DESCRIPTION
Active Autowerke has been an industry leader in engineering high-quality BMW performance products for over 39 years. Dedicated to enhancing the driving experience with the highest quality products, Active Autowerke has been recognized as the leader in BMW innovation. Our philosophy of developing refined BMW performance parts and making them available to the wider BMW community is exemplified by our latest 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 pending), the alternative to our world-renowned F8X single mid-pipe.
An inline 6-cylinder engine naturally has evenly spaced exhaust pulses, resulting in a smoother, more sonorous sound. However, the S55's twin-turbo setup, while producing extra power, created a sound more like two independent inline 3s competing for loudness than the guttural roar one might expect. The nearly 1.5-foot variation in length between the front and rear downpipes creates unevenly spaced pulses, so that when they merge in any form of crossover system—whether stock, X-pipes, dual X-pipes, single mid-pipes, or rear-section solutions—sound waves travel at the same rate as they exit the system, these crossover sections simply create a higher-pitched sound, resulting in the annoying noise some have dubbed a "weed-eater" sound. Current systems allow dynos to merge unevenly pulsed sounds and after much research and testing (by 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 the space variance behind the differential housing, one complaint being the inability to retain existing rear exhaust systems. Active Autowerke decided to leverage its expertise, having already developed a single mid-pipe system for M-series cars, and dedicated its R&D resources to developing the mid-pipe solution you see here. Our R&D team explored ways to achieve this, and while compensating for the difference in the rear section of the exhaust seemed the most logical approach, it would require a completely new rear exhaust system, and we were aware that many BMW owners wouldn't like that option. So, we considered adding length to the passenger-side mid-section and creating a new crossover section to produce an exhaust note unlike anything we've ever heard before—the "S55 sound." The use of a patented solution of a crossover with sinusoidal pipes allowed us to correct the variance of the downpipe length before mixing the sounds giving the expected exhaust notes of a 6-cylinder sports car.
The Active Autowerke F8X Equal Length Mid Pipe was specifically designed to create equal-length exhaust pipes that accommodate the difference between the front and rear downpipes of the F80 M3 and F82 M4 before combining them into an X-pipe, creating an exhaust note distinct from the standard "S55 sound." Designed for a precise fit on the F80 M3 and F82 M4, the difference in sound with this mid pipe will be noticeable the first time you open the throttle!
PLEASE NOTE THAT IT IS STRONGLY RECOMMENDED THAT CARS WITH CAT-FREE (STRAIGHT) DOWNPIPES USE THE RESONATOR OPTION FOR THE EQUALLY LENGTH INTERMEDIATE PIPE.
Installation Guide
KEY FEATURES
- Lighter weight than the factory system
- Faster turbo coil
- Increased power in the low and mid ranges
- The equal-length design eliminates the pulsating sound caused by downpipes of unequal lengths.
APPLICATIONS
- F8X BMW M3 and M4
Active Autowerke has been an industry leader in engineering high-quality BMW performance products for over 39 years. Dedicated to enhancing the driving experience with the highest quality products, Active Autowerke has been recognized as the leader in BMW innovation. Our philosophy of developing refined BMW performance parts and making them available to the wider BMW community is exemplified by our latest 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 pending), the alternative to our world-renowned F8X single mid-pipe.
An inline 6-cylinder engine naturally has evenly spaced exhaust pulses, resulting in a smoother, more sonorous sound. However, the S55's twin-turbo setup, while producing extra power, created a sound more like two independent inline 3s competing for loudness than the guttural roar one might expect. The nearly 1.5-foot variation in length between the front and rear downpipes creates unevenly spaced pulses, so that when they merge in any form of crossover system—whether stock, X-pipes, dual X-pipes, single mid-pipes, or rear-section solutions—sound waves travel at the same rate as they exit the system, these crossover sections simply create a higher-pitched sound, resulting in the annoying noise some have dubbed a "weed-eater" sound. Current systems allow dynos to merge unevenly pulsed sounds and after much research and testing (by 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 the space variance behind the differential housing, one complaint being the inability to retain existing rear exhaust systems. Active Autowerke decided to leverage its expertise, having already developed a single mid-pipe system for M-series cars, and dedicated its R&D resources to developing the mid-pipe solution you see here. Our R&D team explored ways to achieve this, and while compensating for the difference in the rear section of the exhaust seemed the most logical approach, it would require a completely new rear exhaust system, and we were aware that many BMW owners wouldn't like that option. So, we considered adding length to the passenger-side mid-section and creating a new crossover section to produce an exhaust note unlike anything we've ever heard before—the "S55 sound." The use of a patented solution of a crossover with sinusoidal pipes allowed us to correct the variance of the downpipe length before mixing the sounds giving the expected exhaust notes of a 6-cylinder sports car.
The Active Autowerke F8X Equal Length Mid Pipe was specifically designed to create equal-length exhaust pipes that accommodate the difference between the front and rear downpipes of the F80 M3 and F82 M4 before combining them into an X-pipe, creating an exhaust note distinct from the standard "S55 sound." Designed for a precise fit on the F80 M3 and F82 M4, the difference in sound with this mid pipe will be noticeable the first time you open the throttle!
PLEASE NOTE THAT IT IS STRONGLY RECOMMENDED THAT CARS WITH CAT-FREE (STRAIGHT) DOWNPIPES USE THE RESONATOR OPTION FOR THE EQUALLY LENGTH INTERMEDIATE PIPE.
Installation Guide
KEY FEATURES
- Lighter weight than the factory system
- Faster turbo coil
- Increased power in the low and mid ranges
- The equal-length design eliminates the pulsating sound caused by downpipes of unequal lengths.
APPLICATIONS
- F8X BMW M3 and M4