Air-Side Thermodynamic Margin as a Governing Factor in High-BMEP Diesel Combustion Stability

This work documents experimental observations and system-level analysis of air-side thermodynamic margin as a governing factor in high-BMEP diesel combustion stability.The manuscript focuses on the interaction between intake air temperature, charge density, intercooling effectiveness, combustion phasing, and mechanical loading in turbocharged compression-ignition engines operating beyond nominal factory calibration envelopes. Particular attention is given to the role of increased air-side thermal reserve in suppressing combustion instability, extending usable torque plateaus, and enabling higher effective BMEP without inducing knock, hunting, or abnormal pressure rise rates.The work is empirical and engineering-led, integrating thermodynamics, mechanical limits, control behavior, and total system effects rather than isolated component optimization. It is intended as defensive prior art and as an open technical reference for engineers and researchers. No proprietary or confidential information is included.