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 Delete, 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 X-Pipe Muffler Delete 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, if you don't have the factory PSE Exhaust the installation without the purchase of our side mufflers and exhaust tips.
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 or purchase the optional NHP Exhaust Tips, with the sport exhaust button you don't need to install our solenoid and vacuum line kit.
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.
The 991 Models sound ok from factory, when they are equipped with the PSE they sound pretty good, but if you're looking for a much better sound and more "pops and crackles" this is for you. The NHP 991 Center X-Pipe sounds amazing. It's almost impossible for a Sports Car type of guy to dislike the sound our pipe produces. With the valves closed it delivers a nice sound taht's expected from a sports car of that caliber and will make your long drives or drives with the wife acceptable, it sounds way better then stock even with the valves closed. When you open the valves its a whole different ball game you get an agressive sounding exhaust with lots of poping sounds like a true race car.
The exhaust flow from the headers enter a 2.75" pipe that leads to resonators and converts to a 2.5" pipe at the X-Pipe , the X-Pipe is a true X-pipe independant from each other (Left+Right). We use High Quality SS-304 thick 14 gauge Stainless Steel to eliminate possibilities of cabin drone. This 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 availabilty, but considering the design and nature of X-Pipe design 15HP range is a realistic estimate.
The NHP 991 Exhaust X-Pipe with valves is the way to go, get yours today.
For those of you who prefer a less louder exhaust with valves closed please check out our Porsche 991 /991S / 991C4S Center Muffler with Sound Valves