Carnewal GT Exhaust: A Big Mistake!

I still say the Carnewal GT exhaust is a good exhaust and a good value, but I made a really big mistake when calculating how much horsepower you get from it!

Carnewal GT Exhaust: https://bit.ly/3j7FvBT
Soul Performance Valved Exhaust: https://bit.ly/3wPsr7Y

(cat-back, relative humidity, barometric pressure, Porsche, Cayman, Project 987.2, catalytic converter, PDK transmission, launch control)