2016 640i m sport gran coupe exhaust flap

[arucano]

There are two type of valve actuators. The pre-lci exhaust had a vacuum unit to open the valve. the later units are electronic actuators. The vacuum units just need vacuum applied to actuate. You can use a solenoid valve routed to a vacuum source. The later units require a controller. The positioning is done using Pulse Width Modulation to change the position of the valve.

[RJV3]

Originally Posted by arucano

There are two type of valve actuators. The pre-lci exhaust had a vacuum unit to open the valve. the later units are electronic actuators. The vacuum units just need vacuum applied to actuate. You can use a solenoid valve routed to a vacuum source. The later units require a controller. The positioning is done using Pulse Width Modulation to change the position of the valve.

Thanks for the clarification. So since I have an LCI, the only way to retain valve function and run and aftermarket exhaust is to get a valved exhaust system with valve controller? Based on your explanation, I assume I cannot use the m6 mufflers and salvage the valve function because my LCI 640 uses a seperate controller to actuate the valves. Is my understanding correct?

[arucano]

Not speaking from experience, but if you presently have electronic flaps, you should be able to use the electronic flaps of a different model with the same controller. The point is whether you are maintaining the same flap "motors" (vacuum or electronic). As far as the mufler swap, there were some discussion a while back on what saps are possible.

[Chaos236]

My 17 604 GC has a very simple to zip tie up(big zip tie) to hold open the flap right behind the tip.

[niksha87]

Can you please share some picture how it looks and how you did it?
I have 17 640 GC
Thanks