[Ahmed Abdullatif]

Hello everyone, i have installed Mppsk a fee days ago and I experienced the following:

- Feel more power specially on the mid range
- when revving on idle in sport mode is awesome bit I realized only one flap is open even in cruising in sport mode

Is the flaps suppose to open in sport mode or only one flap? Is there a difference when it comes to the flaps when cruising or in idle?

[bimmer456]

Originally Posted by Ahmed Abdullatif

Hello everyone, i have installed Mppsk a fee days ago and I experienced the following:

- Feel more power specially on the mid range
- when revving on idle in sport mode is awesome bit I realized only one flap is open even in cruising in sport mode

Is the flaps suppose to open in sport mode or only one flap? Is there a difference when it comes to the flaps when cruising or in idle?

Should be open in sport mode but may not open right away when the engine is cold. Also if idling and going into sport mode it won't open until you tap on the accelerator.

[Ahmed Abdullatif]

Originally Posted by bimmer456

Should be open in sport mode but may not open right away when the engine is cold. Also if idling and going into sport mode it won't open until you tap on the accelerator.

When i rev in idle in sport mode, only one flap opens

[bimmer456]

Originally Posted by Ahmed Abdullatif

When i rev in idle in sport mode, only one flap opens

How do you know this are you having someone look at the exhaust while you rev it? You should hear a difference in the exhaust note.

[Ahmed Abdullatif]

Originally Posted by bimmer456

How do you know this are you having someone look at the exhaust while you rev it? You should hear a difference in the exhaust note.

When i switch to sport mode, i look at the flaps and only one is opened.

I dont know if they should work in parallel.

[jh_f30]

Originally Posted by Ahmed Abdullatif

When i switch to sport mode, i look at the flaps and only one is opened.

I dont know if they should work in parallel.

There is only one flap.

[Beek]

Originally Posted by jh_f30

There is only one flap.

MPPSK has two valves, stock system has only one valve.

[BEAR-AvHistory]

You can code them both open all the time.

440 MPPSK open valves

https://youtu.be/BzOPTfYtFBQ

[bimmer456]

Originally Posted by Ahmed Abdullatif

When i switch to sport mode, i look at the flaps and only one is opened.

I dont know if they should work in parallel.

If you are in P it will not open right away when switching to sport. Did you look at it before and after switching to sport?

[Ahmed Abdullatif]

Originally Posted by bimmer456

If you are in P it will not open right away when switching to sport. Did you look at it before and after switching to sport?

No but i will give it a look, but only one flap opens when in sport.

[bimmer456]

Originally Posted by Ahmed Abdullatif

No but i will give it a look, but only one flap opens when in sport.

You may need to blip the throttle after switching to sport to get the valve to open. The engine has to be warmed up too.

[Ahmed Abdullatif]

Originally Posted by bimmer456

You may need to blip the throttle after switching to sport to get the valve to open. The engine has to be warmed up too.

I did and only one flaps opens

[bimmer456]

Originally Posted by Ahmed Abdullatif

I did and only one flaps opens

Does it sound different while idling or the same? You may have to have them check it. Also you may have to drive it around the block first.

[Ahmed Abdullatif]

Even after a 5 mins drive in sport mode only one flap is open and i dont feel much differernce whn driving in sport mode compared to comfort only a bit

[jh_f30]

Originally Posted by Beek

MPPSK has two valves, stock system has only one valve.

Oh, my bad! I learned something new today!

[bimmer456]

Originally Posted by Ahmed Abdullatif

Even after a 5 mins drive in sport mode only one flap is open and i dont feel much differernce whn driving in sport mode compared to comfort only a bit

I would bring it back to the dealer to see if they flashed the DME correctly. Let them know what you are experiencing.

[bimmer456]

Originally Posted by jh_f30

Oh, my bad! I learned something new today!

Where does the exhaust go if both valves are closed?

[supermarket]

Originally Posted by bimmer456

Where does the exhaust go if both valves are closed?

The path through the muffler is always open. The valves open lower-resistance paths that avoid the muffler.

[bimmer456]

Originally Posted by supermarket

The path through the muffler is always open. The valves open lower-resistance paths that avoid the muffler.

So there is no situation where only one valve is open, it's both open or both closed?

[supermarket]

Originally Posted by bimmer456

So there is no situation where only one valve is open, it's both open or both closed?

There’s only one exhaust flap control signal from the DME. The two valves on the MPPSK exhaust are driven through a Y-cable adapter supplied with the kit. Each valve gets the same signal at the same time. They shouldn’t go cross-eyed.

If only one valve operates, the Y-cable could be missing, damaged, or not fully connected. Or one valve may have seized.

(Disclaimer: I don’t have an MPPSK fitted, but I’ve seen the kit and technical documentation.)

[bimmer456]

Originally Posted by supermarket

There's only one exhaust flap control signal from the DME. The two valves on the MPPSK exhaust are driven through a Y-cable adapter supplied with the kit. Each valve gets the same signal at the same time. They shouldn't go cross-eyed.

If only one valve operates, the Y-cable could be missing, damaged, or not fully connected. Or one valve may have seized.

(Disclaimer: I don't have an MPPSK fitted, but I've seen the kit and technical documentation.)

Makes sense as they have to rig something to make two valves work with a single connection that goes to the stock exhaust. So the valves are closed in comfort to force exhaust through the muffler but open to allow it to go through the straight pipe.

[BEAR-AvHistory]

Originally Posted by bimmer456

Where does the exhaust go if both valves are closed?

The piping is not the same on the two mufflers.


440 MPPSK dual flapper


Standard piping single flapper