DEVELOPMENT: 997.1 Carrera Exhaust Development Part 1

We are happily working with the Carrera community to build custom Porsche exhaust parts that meet expectations and fill any voids in the market where SOUL’s solutions can shine.

Here is what is on our agenda for the 997 Carrera exhaust system:

  • Affordable replacement headers
  • Bolt on tips
  • Valved exhaust system with delta from OEM+ to CUP car inspired at the press of a button, default valve operation being “quiet” mode.
  • Sportier side mufflers
  • Catalytic converter replacement sections

Midwest Performance Cars sent us their Carrera S for development – they had to have SOUL!

Meet Our Porsche Muffler

Following the extreme effectiveness of the mufflers used in our 987 / 981 exhausts to combat drone, we’ve applied the same design to a bespoke muffler for the 997 Carrera. With valves closed during cruising, there is no drone even with the factory cats removed — damn good stuff.

We looked at what is currently out on the market, and we wanted to offer the ability to go from “Cruising Sunday to Track Day” at the press of a button. The design of our Porsche exhaust channels exhaust gases through our mufflers for a sophisticated and sporty sound that is unmistakably Porsche with valves closed, and this is the default operation setting. With valves open, you’re getting a CUP-inspired straight pipe sound. We designed this system with the default orientation of the valves in the closed setting when first starting – so when you fire up your car in the garage in the morning, you won’t wake up the entire family.

Here you see us building our prototype valved exhaust. We build our fixtures out of thickgauge aluminum, which is expensive, but aluminum acts as a great heatsink during welding to ensure we get perfect fitment.

Below you see casting templates that we use to verify fitment during the “kitting” process before welding the system together. We chose pink casting material as our supplier supports breast cancer awareness with this color option.

We’ve tested our Porsche Carrera exhaust system with factory catalytic converters and HJS HD 200 cell equipped replacement catalytic converter sections. We believe this is a great sound with the factory cats in place. Altering the cats can move the valves open loudness into race car territory with excessive volume and a hint of “angry trumpet” (imagine complete muffler bypass pipes) so we believe this to be a solution for the stock converter folk. We plan on offering a simpler, non-valved muffler solution as well, which is more suitable for those looking for a bit more volume from their existing factory setup, or those who plan on wanting to upgrade or remove the catalytic converters for a freer flowing option without getting too aggressive.

Here we are testing the volume of our Headers, Valved Exhaust, and Sport Catalytic Converters – quite loud with valves open!

And here is just the Valved Exhaust:


Catalytic Converters

You may already know of HJS catalytic converters – but if you don’t – they’re the best available. We’re using the HF design for our Porsche Carrera 997 converter offerings. They are known for their effectiveness at catalyzing given the amount of flow they offer. This is how we add more sound and power without triggering check engine lights – or worse – having catalyst material blowing out of the rear of the car under abuse! You probably know about the HD design which is seen more commonly in performance applications – here are a few facts about the HD design:

  • The HD design uses premium triple foil winding for maximum integrity.
  • The brazing stripe (indent around the outside of the catalytic converter) is an extra feature in the interest of durability – it prevents the core from moving or experiencing any damage from sustained high horsepower abuse.
  • They are directional for increased efficiency and effectiveness.

For the 997 Carrera application, the HF variant is perfectly suitable given that their downstream location is not subject to extreme exhaust gas pulses. They are perfectly capable of handling the power level, and the cost is significantly less, which lets us offer you a quality product at a greater value. Newer vehicles are also more sensitive when it comes to emissions necessitating the improved efficiency of the HD design. For these reasons, we are using them as our replacement catalytic converter solution. We started testing with a non-x pipe split bank design as you see installed on the vehicle above.

Here’s what our Porsche Carrera 997 catalytic converters sound like with the stock mufflers:


We’ve done sidebyside sound comparisons with our design and an X-pipe in the design and found that adding an x-pipe lowers volume slightly and cuts down on deeper frequencies. Separating the banks adds more volume and more character for a deeper and fuller exhaust note. A hint of rasp presents itself, but it’s not excessive. A catless setup has not been tested at this time. We’re evaluating the best way to cut down on rasp and excessive volume from eliminating catalytic converters through resonators or Helmholtz resonators.


Our Competition Porsche Headers are a straightforward install – perfect fit! The large diameter piping and smooth flow path will optimize exhaust flow coming out of the engine. The 997 Carrera does not have catalytic converters in the headers, so this a mod that we consider icing on the cake.


Our initial Porsche custom exhaust tip offering for the 997 Carrera will be dual wall carbon fiber / stainless steel tips. We have our eye on polished chrome and custom built single wall tips as well.

As of now, our development car has been picked up, and we look forward to another round of product optimization on a second car shortly. Your feedback and comments would be most appreciated to steer us in the direction that brings the products you want to the market. Thank you for reading!

Contact us at for early adopter info and details

>>Porsche 997.1 Carrera Product Pages<<

Questions? Comments? Let us know!

– Mike Spock / Marketing Manager