The BCS Valveless Turbo-back (with 100 Cell Cat) sport exhaust for the M135i N55 (Electronic Waste Gate Variant), provides a perfectly balanced sports tone both externally and internally above the stock exhaust note when the car is running off boost (Cruising and driving sedately). However, as you are no doubt already aware if you are looking to create the best possible audible thrill... 

Our BCS Valveless system offers a unique perspective on exhaust technology, Incorporating Acoustic tuning into our systems to provide the driver with two distinct natures. When the car is under low load or cruising the sound is at once uplifted and noticeable yet controller and non intrusive, However when the car is driven aggressively under high load the acoustic set ups within the silencers alter the note, becoming a purposeful and redefined true essence of the M135i. All of which are under he complete control of your right foot, therefore, you determine the sound minute to minute depending on your particular driving requirements. By using this unique interaction, the driver cease to become desensitized in the way you would with a non-variable sound, leaving you looking for more time behind the wheel...

The system has a greater audible volume than the cat back offering, however, with careful design and development we have created a system that ensures that any unwanted in-car frequencies are removed, leaving you with a perfect drone-free experience, with our characterful pop & burble free-revving sound.

As with virtually all of the N55 engined vehicles, there is very little performance gain to be had from the cat-back system on its own, due to the incredibly restrictive downpipe and  OEM cat. However, by opting for our unique downpipe and high flow cat the power potential will massively increase, firstly with an initial 22bhp kinetic, and then once mapped the N55 Engine can achieve in excess of 450 bhp with our full turbo-back system and 100 Cell Sports Cat. 

Is my car the Electronic Waste Gate variant, or the Pneumatic Waste Gate variant?

If you look to the left side of the engine, next to the water header tank, you should see the following configuration as shown below.

If you cannot see the empty bracket with the bolt protruding as shown above, then you have the configuration below which features on the pneumatic wastegate variant earlier model.

If this is the case please navigate back to our model selection and select the PWG variant.