Only one of the mufflers seem to be working... Dumb question

[Don Juan]

Originally Posted by r33_RGSport

Done it. No drone, but loosing the low end torque a little.

How did you do it ? our cars valve is electric

[r33_RGSport]

Originally Posted by Don Juan

How did you do it ? our cars valve is electric

My method is remove the module and the spring, then turn the flap to open.
This solution is temporary, since after certain amount of driving, with the vibration, somehow the flap closes by itself.
I have yet to figure out the other way to do this, but since it is my wife's car, I rarely able to mess around with it.

[crackerjack15]

Coat hanger? After taking module/spring off.

I took mine off, but didn't like the low speed drone.

[Gilly1964]

Am I alone in wondering why you would even think about doing this?

BMW pays good money to bright people who have come up with a sophisticated solution to stop this being an open pipe.

As that solution is inevitably expensive to implement it can only be down to efficiency, emissions or economy - so why do armchair mechanics think they have a better solutions?

[CFoote]

Originally Posted by Gilly1964

Am I alone in wondering why you would even think about doing this?

BMW pays good money to bright people who have come up with a sophisticated solution to stop this being an open pipe.

As that solution is inevitably expensive to implement it can only be down to efficiency, emissions or economy - so why do armchair mechanics think they have a better solutions?

I agree - the valve is there to increase backpressure and get more power out of the engine - if exhaust noise is more important, have at it I guess....

Chris

[Don Juan]

Well I did what you mentioned RG and I used a zip tie to hold the valve open...so far is holding and love the growl of the engine. I actually feel it more responsive , specially from the mid to top end...but not sure if it is because of the tune (Jb4) .. :-) ..i guess for tuned cars having a flap open it is required for the higher boost levels but I can see with the stock ECU that the computer will auto compensate and loose power in the low end.

my understanding for the flap valve is to allow the engine to warm up faster and to keep noises down. Also to improve some back pressure for better gas mileage, but is you look at the Mperformance Exhaust, both sides are open..the literature actually says to lower back pressure

" Developed using state-of-the-art CAD and FEM technology, this stainless steel exhaust system unleashes the true sound and character of the TwinPower Turbo 3.0 liter straight six cylinder engine in the xDrive 35i. BMW has carefully engineered this system to enhance exhaust sound while also increasing volume and reducing backpressure"

ummmm

[artem123]

Gentlemen, since when extra exhaust INCREASES engine power?

[alphaod]

Originally Posted by artem123

Gentlemen, since when extra exhaust INCREASES engine power?

If extra exhaust didn't increase power, why would people get fart cans.

[Don Juan]

Originally Posted by artem123

Gentlemen, since when extra exhaust INCREASES engine power?

Exhaust alone does not produce any power if any 1hp and reduction of weight. But if it is put together with a tune and other performance parts (ie : Down Pipe) the gains are big. My understanding is that the extra boost and new electronic mappings of a tune requires all that buildup of exhaust fumes to get out fast. The stock exhaust will prevent that of happening.

[CFoote]

Originally Posted by alphaod

If extra exhaust didn't increase power, why would people get fart cans.

Because they are stupid and don't know any better?

Chris

[r33_RGSport]

Originally Posted by artem123

Gentlemen, since when extra exhaust INCREASES engine power?

On the turbo engine, the easier / non restrictive exhaust , will let the turbo to spools up faster, in return higher boost. With higher boost, you gain more hp.
But, too much flow also not good.

On the normal aspirated engine, also apply the same principal, but can't have too much flow since the engine will loose the low end torque.
That also do apply on the turbo engine with a smaller capacity motor. In result of too much good flow, the low end torque is gone. So you need to drive the engine at higher rpm before it start producing powers.

[42pilot]

Originally Posted by MattBianco

You may get a desired acoustic characteristic from this mod, but the pressure in the pipe is calculated and affects engine/power and emission system performance. Considerable thought was placed into the design by setting a valve to split the exhaust flow. A drop in back-pressure will certainly affect low RPM torque as has stated.

There is no free lunch with this mod. You don't improve high RPM performance as both pipes are already open then. And you lose the need pressure for correct pulsing and drafting of the flowing gas. Two cents.

You nailed it. The most important stat is torque, not HP. And eliminating a feature that helps improve low-end torque (and therefore lowers overall performance) for the sake of tail pipe sound, baffles me.

[knepsterd]

Just had ECS tips installed on my 2015 X line 35
It came with the valence and plug and play exhaust tips that mimic look of rectangular 50.

It actually keeps the right exhaust open even at idle and in non sport mode at any rpm without the need of the MPE. I have MPPK installed. It is plugged in the valve on the right exhaust. Nice surprise AND it now even sounds throatier with both exhausts open.