[iCARMIX]

     Featured on BIMMERPOST.com

How does everybody feel about the sound of the M5 Competition LCI?
The reason I am asking is because this customer I had in my shop wanted more sound for his 625 horses so he ended up getting a Slip-ON Titanium System from AK, which comes with carbon fiber tips.
The exhaust is obviously louder and, according to their official data, it's 23.7% (16.5kg-12.6kg) lighter than stock, fetches about 10.9 HP extra, and torque gains of 14.7 Nm. The installation took about a whole day, but in the end it was totally worth it.
Enjoy the photos, I know I did:

[mike@x-ph.com]

[PDOT]

Is the sound kit needed?

[Tommy L Garage]

This is an hour long job. Just curious what took so long?

[iCARMIX]

Originally Posted by Tommy L Garage

This is an hour long job. Just curious what took so long?

One hour long? With the valves and the electrical parts for them? I would love to learn how to do that faster if you can, if you have a video doing it please do post it

[iCARMIX]

Originally Posted by PDOT

Is the sound kit needed?

It's optional. If you don't include the sound kit, the sound will change based on your driving

[PDOT]

Originally Posted by iCARMIX

It's optional. If you don't include the sound kit, the sound will change based on your driving

So the exhaust button is no longer functional?

[iCARMIX]

Originally Posted by PDOT

So the exhaust button is no longer functional?

Driving mode is still functional, no changes there, with or without the sound kit

[PDOT]

Originally Posted by iCARMIX

Driving mode is still functional, no changes there, with or without the sound kit

Not driving mode, but the exhaust flap button?

[iCARMIX]

Originally Posted by PDOT

Not driving mode, but the exhaust flap button?

Can you please take a photo of that button and show me?
I apologize but I wanna make sure there's nothing lost in translation, and that I know exactly which button you are referring to.

[PDOT]

Originally Posted by iCARMIX

Can you please take a photo of that button and show me?
I apologize but I wanna make sure there's nothing lost in translation, and that I know exactly which button you are referring to.

See attached.

[iCARMIX]

Originally Posted by PDOT

See attached.

Do we have a definite answer yet? Is this button controlling the valves or just the ASD inside the car? Debates are still ongoing. In any case, installing the sound kit won't affect the function of this button.

[RobRed]

That button does influence the valve position in the exhaust - not directly but tells the exhaust ecu what the drivers preference is. It will act accordingly depending input parameters like Drive mode and engine RPM etc.

When its off the exhaust valves will remain closed

[will0621]

Originally Posted by PDOT

Is the sound kit needed?

You don’t need the sound kit, the OEM actuators can be swapped onto the Akra and the exhaust flaps function like OEM with comfort/sport vs sport+ mode, as well as the exhaust button in the cabin.

[windtendo]

The exhaust should be completely plug and play. The extra electronics that come in the box aren't necessary. The valves connect into the OEM connectors. This isn't more than a few hour job. I've had the full catback Akrapovic exhaust installed on two of my F90 M5s now.

[NoMods]

so tempting, when it's in sport mode will it snap, crackle and pop even louder? what about other settings?

[carseatsm5]

Originally Posted by armoredsaint

so tempting, when it's in sport mode will it snap, crackle and pop even louder? what about other settings?

It just sounds louder and better. Very hard to describe an exhaust but there are videos you can easily find.

I have the axle back and it sounds great. Main benefit of the full cat back is you also delete the resonator on the midpipe. And lighter certainly.

But they are pricey! Still I find myself driving a lot with it in sports mode and just listening to the exhaust. Many people say an Akra (or MPE) is their favorite mod on the car.

[NoMods]

Originally Posted by carseatsm5

It just sounds louder and better. Very hard to describe an exhaust but there are videos you can easily find.

I have the axle back and it sounds great. Main benefit of the full cat back is you also delete the resonator on the midpipe. And lighter certainly.

But they are pricey! Still I find myself driving a lot with it in sports mode and just listening to the exhaust. Many people say an Akra (or MPE) is their favorite mod on the car.

MPE is that the BMW MP exhaust?

[carseatsm5]

Originally Posted by armoredsaint

MPE is that the BMW MP exhaust?

Yes. But MPE has no valves to quiet it down when that’s called for.

So if you’re cold starting and worried about the neighbors with an MPE then you’d better go buy some pool noodles to jam back there because your exhaust button no longer does anything.

[NoMods]

What would you recommend for a plug-in-play replacement for a stock exhaust on the M5 and still retain the valves? Still Akra or Eisenmann sounds good too? I was thinking axle back?

[pbonsalb]

If money is no object, the Akra would be my choice. But not at half the cost of a built engine for next to no added power.

[carseatsm5]

I think consensus would be best valved system on the F90 is Akrapovic but it’s also most expensive by a mile. If valves are not necessary, then I’d say consensus is a tie between MPE and Akrapovic.

Next tier the three most popular brands are Remus, GTHAUS Meisterschaft, and Eisenmann. Definitely there are valved options among those but I’m not smart on them.

The other thing many people do that is much cheaper is just buy the Dinan resonator delete kit and install it on their stock exhaust. Probably get 50%+ of the sound benefit of a full, new system for about 25% of the price.

I have the axle back Akra and plan to install the Dinan x pipe. Happy with the axle back alone but want to take it up a notch by deleting the resonator.

For all of them, best bet is search the forum or YouTube for videos. Exhaust note is a very personal thing imo. But definitely do an exhaust mod of some kind because the V8 needs to be allowed to sing!