X4 M exhaust note

[Adcampo]

I was at the gas station yesterday and a guy with a new X4 M was idling next to me.

I could immediately hear how good it sounded. Especially compared to the FXX car. Deep burble. No lawn mower or sewing machine sound at all.

At some point he shut it down and fired it up again and it had a nice roar to it. So much better the the FXX.

Not sure what engine is in the X4 M has. Maybe the same as the GXX? From a couple clips I have heard from the new GXX it seems still not have a great sound, but I could be wrong.

I have the AA midpipe on my ZHP and I wish it sounded half as good as the X4 M.

[rmanm4]

X4M has the new S58 engine. S58 is mostly based on the S55. More power, more capable tune on stock components and crank hub issue that BMW refuses to acknowledge has been fixed!

[spuntyb]

It uses a version of the S58 engine with twin single scroll turbos and a closed deck vs the S55 in the F80

https://bmwtuning.co/s55-vs-s58/

[RugbyBro]

To my ears, S58 in X3M & X4M doesn’t sound significantly different to S55 as they have extremely similar exhaust design. S58 in G8X sounds a bit better but still not worlds apart

[mjponti]

I agree, I actually have both now. 2017 F80 Comp and 2021 X4MC.

I think the X4MC note is a bit deeper than the F80 comp exhaust but not a huge difference. I have a Remus axle back on the F80 so it sounds better than the X4 to me haha.

[Adcampo]

Originally Posted by mjponti

I agree, I actually have both now. 2017 F80 Comp and 2021 X4MC.

I think the X4MC note is a bit deeper than the F80 comp exhaust but not a huge difference. I have a Remus axle back on the F80 so it sounds better than the X4 to me haha.

You would be the expert owning both. I would say it definitely sounded deeper. And zero lawn mower effect.

[JamRWS6]

Originally Posted by spuntyb

It uses a version of the S58 engine with twin single scroll turbos and a closed deck vs the S55 in the F80

https://bmwtuning.co/s55-vs-s58/

S55 is also closed deck. In a lot of ways the S58 is more related to the B58 than the S55.

[RugbyBro]

Originally Posted by JamRWS6

S55 is also closed deck. In a lot of ways the S58 is more related to the B58 than the S55.

*B57*

[swagon]

Originally Posted by RugbyBro

*B57*

Yup, B57 diesel.

[maddmatth]

BMW uses an equal length exhaust with the S58 engine to give it the more traditional inline 6 sound. I'm not sure if that applies to the X3/4 version or just the M3/4.
I think an S55 with equal length would sound very similar.

Have heard them in person too (X4M as well as the new M3/4) on a track, they sure do sound good when being revved out

[RugbyBro]

Originally Posted by maddmatth

BMW uses an equal length exhaust with the S58 engine to give it the more traditional inline 6 sound. I'm not sure if that applies to the X3/4 version or just the M3/4.
I think an S55 with equal length would sound very similar.

Have heard them in person too (X4M as well as the new M3/4) on a track, they sure do sound good when being revved out

I don't believe this is true. X3M & X4M use a similar exhaust route to S55 (and nearly all twin cylinder bank I6 BMWs over their history) and G8X has additional piping to push the lengths of the pipes to be closer, but it does not sound equal length at all. G8X S58 also sounds a bit smoother because it has an additional resonator - with both resonators removed it sounds very similar to S55 even in G8X form (see vids on the G8X forums). If you want to hear an EL S58, search up valvetronic's mid pipe video - it is distinctly different from the stock sound.

[maddmatth]

Originally Posted by RugbyBro

I don't believe this is true. X3M & X4M use a similar exhaust route to S55 (and nearly all twin cylinder bank I6 BMWs over their history) and G8X has additional piping to push the lengths of the pipes to be closer, but it does not sound equal length at all. G8X S58 also sounds a bit smoother because it has an additional resonator - with both resonators removed it sounds very similar to S55 even in G8X form (see vids on the G8X forums). If you want to hear an EL S58, search up valvetronic's mid pipe video - it is distinctly different from the stock sound.

Ah interesting Wonder why BMW didn't go all the way to equal length, maybe they wanted to keep the sound more distinct.
Regardless, to my ears they sounded great in person and for a stock car, surprisingly loud. I thought the OPF would result in a more muted sound but it was still great IMO (actually not 100% sure NZ versions have the OPF, but the BMW staff seemed to think they did when I asked).

[Kilabyte]

Originally Posted by RugbyBro

I don't believe this is true. X3M & X4M use a similar exhaust route to S55 (and nearly all twin cylinder bank I6 BMWs over their history) and G8X has additional piping to push the lengths of the pipes to be closer, but it does not sound equal length at all. G8X S58 also sounds a bit smoother because it has an additional resonator - with both resonators removed it sounds very similar to S55 even in G8X form (see vids on the G8X forums). If you want to hear an EL S58, search up valvetronic's mid pipe video - it is distinctly different from the stock sound.

Yup, every S58 video I've seen so far it sounds like crap compared to a true EL, I might be mistaken but the difference is still something around 6 inches between banks? Sounds better than a stock S55 which was more than double that but it's still very meh IMO, I still hear that Pontiac V6

[Kilabyte]

Originally Posted by maddmatth

Ah interesting Wonder why BMW didn't go all the way to equal length, maybe they wanted to keep the sound more distinct.

It's the packaging, one turbo sits behind the other. It's probably not easy to make it fit without some unorthodox design like the AA mid. I don't see BMW doing the loop around the diff either because people who make these decisions are not car people


It's not "distinct", the rest of the 6 cylinder world agrees that the these cars sound horrible, on every forum... ever. Some hardcore fanboys here refuse to listen

While we have struggled to equalize the manifolds others wanted the opposite:

Different platform but IMO it sounds insanely good compared to stock

[swagon]

Originally Posted by Kilabyte

Some hardcore fanboys here refuse to listen

Eh, it's all personal. I wouldn't want my S55 to sound like my N55. I like that it's different to the 135i, and in stock form (not any of the catless garbage), it sounds good. Especially with the ASD off inside. Does a stock 2012 335is exhaust sound better? Yes, for sure.

[maddmatth]

Originally Posted by Kilabyte

It's not "distinct", the rest of the 6 cylinder world agrees that the these cars sound horrible, on every forum... ever. Some hardcore fanboys here refuse to listen

Well damn I'm sorry for liking it

[ntg44]

Originally Posted by Kilabyte

It's the packaging, one turbo sits behind the other. It's probably not easy to make it fit without some unorthodox design like the AA mid. I don't see BMW doing the loop around the diff either because people who make these decisions are not car people

If only they would have designed the turbo orientation similar to N54 configuration, with the hot sides facing each other and cold sides opposite each other. This would make EL so much easier, and probably already packaged that way from the factory. Could make a dual to single downpipe right from the get go and avoid all these pipe routing gymnastics the EL exhausts need to go through .

[spool twice]

The front/rear downpipes on the S58 x3m/x4m has a shorter difference between them than our s55's.

[blkcow]

Originally Posted by maddmatth

Well damn I'm sorry for liking it

I feel like the parent of an ugly kid - yes it’s not the greatest but you learned to love it!

[TimmyM56]

Originally Posted by swagon

I wouldn't want my S55 to sound like my N55.

I absolutely do, but it's hard to find something good to pair with the EL midpipe to make it sound exactly like an N55. It's annoying to see BMW hasn't learned with the X3M/X4M and the G8x cars and having them not sound proper.