrome so that is a limiting factor as well.
The MAP redlines at 36.5 inches and the pop off valve is set right at that point so overboost is possible but not probable.
I get an average of 30 degrees intercooler differential during a moderate hot day, 50 degrees in the winter and 20 or so on a hot day. The MAP reduction is 1" of MAP for every 15 degrees of cooling on a standard day.
Here is what I do. On takeoff, I pull around 35 inches of MAP regardless of the cooling or temperature, 2700 RPM and full rich. Right after wheels up, I pull back to 32 inches or so and pull the prop back to 2600 and start leaning conservatively watching the TIT and CHT temps. I lean to about 1500 TIT and the CHT's get in the 360 degree range. On hot days in the climb, the CHT's rise and my # 4 cylinder starts bumping 400 degrees. I reduce my climb to 500 FPM or so until I get at least 115 knots of speed. The CHT's immediately come down.
When I level out, I pull the power back to either 65% or 55% based on the Lycoming power charts, adjusted for temperature and intercooling differential.. The engine is happiest at around 2400 RPM. I lean to 1550 TIT ROP or so. The CHT's are in the 350 - 370 range and fuel flow is around 19.2 GPH @ 65% power. At 55%, fuel flow comes back to around 16 +/- GPH but speed suffers and the CHT's come down to the 340-ish range
I now have 50 hours on the engine and the oil consumption has stabilized at about 8 hours/quart so I am calling it broke-in. I am going to attempt to run the engine LOP next flight using the LOP function on the JPI 830 instrument.
Right, Wrong or just right ?
