I can’t achieve 85% on a Cirrus SR22 turbo (tornado alley) because I can’t keep CHTs under 380. I can only sustain 75% power. Here’re the parameters:
Pressure altitude: 6800
Power: 75% (2550rpm 29.6MP 15.6FF)
CHTs: 357 346 367* 347 350 326 (avg 349 spread 41)
EGTs: 1408 1456 1479* 1476 1423 1383 (avg 1437 spread 96)
TITs: 1555 1478 (avg 1516 spread 77)
If I increase the FF to 17.6 (85% power) CHTs overshoot 380 approaching 400 (til I lean again). I did (quick and dirty, so unreliable) lean test and EGTs peaked with a 19.1–19.8 FF (0.7 spread), though the peak EGTs ranged from 1614 (EGT3) to 1492 (EGT6) - spread of 122 (CHT3 383 CHT6 350). So I think the mixture / injectors are OK (assuming the lean test was OK).
Why are my CHTs so hot? =D
Why is the TIT spread so large? It seems that one side of the motor (CHT1, 3, 5) is hotter than the other side (CHT2, 4, 6) and this is backed up by the diff in TITs? Though EGTs (left vs right) seem to average the same (but maybe they’re affected less by cooling)?
Is the EGT spread of 96 normal? Does it indicate a problem in injectors / mixture? Or can it be because of cooling? (Does EGT spread reflect mixture imbalances or cooling more?)
Is the CHT spread of 41 normal? Does it indicate a problem of cooling? (Does it reflect cooling or mixture imbalances more?)
Why is cylinder 6 cold?
Why is cylinder 3 hot?
Can you guys sustain 85% cruise power? What fuel flow, OAT, altitude and CHTs? What’s a typical EGT at that setting?
Confirm that all (turbo) cirrus cruise numbers are LOP and you can’t operate 85% ROP because of the fuel flow restriction (no FF > 18)?
Why does the fuel flow restriction exist if you can go past the “red box”? Also, if I can climb full rich, why can’t i cruise full rich?