// FIRST Akrapovic M4 exhaust in the US installed (pics and videos inside!) / TAG MS

[ersin]

Originally Posted by OBMWBrian

That does seem to be the case. The stock F8x exhaust has two catalytic converters in the mid-section, before where the Akra center resonator is. There are no oxygen sensors past these cats, so the car won't know they're gone, but an emissions sniffer will.

I'm more concerned about the OBD II reporting. It needs to be clean plus pass readiness in MD. The fact that there are no O2 sensors past the cats sounds like this could possibly work.


Cheers.

[Alex@TAG]

Originally Posted by ersin

I'm more concerned about the OBD II reporting. It needs to be clean plus pass readiness in MD. The fact that there are no O2 sensors past the cats sounds like this could possibly work.


Cheers.

Yeah so since the Evolution Line system actually just replaces the secondaries, you should be fine

[DR]

What about the valves. The Akrapovic system uses the Original valves, which means that if you are on low throttle 3rd gear the valves will close. Is there a system om the market yet which gives you control over the valves (like exhaustmeister or anything). Do you have a clip of the Akrapovic system when valves are closed.
I have disconnected the valves on the original exhaust so now they stay open. It is awfull on coldstart but i like it very much in third or fourth gear.

[dyy7]

Is the video uploaded with akra downpipe installed? Would like to hear how the full akra system sounds...
With the akra downpipe installed will there be engine check light? or do we need to get the akra delete R?

[Gabe@TAG]

Originally Posted by DR

What about the valves. The Akrapovic system uses the Original valves, which means that if you are on low throttle 3rd gear the valves will close. Is there a system om the market yet which gives you control over the valves (like exhaustmeister or anything). Do you have a clip of the Akrapovic system when valves are closed.
I have disconnected the valves on the original exhaust so now they stay open. It is awfull on coldstart but i like it very much in third or fourth gear.

You can control the valves via the driving mode selection. the valves remain open in sport and sport plus.

[GregW / Oregon]

Originally Posted by Grubbs@TAG

You can control the valves via the driving mode selection. the valves remain open in sport and sport plus.

Don't the valves still only open at a certain RPM or loading condition? I notice the car will get loud all of a sudden, which is disconcerting.

[DR]

I dont think so Grubbs. Even in sport or sport + the valves will close on higher gears when not fully loaded.

SPORT and SPORT PLUS modes, other engine characteristics are selected for controlling the exhaust valves. At lower gears, the exhaust valves are always open, while when higher gears are selected under constant driving conditions, they are closed; however, if the load conditions change accordingly, they open up in a flash. There are also ranges in which we have chosen to close the valves, for instance at low engine speeds in high gears. In these ranges, which are frequently selected in the automatic mode of the M DKG Drivelogic for driving at maximum efficiency, the exhaust tract in turbo engines would have a tendency to drone if there were no damping

http://f80.bimmerpost.com/forums/sho...d.php?t=979417

[DR]

Can you also just order the front section of the Evolution system and connect them to the stock rear muffler. When valves are open what is the difference between the stock muffler and the Akrapovic muffler. The exhaust gasses are going straight through, or do the end tips changes the noise that much.

[Gabe@TAG]

Thought you guys might like to see the M4 in all it's Akrapovic Livery




Let us know what you think!!

[tonymac1]

Originally Posted by Grubbs@TAG

Thought you guys might like to see the M4 in all it's Akrapovic Livery



Let us know what you think!!

Looks great!, do you guys have any other videos of the exhaust? please post some if possible for those who dont have a chance to listen to it in person

[Wes Howell]

Originally Posted by DR

I dont think so Grubbs. Even in sport or sport + the valves will close on higher gears when not fully loaded.

SPORT and SPORT PLUS modes, other engine characteristics are selected for controlling the exhaust valves. At lower gears, the exhaust valves are always open, while when higher gears are selected under constant driving conditions, they are closed; however, if the load conditions change accordingly, they open up in a flash. There are also ranges in which we have chosen to close the valves, for instance at low engine speeds in high gears. In these ranges, which are frequently selected in the automatic mode of the M DKG Drivelogic for driving at maximum efficiency, the exhaust tract in turbo engines would have a tendency to drone if there were no damping

http://f80.bimmerpost.com/forums/sho...d.php?t=979417

The valves do close in higher gears unless you stay pretty heavy on the pedal.

[PABrian]

Hey guys, so back here you mentioned you'd have exact weight numbers for the exhausts pretty soon. Has there been any development on that? Seeing exact numbers would be pretty great, especially if they are broken down by section.

[Gabe@TAG]

Originally Posted by OBMWBrian

Hey guys, so back here you mentioned you'd have exact weight numbers for the exhausts pretty soon. Has there been any development on that? Seeing exact numbers would be pretty great, especially if they are broken down by section.

The Akrapovic site has been updated
The slip on line saves 6lbs
The evolution link pipe saves 9lbs
Total reduction of 15lbs

[kitw]

Originally Posted by DR

I dont think so Grubbs. Even in sport or sport + the valves will close on higher gears when not fully loaded.

SPORT and SPORT PLUS modes, other engine characteristics are selected for controlling the exhaust valves. At lower gears, the exhaust valves are always open, while when higher gears are selected under constant driving conditions, they are closed; however, if the load conditions change accordingly, they open up in a flash. There are also ranges in which we have chosen to close the valves, for instance at low engine speeds in high gears. In these ranges, which are frequently selected in the automatic mode of the M DKG Drivelogic for driving at maximum efficiency, the exhaust tract in turbo engines would have a tendency to drone if there were no damping

http://f80.bimmerpost.com/forums/sho...d.php?t=979417

Yes. There is a range at around 2000 rpm that the valves close under light throttle to prevent drone. At full throttle, the car will leave the valves open all the time.

[04RC51]

Car looks great! Can't wait to order my system!

[PABrian]

Originally Posted by Grubbs@TAG

The Akrapovic site has been updated
The slip on line saves 6lbs
The evolution link pipe saves 9lbs
Total reduction of 15lbs

Thanks for the response. I did see that, but was looking for actual weight numbers, not just reductions.

[Gabe@TAG]

Originally Posted by OBMWBrian

Thanks for the response. I did see that, but was looking for actual weight numbers, not just reductions.

My apologies

The slip on line is 37.5lbs
The evolution link pipe is 17.6lbs

[Gabe@TAG]

We love how a titanium system turns purple after some good use. We just got back from the Targa Trophy Mega rally. After 3 days of HARD driving, we think this exhaust sounds even better. It's been properly broken in and a new video is being made as we speak. We also cant wait to see what our good friend Wes Howell has come up with. Stay tuned!!

[Gabe@TAG]

We here at TAG thought you'd like to see what happens to a full titanium Akrapovic system after it's been broken in. This is a thing of beauty.












What do you guys think? If you have any questions at all regarding any of the parts you see, please feel free to contact us by clicking HERE or Call us at 866-793-5490.

[Carlos@TAG]

[Alex@TAG]

Another Batch of Exhaust System's are due to arrive this week! Give us a ring to make sure we get you a system. They are going quick!

[Carlos@TAG]