It seems like BMW may have slightly dropped the ball on post E39 M5 stock V8 exhaust sound, including non-M-Powered V8s. As much as I dread saying this, it is true. Stock Mercedes-Benz AMG V8 engines sound better than stock BMW M-Powered V8 engines. AMG has even figured out a way to make turbo-charged engines sound as good, if not better than naturally aspirated V8s.

An X-pipe on BMW V8 engines will improve exhaust sound. But before we get carried away, it’s only fair to mention that a good aftermarket exhaust system bolted on the high revving S65 4.0-liter E90/92 M3, may put any AMG sourced exhaust system to shame, making it comparable to the sound of a Ferrari 458.

“Xpipes and Ypipes: Usually mounted after the catalytic converters, replacing the stock resonator(s) in most cases. They provide increased exhaust flow and sound benefits, especially on naturally aspirated engines. Xpipes are used on true dual exhaust systems, while Ypipes fit on single exhaust system thats branches out to dual exit exhaust pipes. Xpipes and Ypipes come in two forms, direct fit, or universal. The later require cutting and welding of the stock exhaust.”

X-pipes and V8 powered vehicles go hand in hand, even on relatively small-displacement high-output naturally aspirated or twin-turbo charged power plants. Considering the most recent BMWs equipped with 8 cylinder engines, an X-pipe mod is the easiest, least expensive, and best sounding exhaust modification. Leaving virtually no cabin drone, a good thing for a luxury sport car occupants . We’ve all heard tons of complaints about the new BMW M5 F10’s in-cabin fake engine noise. Due to BMWs extensive use of sound-deadening material throughout the vehicle architecture, a pre-recorded engine/exhaust sound track is played through the speaker system, in an effort to enhance the driving experience. Smart idea, but a big No-No for M5 enthusiast. Therefore, it only makes sense to throw out the heavy-useless OEM exhaust system, replacing it with a full exhaust, catback, or at least an X-pipe.

Background: X-pipes were commonly used on V8 muscle cars… Then in the nineties, refined fabrication tech developments made it possible to build a specific exhaust pipe, which instead of linking through a balance pipe at a severe ninety degree angle, it unified the two sides of tubing, creating exhaust flow in one uniform direction. Fast forward to today, X-pipes are widely available as stand alone items, part of a catback exhaust, and integrated within high performance, light weight, and even cat-less direct bolt-on exhaust systems. Alternatively, street legal aftermarket exhaust systems featuring improved flow downpipes, high flow cats,  X-pipes, and sport mufflers are widely available for BMW cars and SAVs. Replacing the resonators with an X-pipe would deepen the exhaust note, without making it an unbearable daily driver for drivers and passengers alike.

(to say the least, if not a Catback or a Full Exhaust System)
3 -Series E9X Chassis: S65 4.0 liter naturally aspirated V8 engine: E90 BMW M3 Sedan, E92 BMW M3 Coupe, and E93 BMW M3 Convertible
5-Series F1X & E6X Chassis: S63Tu 4.4 liter TwinPower Turbo V8 engine: F10 BMW M5 Sedan, F11 BMW M5 Sport Wagon
S63 4.4 liter TwinPower Turbo V8 engine: F10 BMW 550i, F10 550i xDrive Sedan, F11 550i Wagon, and F07 550i GT
N62 4.4 liter & 4.8 liter naturally aspirated V8 engine: E60 545i, E60 550i
5 & 6-Series E7X Chassis (SAV): S63 4.4 liter TwinPower Turbo V8 engine: E70 X5 M, E71 X6 M
N63 4.4 liter TwinPower Turbo V8 engine: E70 X5 550ixDrive, E71 X6 550ixDrive
N62 4.4 liter & 4.8 liter naturally aspirated V8 engine: E70 X5 4.8
6-Series F1X Chassis: N63 4.4 liter TwinPower Turbo V8 engine: F12 650i Coupe, F13 650i Convertible, and 650i Gran Coupe sedan
N62 4.4 liter & 4.8 liter naturally aspirated V8 engine: E63 645i Coupe, E64 645i Convertible, E63 650i Coupe, and E64 6450 Convertible
7-Series F0X & E6X Chassis: N63 4.4 liter TwinPower Turbo V8 engine: F01 750i, F02 750Li, with or without xDrive.
N62 4.4 liter & 4.8 liter naturally aspirated V8 engine: E65 745i and 750i, E66 745Li, E66 750Li and 760Li.

An X-pipe mod can be done alone, included in an aftermarket cat-back exhaust system, or packaged within a full exhaust system. Why should you consider an X-pipe? Slightly louder, deeper and healthier, yet drone free exhaust sound. Slight increase in performance and fuel economy, with the least negative effect on your bank account.

A bunch of aftermarket BMW specific X-pipes are available, as well as universal X-pipes with similar diameter tubing as the OEM BMW exhaust system. Therefore, installation should be a breeze given that any fairly experienced local muffler shop could easily do the installation for less than $200 USD. Unless you are the DIY type of person, well-equipped to cut the resonator off, welding on the X-pipe after properly aligning the tailpipes with the bumper.  Regardless of the installation method, the outcome is definitely worth the effort.

Again, sound is the greatest benefit of X-pipes, beyond any performance gains. Future CO2 emission level limits and CAFE regulations will continue to force car makers like BMW to engineer smaller-displacement forced-induction engines, further reducing the ability to easily extract a great exhaust growl. With that in mind,  just get your hands on an E60 M5 and enjoy listening to its F1-sounding naturally-aspirated V10.

Source: Exhaust System Parts Explained


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