2019 Mufflers

Remember, there are some mufflers that actually flow better than an open pipe. Some of they Dynomax UltraFlo mufflers claim that.
Ahhhh, ya kind of beat me to it.
The best flowing race muffler is the one with the highest cfm flow rate. Hooker Max Flow and the Dyno Max Ultra Flow are identical I design and
Flow about the highest in a regular case.
Type into your search bar “Muffler flow charts.”

Did you think about asking the race car driver what they use?