DEVELOPMENT AND TESTING: We wanted to get as aggressive as possible while minimizing drone – greater volume with a greater amount of pops and burbles on deceleration. Support for high power was another consideration – necessitating 3″ tubing. We experimented with adding a mixing chamber into our X-pipe design. Analysis in 3D CAD software showed a general increase in velocity gained downstream of the mixing chamber across a band of measured pressure and temperature levels. This produces optimal flow characteristics, reduced backpressure for higher HP, and enhances the sound quality of the system.The 997 Turbo is very prone to drone when you start to uncork it. For our Sport variant, HJS HD 200 cell catalysts do a great job at keeping the sound level and quality at a reserved and refined tone - definitely daily driveable. Once we removed the cats for a Competition version, drone was present in the 2,000 - 3,000 RPM range by a fair amount. We tested out different resonator types, amounts (0, 2, and 4) and found best results with 4 resonators. We even tried to use rubber isolators to reduce drone but the effect was not noticeable.


We pushed on and added helmholtz resonators using calculations to specifically target droning further in the lower RPM's where it is most pronounced. They proved to be quite effective - greatly cutting down on drone as intended. The final result is a car that has a great tone with an acceptable level of in cabin presence - drone is still present at low RPM to a degree but this IS a catless race exhaust.




CONSTRUCTION: Each exhaust is made from mandrel bent T304L 3″ .065″ wall stainless steel tubing, straight through race resonators with a full metal packing design for maximum durability, and laser cut brackets for perfect fitment. Choose from several hand finished tip options to get the look that suits your 991 the best – or reuse your factory tips. Mikalor Supra Heavy-Duty Clamps are included to securely hold our tips onto the system.


HJS CATALYSTS: The highest quality catalytic converters available, known for their industry leading flow and durability. They are efficient enough to meet strict EURO 4 emission standards while still allowing for an increase in flow – all without a check engine light. The HD design uses premium triple foil winding for maximum strength. The brazing stripe is an extra feature in the interest of durability – it prevents the core from moving or experiencing any damage from sustained high horsepower abuse. We use a large and appropriately sized catalyst to allow for maximum gains – no compromises here!



WEIGHTS: The Competition exhaustweighs approximately 16.2 lbs / 7.3 kg less than factory exhaust components (28.8 lbs vs 45 lbs) while the Sport exhaust weighs approximately 10.8 lbs / 4.9 kg less than factory exhaust components (34.2 lbs vs 45 lbs).

CHECK ENGINE LIGHT?: Expect no CEL with our catted Sport X-Pipe Exhaust System. Catless, most likely, but chances can be reduced with our catted O2 spacers.





LIFETIME WARRANTY: Enjoy your Soul exhaust components with confidence on both the street and track as they are covered by our Lifetime Warranty! Our team will quickly work with you to resolve any issues or answer any questions that you may have.

Very nice touch on the resonator. I had a competitors X-pipe exhaust with with 200 cell cats and got rid of it because of the drone. Annoying as hell. Great work! Good luck with sales.

Really nice lookIng/sounding system.

can you pm me pricing.