[Info@mad-us.com]

Originally Posted by Angmar

I tried the fuse pull during cold start….It made the car loud in low rpm but for some reason the car sounds quieter at full throttle so I put the fuse back in.

Thought cold start was closed valve.

[Angmar]

Maybe in comfort mode….My car is loud on cold start in sport plus.

[JABCAT]

Originally Posted by Angmar

I tried the fuse pull during cold start….It made the car loud in low rpm but for some reason the car sounds quieter at full throttle so I put the fuse back in.

You have to let the car get up to operating temp, open the valves then pull the fuse. The valves will stay open in every mode, cold start, warm start, forever until you put the fuse back in

[Angmar]

Originally Posted by JABCAT

You have to let the car get up to operating temp, open the valves then pull the fuse. The valves will stay open in every mode, cold start, warm start, forever until you put the fuse back in

Thanks for the response….why does the car sound so loud on cold start on sport plus? That like first 30 seconds on startup where it’s really loud and then it gets significantly more quiet. I thought if I pulled the fuse during that it would be at the most open point I could get the valve to open no? Is it loud for another reason like the waste gate is allowing full bypass to warm the catalytic converters or something?

[mike@x-ph.com]

Originally Posted by Angmar

Thanks for the response….why does the car sound so loud on cold start on sport plus? That like first 30 seconds on startup where it’s really loud and then it gets significantly more quiet. I thought if I pulled the fuse during that it would be at the most open point I could get the valve to open no? Is it loud for another reason like the waste gate is allowing full bypass to warm the catalytic converters or something?

the cold start sound has nothing to do with the valves. pulling the fuse does not help as the valves are closed during the cold start.

It's got to do with emissions and mpg to warm up the cats as soon as possible. you need a flash tune to turn off the cold start

[Info@mad-us.com]

Originally Posted by Angmar

Thanks for the response….why does the car sound so loud on cold start on sport plus? That like first 30 seconds on startup where it’s really loud and then it gets significantly more quiet. I thought if I pulled the fuse during that it would be at the most open point I could get the valve to open no? Is it loud for another reason like the waste gate is allowing full bypass to warm the catalytic converters or something?

Yup thats cold start. This is why people choose valve controllers so you aren't locked open with no option.

[Dave07997S]

Originally Posted by Info@mad-us.com

Thought cold start was closed valve.

You can put it in sport+ before start up and it opens the valve even before warmup.

[JABCAT]

Originally Posted by Dave07997S

You can put it in sport+ before start up and it opens the valve even before warmup.

I've played with this multiple times, and it does not open the valves before the car is warmed up. At least on my car or my wife's X3MC. :

[Info@mad-us.com]

Originally Posted by JABCAT

I've played with this multiple times, and it does not open the valves before the car is warmed up. At least on my car or my wife's X3MC. :

Same I think it has to be out of cold start to enable M mode.

[Dave07997S]

Originally Posted by JABCAT

I've played with this multiple times, and it does not open the valves before the car is warmed up. At least on my car or my wife's X3MC. :

It does on the M2...

[JABCAT]

Originally Posted by Dave07997S

It does on the M2...

Video it. Just did this last week, and they didn't open until the car was warm.

[Dave07997S]

Originally Posted by JABCAT

Video it. Just did this last week, and they didn't open until the car was warm.

Here you go, cold start engine. Sport Plus the flap does open. Sorry for my voice, getting over a cold.

[Tricki]

By far, pulling fuse 203 is the beat and easiest without have to spend $$$.
Even at 70-80% it sound so much better.. Maybe the flaps open at 100% while at full throttle in 3rd or 4th gears?? If thats the case put a friend in the trunk who can pull the fuse while while driving on the freeway at that speed? Lol
Worth a try 🤷🏽‍♂️

[Dave07997S]

Nevermind

[Whytar]

There just seems something not right about a performance car with an already restrictive exhaust system, having flaps that only ever open to 85%.
It's well known that turbocharged motors work much more efficiently the lower the back pressure in the system.
Because of this, I'm going to just buy an exhaust flap control unit (probably SST) and have the flaps 100% open, then not touch it in any mode.

[mike@x-ph.com]

Originally Posted by Whytar

There just seems something not right about a performance car with an already restrictive exhaust system, having flaps that only ever open to 85%.
It's well known that turbocharged motors work much more efficiently the lower the back pressure in the system.
Because of this, I'm going to just buy an exhaust flap control unit (probably SST) and have the flaps 100% open, then not touch it in any mode.

[Blacktemplar]

Originally Posted by Tricki

By far, pulling fuse 203 is the beat and easiest without have to spend $$$.
Even at 70-80% it sound so much better.. Maybe the flaps open at 100% while at full throttle in 3rd or 4th gears?? If thats the case put a friend in the trunk who can pull the fuse while while driving on the freeway at that speed? Lol
Worth a try 🤷🏽‍♂️

Agreed, makes the car sound so much better.

Has anyone who's pulled fuse 203 experienced any rattling from the exhaust? I'm not entirely certain, but I think I occasionally hear something when idling