AA Equal Length Midpipe - BMW M3, M4 F80/F82

The delivery time for products in stock is 1-3 business days.

If the product is not in stock and it is a pre order product, the average delivery time is 5-21 business days. If the product has a longer delivery time than previously announced, we will be in touch.

Terms for product returns:

• You must return the ordered products within 14 days of receiving
• The products must be unused and without damages
• Commission fee for handling returns is 21,90€
• For product returns, the customer is in charge of the return costs. Only door to door service (Express)
• Shipping costs are not refunded

For international orders (outside of Europe) sales are final and non-refundable. Once an order is placed, it cannot be canceled or returned. By placing an order, you acknowledge and agree to these terms.

Return address: QT Parts, Vasarakatu 8B, 37150 Nokia, Finland.

Pre order / made-to-order products

If the product you have ordered is a pre order or made-to-order item, it is not subject to the 14-day right of withdrawal or return under consumer protection laws, as the product is manufactured or sourced specifically based on the customer’s individual order.

If you wish to cancel your order before receiving the product, we will refund 50% of the total order amount.

This condition applies to the following product categories:

• Suspension
• Engine Tuning
• Engine Parts
• Exhaust Systems
• Fueling
• Turbochargers/superchargers
• Drivetrain
• ECE-approved Downpipes

All of the above products are manufactured or sourced individually based on the customer’s order, and therefore cannot be returned after delivery, unless the product has a manufacturing or material defect.

In the event of such a defect, the standard liability for defects as provided by consumer protection legislation shall apply.

Active Autowerke has been an industry leader in engineering high quality BMW performance products for over 39 years. Dedicated to improving the enjoyment of your driving machine with the highest quality products, Active Autowerke has been recognized as the leading BMW innovator. Our philosophy is 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, patent pending in UK and EU) 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 additional 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.