Product Fitment : 991 / 991 S / 991 C4S
For Base 991 with 3.4L Only you must have the factory PSE Exhaust in order to install the X-Pipe Muffler, if you don't have the PSE exhaust on your 3.4L you will need to purchase our side mufflers and exhaust tips to complete this setup.
The NHP Porsche 991 Center Muffler with Sound Valves is a plug n play installation no modification is necessary to install this exhaust. But in order to install this exhaust you must acknowledge the following:
991 3.4L If you own a Base 991 3.4L Model, the installation is not possible for now, once we finsih development of the side mufflers it will be a possibility to install it on a Base Model along with our side muffler and exhaust tips, once again you must have the factory PSE exhaust for this to work on a 3.4L engine.
991 S / C4S with Factory PSE If you own the 991 3.8L Model you can install this exhaust if you car was equipped from factory with the PSE Exhaust and fitted with the Porsche Manual Exhaust Button this will simply result in a Plug N Play installation with no additional parts needed for the installation, you could re-use your factory tips are purchase the optional NHP Exhaust Tips.
991 S / C4S without factory PSE If you own the 991 3.8L Model without the factory PSE Exhaust the installation will require the "Valve Actuator Kit" that will enable you to control the sound of the exhaust, it is available via FOB Remote or simply with a conventional ON/OFF toggle switch that can be mounted at in your preferred location in the dash area. See the last 4 pictures, if you chose the to have the remote kit you will get to beautiful Key Fobs made of aluminum with black back plastic casing, if you chose to install the toggle switch ON/OFF in cabin this switch can be installed at your preferred location with 3M double sided tape.
If you want your 991 to sound like a real sports car the NHP Center Muffler with valves is the way to go. With the valves off you get a nice clean sports sound with no cabin drone or resonance making this ideal for long drives and regular daily driving, when you open the valves the sound is phenomenal with a much more aggressive touch to it. Lots of crackle and pop sounds coming out of this exhaust giving you the race car feeling...
This design is very similar to the factory PSE exhaust from Porsche , If you heard a factory 991 with PSE exhaust from Porsche our sound is very similar but approx 15% louder when the valves are open and you get full 100% open valves when installed with our control switch, we guarantee you a perfect fit and a high quality product.
Our exhaust is made with 2 Mufflers and is based on X-Pipe design, the exhaust flow from the headers enter a 2.75" pipe when the valves are closed the exhaust travels through the center mufflers and the side mufflers as well, when the valves are open the exhaust travels via the X-Pipe joint and bypasses the side mufflers exiting directly to the exhaust tips. Our Center muffler pipe should easily increase HP to approx 15+ HP however we haven't had a chance to dyno a 991 at this time due to limited availability.
The pictures below show the "non-polished" version of our Center Muffler.
Full installation instructions will be available with your purchase.