[jspiegel]

I might be crazy, but I do not think my X4MC LCI exhaust sounds right (everything is stock).

Here is a link to the cold start of my car: https://drive.google.com/file/d/1Rep...ew?usp=sharing

Here is a link to a LCI X3M Comp cold start that sounds good:

I purchased a midpipe, had it installed, but removed it because it sounded awful. The cold start sounded like a machine gun firing off. Now I'm thinking that something is actually wrong with my exhaust to make the exhaust sound bad and not the midpipe.

Does anyone agree with me that it doesn't sound right? If yes, do you have any clue as to what the problem would be? I would need to bring it into the dealer for them to fix it, but I would want confirmation from the forum before I bring it in.

[danniexi]

Originally Posted by jspiegel

Here is a link to the cold start of my car: https://drive.google.com/file/d/1Rep...ew?usp=sharing

sounds fine.

Originally Posted by jspiegel

Here is a link to a LCI X3M Comp cold start that sounds good: https://www.youtube.com/watch?v=A3zPxWGGNP4

this is with the valves open (sport +). that's why it sounds different.

[MackSea70]

My 22 X3MC sounds exactly like that. (IMHO - cold start on the S58 is pretty awful). Moreover, I wish I understood BMW's rationale for going to high idle on almost EVERY start. I'll literally drive 30 minutes, park for 5 minutes and it will do at least a brief high idle.

Once it's warmed up and the valves are open AND has a load on it, it sounds pretty good. But revs and cold idle = yuck.

Mine's leased and I know a short term member of my fleet so I'll live with it.

[thestimp]

Thats normal, and it sucks, they ruined the sound of this car, intake is quiet, exhaust is too neutered. You need to go high flow cats and straight pipes with a resonator someone should make it soon...

[STi from DSM]

I know what the problem is... It is too quiet!

That is how it is supposed to sound, the good ole BMW Lawnmower on startup.

[chimp]

I could be mistaken but I think that second link is actually a Pre LCI. I have a 2021 and 2022 X4MC and my 2022 doesn't have those honeycomb accents in the middle there by the exhaust but the 2021 does. Maybe the X3M is different. I will say my 2021 sounds much louder than my 2022.

[Mike02z]

Ha! That’s my clip! You didn’t post the “after” ER midpipe.

[jspiegel]

Originally Posted by Mike02z

Ha! That’s my clip! You didn’t post the “after” ER midpipe.

I think your setup sounds sweet with the ER midpipe installed. I used your stock video because I thought it was the cleanest video I found online.

I didn't realize the cold start was with the flaps open though, so that makes more sense that they sound different.

What mod would make that exhaust sound better on a cold start sound better?

Do people just start their car in sport plus?

[Mike02z]

Originally Posted by jspiegel

I think your setup sounds sweet with the ER midpipe installed. I used your stock video because I thought it was the cleanest video I found online.

I didn't realize the cold start was with the flaps open though, so that makes more sense that they sound different.

What mod would make that exhaust sound better on a cold start sound better?

Do people just start their car in sport plus?

No worries about using the clip. Glad it helped.

My understanding is you cannot keep the valves closed on cold start. They stay open in every mode. I’m guessing the exhaust controllers you hard wire might be able to keep the flaps closed during cold start.Cold start with the ER sounds horrible and is very tinny/raspy until the idle drops. After that I love the sound. I wish I could quiet it down during cold start by keeping a valves closed for the initial 2 minutes. Luckily I don’t have a commute so no early morning starts. I’m sure it still pisses the neighbors off 😁

The X3 M sounds good but it will never sound like a V8. It is what it is. I’d take the X3 6 cyl over the “Hot V” 4.4 V8 you get in the X5 M50i/M. It may sound better but turbos in the valley seems like a really big issue as the engine ages.

[new2the3]

By default valves are closed on start up. Hit the engine start button one time but do not turn on the engine. Put engine in sport plus, tap gas pedal to open valves. Now turn on your engine and it will be much louder and sound like a beast.

[dooo]

The only way to get rid of the high Rev cold start is to tune it out. Unfortunately with the ECU being locked, it's not an option. BMW does this cold start as a default to get the cat warmed up asap.

[Mike02z]

Originally Posted by new2the3

By default valves are closed on start up. Hit the engine start button one time but do not turn on the engine. Put engine in sport plus, tap gas pedal to open valves. Now turn on your engine and it will be much louder and sound like a beast.

I don’t think so. They appear to be open in every mode on cold start. As soon as it idles down the valves close

[Mike02z]

Originally Posted by chimp

I could be mistaken but I think that second link is actually a Pre LCI. I have a 2021 and 2022 X4MC and my 2022 doesn't have those honeycomb accents in the middle there by the exhaust but the 2021 does. Maybe the X3M is different. I will say my 2021 sounds much louder than my 2022.

If your talking about my MBB X3 MC it is a 22.

[danniexi]

Originally Posted by Mike02z

I don’t think so. They appear to be open in every mode on cold start. As soon as it idles down the valves close

exhaust valves are closed to keep the noise down. it's the wastegates that open up and rpms raised to quickly heat up the catalytic converters (which is why cold start is so damn loud).

next time you start the car on a cold engine, switch between "efficient" and "sport +" and you'll hear the difference. with the valves open, the exhaust tone emits lower frequencies (deeper, bass tones).

[Mike02z]

Originally Posted by danniexi

exhaust valves are closed to keep the noise down. it's the wastegates that open up and rpms raised to quickly heat up the catalytic converters (which is why cold start is so damn loud).

next time you start the car on a cold engine, switch between "efficient" and "sport +" and you'll hear the difference. with the valves open, the exhaust tone emits lower frequencies (deeper, bass tones).

You may be right. With the ER midpipe my exhaust sounds the same in all 3 modes. Obnoxious on cold start no matter what mode I’m in. It defaults to Efficient and it’s still horrible. Once the revs drop it sounds great! Love the pops and crackles on decel with the ER. Well worth the 950.

[chimp]

Originally Posted by Mike02z

If your talking about my MBB X3 MC it is a 22.

Interesting. I guess that rear section of the X4MC and X3MC must be different.

[Mike02z]

Originally Posted by chimp

Interesting. I guess that rear section of the X4MC and X3MC must be different.

The X4 MC does look different in the below.

[2020X3MCDG]

sounds completely normal to me. I do not like the cold start valve open sound. I usually leave mine closed until I drive off and out of the neighborhood.

After it is warmed up and driving, wot, etc. I think it sounds great for it not being an 8 cyl and stock exhaust.

[STi from DSM]

Originally Posted by Mike02z

I don’t think so. They appear to be open in every mode on cold start. As soon as it idles down the valves close

Valves are open on initial cold start until the revs die down, then it goes into whatever mode you have it in. Noting of course that if you have it in Sport + you have to cycle through that again to get the valves to open up.

There was a video where a guy in an M2C showed how burbles are dependent drive mode. This is also true when you pull the active exhaust fuse. You could see the flap open in all modes, but only got burbles in sport and sport +.

[STi from DSM]

Originally Posted by Mike02z

The X4 MC does look different in the below.

X3M and X4M share the same catback exhaust but get different tip sizes in the aftermarket. (Which I think is ridiculous)