VE more than 100%

Hello and thank you so much for the amazing course.

You mentioned that race engines can have an efficiency of more than 100% due to compressibility of air. I totally agree, but how would we compress air without forced induction ?

Thank you in advance.

Regards,

Due to the flow characteristics of air, which(as far as I know) are quite similar to the ones of water, a naturally aspirated engine can create a vacuum with so much force, that even after the cylinder is 100% filled, the air still has its momentum and keeps flowing and therefore compressing the mixture in the cylinder further.

I appreciate your answer mate. Thank you !