​BMW M3/M4 Exhaust – Let’s Discuss The Different Components

[mike@x-ph.com]

I always get questions from forum users about the different components that need to be changed in order to achieve desired exhaust tone.

I tried my best to simplify this task and explain what kind of results are to be expected when changing any of these exhaust parts.

Hopefully this helps newcomers looking to upgrade their BMW M3 / M4 exhaust.


Downpipes:

Stock downpipes have catalytic converters. In order to increase sound and power, you can replace stock DP with aftermarket catless or high flow catted downpipes. One thing to keep in mind is that aftermarket downpipes will not pass emission and will throw a CEL (even catted ones). You can hide the code by using a piggyback like the Burger Tuning JB4 stage 2 or a flash tune (Even after hiding the code, your car will fail emission test. Downpipes are not be used on street cars anywhere in the US).

Catless downpipes are louder than catted, offer more air flow and power. Only downside is fuel smell outside the car if it has been on idle for some time. Good news is that the M3/M4 comes with secondary cats so fuel smell is barely noticeable. Even though it is not a popular option, some choose to go with high flow catted to completely eliminate the smell.

Stock downpipes come with a flex fuel section to help with heat retention. Catless downpipes do not have this problem, but some aftermarket companies choose to keep the flex section for added reliability. Active Autowerke test results showed that flex section helped dampen downpipe vibration

Another option that helps with heat is ceramic coating. If you track your car often, it is recommended that you choose this option for best results. Different ceramic coatings are offered with Swain coating being the best.

Midpipes:

One problem with the stock exhaust is raspiness; M3/M4 is not one of the best sounding sports cars. Fortunately this problem can be fixed when replacing the stock midpipes with a single one. Another benefit of the single mid pipe is the extra power that Dynos are showing.

If you are not bothered by exhaust rasp and are looking for a more aggressive sound, most companies offer the dual midpipes for a louder more aggressive tone. Some think the dual midpipes are too loud when paired with an aggressive axle back or catless downpipe, fortunately aftermarket companies also offer a resonated option that will give you a more aggressive tone than a single midpipe but still be quieter than non-resonated dual pipes.

Rear Section:

Replacing the rear section will change the tone of your exhaust the most. Lots of options are available and they are all different. Active Autowerke offers a 3 muffler setup for the cleanest possible sound, paired with a single midpipe this exhaust will eliminate rasp completely. One downside to this exhaust is that it will not be as aggressive as other exhausts on the market.

If you are looking for a deep and aggressive sound, options like REMUS and Fabspeed are available to you. These exhausts will not be loud during casual driving but once you go wide open throttle, they will shine.

GThaus offers the Meisterschaft GT2 exhaust, this option is one of the most aggressive on the market. This kind of exhaust is for users looking for an eye catcher system.

Another factor to consider is weight. Although most aftermarket exhausts are lighter than stock, some companies take it a step further. Burger Tuning achieves this result by offering an all-aluminum exhaust. If you do not mind paying extra money for a lighter exhaust, you can get a titanium system like GTHaus Meisterschaft, Akrapovic or the M-performance exhaust


Exhaust Valves:

Stock exhaust comes with valves; it will control the sound level of your BMW M3 / M4 exhaust. Stock valves cannot be controlled by user (unless you purchase an exhaust flap module like the one BMS offers). Some aftermarket companies use the stock valves on their system; others give the user the ability to control these valves.

Tips:

Last but not least are the exhaust tips, stock tips are tiny and do not give the M3/M4 the aggressive look it deserves. All aftermarket exhausts are offered with upgraded tips and the different options are endless. Some companies also offer upgraded tips for the stock exhaust in case user decides to keep the rear section and just upgrade the look of the tips.

[Cajun1]

Thanks for posting this! I'm in the market for some type of exhaust sound improvement and this helps. If the Remus has a deeper sound compared to stock, I might take that direction.

[mike@x-ph.com]

Originally Posted by Cajun1

Thanks for posting this! I'm in the market for some type of exhaust sound improvement and this helps. If the Remus has a deeper sound compared to stock, I might take that direction.

REMUS has a deep and aggressive tone, one of my favorite choices for daily drivers

[FAST FRED]

Hi,
this is a perfect Segway for me to ask some questions. I am new to BMW and the M cars. I have a 16 M3 and I would like to do a mid -pipe and some kind of tuning. What do you recommend.
Fred

[mike@x-ph.com]

Originally Posted by FAST FRED

Hi,
this is a perfect Segway for me to ask some questions. I am new to BMW and the M cars. I have a 16 M3 and I would like to do a mid -pipe and some kind of tuning. What do you recommend.
Fred

Hi Fred,
happy to help.

What kind of sound are you looking for? Loud and aggressive or clean and rasp free?

[LOW4LYF]

Mid pipe only...

[FAST FRED]

Originally Posted by mike@x-ph.com

Hi Fred,
happy to help.

What kind of sound are you looking for? Loud and aggressive or clean and rasp free?

Looking for aggressive,
what about tuning ?
Thanks

[Xerxes480]

Great write up - thanks!

-X-

[mike@x-ph.com]

Originally Posted by FAST FRED

Looking for aggressive,
what about tuning ?
Thanks

I would do REMUS non-resonated


Are you thinking about adding downpipe, methanol, E85 or upgraded turbos in the future?

[mike@x-ph.com]

Originally Posted by Xerxes480

Great write up - thanks!

-X-

You are welcome

[Arcades]

Man, having to ship Akra Evo pipe sucks. :

Thanks for the write up

[FAST FRED]

Originally Posted by mike@x-ph.com

I would do REMUS non-resonated


Are you thinking about adding downpipe, methanol, E85 or upgraded turbos in the future?

No,
just want to keep it simple. Exhaust and a tune.
Thanks again.
Fred

[mike@x-ph.com]

Originally Posted by FAST FRED

No,
just want to keep it simple. Exhaust and a tune.
Thanks again.
Fred

Jb stage 1

[FAST FRED]

Originally Posted by mike@x-ph.com

Jb stage 1

Perfect !
Thanks

[G35POPPEDMYCHERRY]

great write up...still will be a hundred threads asking the same question, ah bimmerpost. but love the new excitement when someone get a new car and cracks out on modding

[Justin.AutoTalent]

Originally Posted by FAST FRED

Perfect !
Thanks

I might recommend bootmod3 and downpipes. You get more sound, keep the stock tone, add burbles, and more power!

[mike@x-ph.com]

Originally Posted by FAST FRED

Perfect !
Thanks

You are welcome

[mike@x-ph.com]

Originally Posted by G35POPPEDMYCHERRY

great write up...still will be a hundred threads asking the same question, ah bimmerpost. but love the new excitement when someone get a new car and cracks out on modding

Thank you

[Fabspeed Motorsport]

We offer a solution for all three components.

Starting off with our Primary Catbypass Downpipes.



Then moving on to our Secondary Catbypass X-Pipe. Our X-Pipe is unique compared to others in that our x-pipe is designed to reduce the rasp these engines tend to produce. Couple this with a factory MPE and you have a pretty aggressive setup.

And finally, our full Valvetronic Exhaust System. This is one of the most complex designed systems in our product line. Our double x-pipe design accentuates the perfect exhaust tone. This system works in conjunction with our Primary Catbypass Downpipes for ultimate sound and power.

PM me for more details!

[SoFlo335]

Would be nice to have links to the different manufacturers of each component

[klipse]

Those sound real good

[mike@x-ph.com]

Originally Posted by SoFlo335

Would be nice to have links to the different manufacturers of each component

Thats easy, just go to a website that offers a lot of these manufacturers