BMW Catback Exhaust Systems

Looking to elevate the acoustics of your X3 M40i / X4 M40i with an exhaust system that not only offers a much-improved sound while retaining the flexibility associated with valves, but also raises the eye appeal beyond the mundane? Look no further than the Dinan valved cat-back to meet all your needs… and then some! 

The full cat-back requires no cutting and utilizes factory mounting locations that allow the Dinan exhaust system to be a straightforward and painless install. Fabricated from brushed 100% T304 stainless steel, TIG welded, and free of hydroformed pipe, the upgraded system is also a marked improvement from its predecessor - both in terms of material/construction as well as in overall looks. The most glaring change being the replacement of the OEM dual slip tips in favor of an M-inspired quad tip configuration. Despite the limited room, Dinan was determined to offer four individually functioning pathways/tips and not lessen the representation with Y-tips or other gimmickry.  The result is a proper quad setup furnished with cavity covering 3.75-inch (95mm) tips in either black ceramic or polished stainless ensuring the system can be appreciated even before it is heard.

While looks are important, the auditory advantages are what any enthusiast is truly after with an exhaust system, and the Dinan offering for the G01/G02 M40i platform delivers in spades. For not only aural enhancement via the elimination of the central collector/resonator, but also weight savings and simplicity. The stock single-to-dual pipe setup has been abandoned in favor of an enlarged, straight, unrestricted, and freer-flowing single pipe system. This pathway feeds into a Helmholtz-equipped muffler that limits frequencies associated with drone, as well as assists in altering the overall tone of the setup to deliver the signature low Dinan rumble. The no-nonsense design allows versatility in volume levels with the retained factory valve functionality. Go from refined when cruising (low RPM’s) to rowdy when in it (high RPM’s), with ease. Or better yet, pair the system with an exhaust valve remote and have full control of elevating or reducing the sound! When open, the system behaves as a straight pipe solution that promotes maximum flow and volume for an exhilarating and forceful chorus. When the valve is closed, however, exhaust gases are wholly redirected through the muffler and emit more tempered vocals acceptable for even the most sensitive ears. It is the perfect blend of civility when cruising or the full spectrum of auditory delight when in the throttle. No matter the situation, the Dinan valved cat-back exhaust system is the answer for the discerning enthusiast looking for sound without sacrifice.

Features:

Maximum gains of +6 HP and +5 lb-ft of torque

Enjoyably louder, sportier sound w/ a delightful octave drop

Drone abatement technologies used to reduce cabin resonance

Quad 3.75-inch (95mm) double-walled, polished (or black ceramic coated) clamp-on tips with laser engraved Dinan logo

Larger diameter piping for increased flow (83mm vs. 80mm) 

Factory resonator/collector removed for increased volume

7-pounds lighter than the stock system (60-pounds vs. Dinan: 53-pounds)

100% 304 Stainless Steel construction

Factory valve functionality retained; refined or rowdy from the same exhaust

Direct bolt-on w/ no cutting or welding required

Factory-like fitment with included mounting hardware and valve componentry for both pre-LCI and LCI compatibility