Potentially true, but could that performance be used? Climb rate might be much better, but if one intended to remain below sea level, one wouldn't be doing much climbing. Takeoff performance might be good, but there are few places to takeoff and land below sea level...and most of the time density altitude places them well above sea level.
On a standard day below sea level, the chance to overboost even a fixed pitch, normally aspirated engine does exist. Even though it's an unboosted engine, the higher manifold pressure below sea level may place this engine outside certification limitations. This begs the question as to weather or not the engine would need to be operated at reduced power due to excessive maximum manifold pressure.
On the subject of record setting, of course, one would be at maximum endurance, for the purposes of staying as long as possible below sea level. Performance would never be an issue.
However, if they ever hold air races at or below sea level, for normally aspirated engines...
On a standard day below sea level, the chance to overboost even a fixed pitch, normally aspirated engine does exist. Even though it's an unboosted engine, the higher manifold pressure below sea level may place this engine outside certification limitations. This begs the question as to weather or not the engine would need to be operated at reduced power due to excessive maximum manifold pressure.
On the subject of record setting, of course, one would be at maximum endurance, for the purposes of staying as long as possible below sea level. Performance would never be an issue.
However, if they ever hold air races at or below sea level, for normally aspirated engines...
