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Description
Dinan Free Flow Axle-Back Exhaust for 2020-2024 BMW M340i/M440i D660-0085-BLKDinan Free Flow Axle Back Exhaust 2020 2024 BMW M340i M440i Quad exhaust tips have been a signature feature of the most powerful letter in the automotive sphere for quite some time. It is a hallmark of the brand that Dinan has long embraced, limiting its own quad tip usage to those M cars that already sported like tip quantity from the factory. That is? until now with the release of the Dinan axle back exhaust system for the G20 M340i and G2x M440i.
Dinan Free Flow Axle-Back Exhaust - 2020-2024 BMW M340i/M440i
Quad exhaust tips have been a signature feature of the most powerful letter in the automotive sphere for quite some time. It is a hallmark of the brand that Dinan has long embraced, limiting its own quad tip usage to those M cars that already sported like tip quantity from the factory. That is? until now with the release of the Dinan axle back exhaust system for the G20 M340i and G2x M440i.
Features:
- More Power: +?6 HP @ 6600 RPM, + 5 LB-FT @ 6600 RPM
- Enjoyably louder, sportier sound
- Quad 4" diameter clamp-on, double-walled, ceramic black and laser engraved exhaust tips
- 100% 304 stainless steel construction
- Larger diameter piping for increased flow (76mm vs 70mm)
- 4 lbs lighter than the stock system
- Stock exhaust valve actuator reused and another valve/actuator added to the opposing side promoting even flow regardless of valve position
- Computer controlled exhaust valves are retained and limit noise during low speed driving and open fully during high-load conditions
- Twin exhaust valves are a whopping 76mm diameter, making them 30% less restrictive than the OE valves
- Easy bolt-on installation with included mounting hardware
Specs:
| Brand | Dinan |
|---|---|
| Dinan Point Value | 3 |
| Emission Code | 5 |
| Height | 10 |
| Labor Time (Hours) | 2.5 |
| Length | 54 |
| Max HP Gain | 6 @ 6600 RPM |
| Max Torque (lb-ft) Gain | 5 @ 6600 RPM |
| Product Type | Axle-Back Exhaust |
| Sale Category | Exhaust |
| Tip Finish | Black Ceramic Coated |
| Warning | California Proposition 65 |
| Weight | 68 |
| Width | 29 |
Application:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2020-2024 | BMW | M340i | Base |
| 2020-2024 | BMW | M340i xDrive | Base |
| 2021-2024 | BMW | M440i xDrive | Base |
| 2021-2024 | BMW | M440i | Base |
| 2022-2024 | BMW | M440i | Base |
| 2022-2024 | BMW | M440i xDrive Gran Coupe | Base |
| 2022-2024 | BMW | M440i Gran Coupe | Base |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.6 ★★★★★
Based on 876 reviews
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Product Reviews
★★★★★ 3
Generally happy
Style: Tech Pack 28 sqft, Style: Tech Pack 28 sqft
Much thinner than I expected, but installation went better than I'd thought it would. Needed to line the interior of the engine cover of a Ford E450 RV. Tried nitrile gloves, but they stuck to the material so did it bare handed. Cut easily with a fresh razor blade. Pressed in place with a plastic putty knife. We'll see the effectiveness on the next trip.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 3, 2025
★★★★★ 5
Makes For Quiet Rides
Model: 10 SqFt(0.95 SqM)
Comparable quality and performance to name brand competitor. It sticks on strong, easy to apply, and does make a difference in sound reduction. Turn your hollow shell sounding vehicle panels into solid sounding walls.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 15, 2026
★★★★★ 5
Must for subwoofers. True 2mm spec. High quality.
Model: 36 SqFt(3.4 SqM), Model: 36 SqFt(3.4 SqM)
Let me start of by saying WOW! This made a huge difference in the SQ of my L7S pushing 930w rms. Before I had major rattles in my 2020 Honda Civic SI. Taking the time to do this to my trunk and Lid made me realize just how loud my subwoofer actually is. It literally eliminated the rattles throughout my whole car. I still plan on doing this to my doors and rear deck but once I upgrade the speakers. I still have half of the box just doing the trunk and lid so 1 box of 36sf will be enough for most of the areas that need to get done. You may need a little more overall. This is true 2mm spec. Very sticky and easy to apply. It just take time to finish the work correctly and roll it down. It is not as heavy as I thought it was going to be. The size of the sheets are perfect for what you need to do. The value is on point for the quality. It does not rip very easily but you can cut it to size without any problems. Again, This is a must buy for anyone who is pushing 1000w rms or more.
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Reviewed in the United States on November 29, 2025
★★★★★ 5
Quality product you
Model: 18 SqFt(1.7 SqM), Model: 18 SqFt(1.7 SqM)
Summary: Great quality product, priced right. Cuts and installs easy-follow the instructions people!! PRO TIP-you don’t need to cover every square inch. OVERKILL!! Think about it-when a bell rings you could put your fingers on the edge and silence it right? Same rules apply here. A strip or square will isolate the vibration and notice when placed correctly— knock on the surface and see what vibrates or what part makes the loudest drowning and that’s a good clue of where you should put a piece of this…unless you’re trying to use it for temperature insulation no need to go ape on it. If you look at the bottom of a stainless steel sink, it’s got a stripe or a small sticker of insulation that keeps it from rattling. You can do that here. What’s important to note is the instruction specifically say use a roller to roll the ribs out until it’s smooth that way you’ve got maximum adhesion. I see a lot of pictures and videos from people that finished their install and didn’t follow this simple instruction. It makes sure that it’s stuck down before you put all your paneling and carpet back in and it’s a small step with a cheap wooden roller it’s easy. I’ll say the installation with this product is a breeze. You can use sharp scissors or a blade. It does get gummy after a while, and you may need to clean off your blade or your scissors, but it cuts very well and the ribs make it easy to size in space the thickness is fantastic and the backing paper comes off quite easily. I’ve done lots of installations with Graphics emblems you name it and this product is very easy to use and represents good value.
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Reviewed in the United States on March 30, 2026
★★★★★ 5
Good stuff !
Model: 36 SqFt(3.4 SqM), Model: 36 SqFt(3.4 SqM)
This is an excellent product. Easily moldable, cuttable with good scissors or razor knife, very sticky, works great.
This pack was enough to do all 4 doors on a crew max truck, and I went wild on the fronts. I used 9 peices on each rear door which was just enough, and the rest on the fronts. I doubled up layers and even used some on the back of the door panels. If you follow the instructions and dont go wild you might even have extra left over.
It works just like you would imagine. Without doing the entire cab there will still be road noise but this helped noise, better audio, no buzzing door panels, terrific improvement.
It is kind of heavy, so extra weight is added to truck, but that really isnt a bad thing. It is noticable but in a good way.
Get it. Use it.
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Reviewed in the United States on March 20, 2026
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