Performance Air Filter for Porsche 911 964 (1990-1994) 3.6LYour air cooled flat six deserves more than a disposable paper gag; give your 964 the clean, high volume airflow it needs to sing at redline without compromising engine protection. Performance Replacement Air Filter for Porsche 911 (964) (M64 Engine) If you own a 964 Carrera or RS, you understand that the M64 3. 6L engine is a masterpiece of air cooled engineering. However, the factory paper filter hidden inside that black plastic airbox is designed