M Engineering

From our testing and also doing lots of cars out in the field on various dynos, stock headers make the most power. This goes for both the Turbo and Carrera models. Aftermarket headers will raise EMAP pressures which hurts turbo response. We have verified this by adding EMAP sensors in aftermarket and stock headers and analyzing the data. It may be possible that in the future, different header designs may net some bigger power gains but we have not seen that yet. It's generally not until you have full-frame turbos with built-motors where you need to add headers to the car for more power.

-Charles@M