M135i exhaust question - is one a replica?

[sam303]

Took delivery of my new M135i yesterday. (I know, I know, worst "I took delivery of my new M135i yesterday" thread ever...)

Went out for a wee run yesterday, all good.

Today the Mrs piled the kids into it and took them off to the swimming pool whilst I watched from upstairs. I noticed that there was only water vapour coming from one exhaust - the driver side one. It was quite obvious i.e. there was lots of vapour coming out of one, and none coming out of the other. (Quite a chilly day here in Scotland.)

So - anyone know why? Surely the left one isn't a fake one? (Unfortunately, googling "M135i exhaust" and so on just brings up endless discussions about the 'enhanced' engine/exhaust/induction note in the cabin.) So can anyone give any definitive info on why I only saw vapour from one exhaust tip?

[GroundEffect]

Have a look underneath...

They are probably both real but one having a longer exit than the other eating up the vapour.

[nickfrog]

No they are both real but one has a valve that closes on cold starts and below certain rpm.

[AdamGP]

I would say the one pipe has a vacuum flap which opens at a certain RPM.

[UpsideDown]

I have also noticed this on mine on cold mornings. When you first start the car water vapour only comes out of the right hand exhaust, however after a couple of minutes the left hand one then kicks in. Not sure why this would be the case though???

[nickfrog]

Look at posts 3 and 4 in this very thread...

[Driver101]

That's normal. Once the car is warmed up the flap in the other side of the exhaust will open.

[Dave Hedgehog]

Driver101 said:

Once warmed up the flap will open.

alcohol speeds this up

[B3ALP]

Dave Hedgehog said:

Driver101 said:

Once warmed up the flap will open.

alcohol speeds this up

[Driver101]

Dave Hedgehog said:

alcohol speeds this up

Which pipe do you plan sticking it?

[B3ALP]

Driver101 said:

Dave Hedgehog said:

alcohol speeds this up

Which pipe do you plan sticking it?