All too often OEM components must sacrifice various performance minded characteristics in an effort to appeal to a wide variety of customers. While an enthusiast typically wants better boost response and more power, all while hearing the turbocharger breathe, a non-enthusiast may give up these characteristics for a quieter ride. In the case of the factory IHI turbocharger, a turbo muffler, or Pulsations-schalldämpfer, is positioned at the compressor outlet and is designed to reduce engine bay acoustics.

The APR Turbo Muffler Delete replaces the factory muffler with a straight, uninterrupted piece, CNC-machined from billet aluminum and anodized black. To ensure proper sealing, APR’s engineers took a two-part approach. A Viton seal is included and forms a seal between the base of the muffler housing and the new piece. With the seal in place and the outer flange installed, the muffler delete tube screws into place, forming a full, uninterrupted path for airflow.

APR's 2-Piece Design Explained

As is true with all machined parts, it’s impossible to make all parts the same. In the case of the turbo muffler housing, the distance between the bottom and top of the muffler’s housing will vary from turbo to turbo. The acceptable measurement range is known as a tolerance. The nominal distance between the top and bottom of the turbo muffler’s mounting points is roughly 51 mm. The tolerance on this part can be as loose as +/- .5mm or more. This means some muffler housings will be up to 51.5mm tall, or as low as 49.5mm tall.

Since the distance between the top and bottom of the muffler chamber will be different on every turbo, a 1-piece turbo muffler delete will always be either too tall or too short. On systems that are too tall, the delete will touch the bottom but will not touch the top mounting point, creating an imperfect seal and potential for a boost leak. If the part is too short, the system will seal at the top, but will leave a small gap at the bottom, thus negating the purpose of the part as illustrated in the diagram below.