The GruppeM Carbon Fiber Intake for the E46 M54 engine has a unique design. The K&N filter is covered by a carbon fiber heat shield (Figure 4), which only allows air to enter the filter from an empty space in the engine bay secluded by a metal frame (Figure 3). This space is extended to the empty area behind the right fog lamp (Figure 2). The duct beside my right foglight (Figure 1) leading to this empty area provides an ample supply of fresh air for my intake (Figure 2), improving throttle response and power delivery.

The sound of the intake is a tremendous improvement over the stock sound. It has a deep, throaty grumble in low rpm and growls loudly from midrange rpm to redline. I don’t have to worry about droning while I’m cruising in the freeway because unlike an exhaust, which has at least some droning when the throttle is closed, the intake doesn’t produce any droning and only growls when I punch the throttle, which I am very happy about.