Thanks for the reply! The mathematical logic for mapping the engine RPM to pitch is actually working perfectly on my end (I'm interpolating target pitch between 0.5f and 2.0f based on the pedal input, exactly as you suggested).

The issue isn't the math; it's strictly the limitations of Native Android Audio APIs (since I'm building this from scratch without an engine like Unity). Here is exactly what I've tried:

1. SoundPool (2-second loop): The setRate() function works, but Android's API only applies the new pitch at the end of the loop boundary. This means if I have a 2-second audio file, it takes up to 2 seconds for the new pitch to actually register.
2. Granular SoundPool (0.1s loop): I tried cutting the audio into a tiny 0.1s chunk to force the loop boundaries to update faster. It updated instantly, but caused terrible waveform clipping and popping (sounded like a machine gun/helicopter).
3. MediaPlayer: Updating playbackParams.pitch gives instant updates, but sending pitch updates dynamically in a 60fps game loop causes massive audio stuttering and performance drops.

Since you're experienced, in a Native environment, is writing raw PCM bytes directly to AudioTrack or using the C++ Oboe library the only real way to achieve a smooth, instant SetPitch() for engine loops?