Active Autowerke Gen 2 Equal Length Mid Pipe - BMW / F8X / M3 / M4

After extensive research and development, ACTIVE AUTOWERKE has announced GEN 2 of our EL midpipes. We worked with our factories to create specially developed RESONATORS that remove rasp from the exhaust tones with minimal change in the volume of the sound. A side benefit is that this also resulted in a reduction in the "2k buzzing" annoying to some BMW owners. GEN 2 replaces the existing F80 M3 and M4 EL midpipe which is no longer available for sale, so Active Autowerke has developed an upgrade program for EL existing owners who want to take advantage of this improvement. THIS PROGRAM IS VALID FOR ORIGINAL PURCHASERS OF EL MIDPIPES ONLY - proof of purchase required. Contact Active Autowerke for details on this program.

We are recommending to owners of cars with after-market downpipes to use the resonated version but we have only tested with stock and Active downpipes and stock and Active rear exhausts.

 With stock downpipes, there is some small rasp so you may also want to opt for the resonated version. However if you have the MPE or CS exhaust, you should strongly consider using the resonated version.

Includes Active F-brace and $90 fixed price shipping in lower 48 states.

WE DO NOT GUARANTEE RESULTS OR FITMENT WITH OTHER MAKES OF REAR EXHAUSTS. 

**This product is a part of the Active Autowerke Motorsport Collection. It is for RACE and OFF-ROAD USE ONLY! 

***Before your order ships you MUST check the Off Road Use Only Waiver***

Active Autowerke has been an industry leader in engineering high quality BMW performance products for over 41 years. Dedicated to improving enjoyment of your driving machine with the highest quality products, Active Autowerke has been recognized as the leading BMW innovator. Our philosophy on developing refined BMW performance parts and making them available to the larger BMW community is highlighted by our most recent R&D program focused on improving the sound of the S55 exhaust. This R&D has resulted in the development of the Active Autowerke F80 M3 and F82 M4 equal length mid-pipe (US Patent 11248511, UK and EU patent 3882441) the other option to our world famous F8X single mid-pipe.

An inline 6 engine naturally has an evenly spaced exhaust pulse which results in a more smooth and full sounding noise. However, the twin turbo setup of the S55 engine while producing addition power has created a sound which sounds more like 2 independent inline 3's competing for noise than the throaty sound one would expect. The variance between the lengths of the front and rear down-pipes of almost a foot and a half creates unevenly spaced pulses so that when the merge in any form of crossover system whether stock, x-pipes, double x-pipes, single mid-pipe or rear-section solutions. Since the sound waves are moving at the same rate when they exit the system, these crossover sections are simply creating a higher pitched sound resulting in the annoying sound some have referred to as a weed eater sound. The current systems allow the banks to merge unequally pulsed sounds and after much research and testing (from many BMW experts) it was determined that equalizing the length of the exhaust pipes before mixing was a solution to this sound problem.

Initial exhaust solutions focused on correcting this variance in the space behind the differential housing with one complaint being the inability to keep existing rear exhaust systems. Active Autowerke decided to leverage our expertise in having already developed a single mid-pipe system for the F-series M cars and devoted our R&D resources into developing the mid-pipe solution which you see here. Our R&D looked at the ways this could be done and while making up the difference in the rear section of the exhaust seemed like the most logical place, it would require a brand new rear exhaust system and we were aware that many BMW owners would not like this option. So we looked at adding length to the passenger side midpipe section and creating a new crossover section to create an exhaust note that's never been akin to the "S55 sound". Using a patented solution of a crossover with sinusoidal pipes allowed us to correct the downpipe length variance before mixing the sounds giving the expected 6 cylinder sports car exhaust notes.

The Active Autowerke F8X Equal Length Mid Pipe was specifically designed to create equal length exhaust pipes adjusting for the difference between the front and rear banks of the F80 M3 and F82 M4 down pipes before mixing in an X-pipe and creating an exhaust note different from the normal "S55 sound". Engineered for an exact fit on both the F80 M3 and F82 M4, the difference in sound with this mid pipe will be noticeable the first time with an open throttle!

PLEASE NOTE: IT IS STRONGLY RECOMMENDED THAT CARS WITH CATLESS (STRAIGHT-THROUGH) DOWNPIPES USE THE RESONATOR OPTION FOR THE EQUAL LENGTH MIDPIPE.

Key Features

• Lighter weight than factory system
• Quicker turbo spool
• Increased low end and mid-range power
• Equal length design eliminates the pulsing sound caused by the unequal length down pipes