The GTk Active Muffler Line from Ächtung Kraft is designed to deliver unparalleled performance and to six sound options in one muffler for all your Air-Cooled Porsche 911, SC, 914, 964 and Carerra. 

This version delivers the same performance and sound quality of our original GT3 style GTk Muffler with a wider 11" Wide RS Style Center exit. 4 distinct active sound levels allow you to tailor your driving experience to match your mood and driving conditions.

Our original style of GTk Active Muffler with a sleek and sporty GT3 style center exit design and 4 modes of active sounds at the touch of a button. This muffler started the GTk line after 3+ years of development and testing to deliver an amazing sounding muffler for your flat-six.

This style bolts up to your single out stock exhaust and exits in the same side-out location as a stock muffler on 911 SC and other 1975+ 911s. It provides easy installation without the need for additional modifications. It offers 6 distinct sound levels at the flip of a switch. Tailor your driving experience to match your mood or the driving conditions.

A more aggressive look and sound, this 1-IN GTk Active Muffler offers a center-out GT3 style exit. This muffler delivers a bit more of an aggressive level of sound and performance than the side-out stock location variant, with the added benefit of a sleek and sporty GT3-style exit design. This muffler offers 5 modes of active sounds at the touch of a button.


We didn't settle duplicating 50 year old designs. We instead leveraged advanced technology to create a whole new solution to air-cooled muffler design

In-depth CAD & CFD design process

Advanced design technology delivered new advancements in muffler design

State-of-the-art analysis coupled with thousands of miles of road testing created the perfect blend of performance and sound quality

At Achtung Kraft, we believe in harnessing the power of cutting-edge technology to design the best mufflers. That's why we utilize advanced Computational Fluid Dynamics (CFD) and Computer-Aided Design (CAD) techniques throughout our design process. By leveraging CFD simulations, we can analyze airflow and optimize the internal structure of our mufflers to maximize performance and efficiency. With CFD and CAD and thousands of road testing miles, we can confidently say that our mufflers are not only visually stunning but also deliver unmatched performance and sound quality on the road.

Disclaimer: Please note that our products are designed and intended for off-road use only. The use of our products on public roads and highways is prohibited by law in many areas. It is your responsibility to ensure that the use of our products complies with all applicable laws and regulations in your area. Any use of our products on public roads and highways is at your own risk and could result in damage to your vehicle, injury or even death. By purchasing and using our products, you acknowledge that you have read and understood this disclaimer, and you accept all responsibility and liability for any consequences that may arise from the use of our products.

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