BMW M4 sounds bad. M2, Supra, Skyline are wonderful - why?
Discussion
I am posting in the General section since I don't believe this is a BMW specific question, but rather an engineering or technical issue.
I chose 'M4' for the subject line so it didn't get confused with older generations of M3s which sound wonderful but aren't turbocharged.
My F80 M3 has a terrible sounding exhaust note, so bad in fact that I might punt the car in favour of something that makes nicer music. The confusing part is trying to understand why the S55 inline six sounds so bad (gruff, blunt and blatty) while other twin turbo inline sixes such as BMW's own N54, the Supra's 2JZ, the Skyline's RB26/28, etc sound sonorous, silky, smooth and simply lovely.
My F80 has a 6spd manual 'box so it doesn't have the artificial flatulence during shifts that the DCT models have and I am aware that the excessive burbling sounds on decel can be coded out through software but everywhere from idle to full throttle the exhaust note ranges from uninspiring to downright poor. I have fitted a Remus back box (electronic valves retained) and while it makes the car louder and arguably more aggressive it doesn't add any quality to the tone or inject any of the inline six magic that is missing.
Why is this? Is there an architectural or mechanical reason why the S55 in the M3/M4 (now M2 Competition) can't sound glorious like other sixes do?
I chose 'M4' for the subject line so it didn't get confused with older generations of M3s which sound wonderful but aren't turbocharged.
My F80 M3 has a terrible sounding exhaust note, so bad in fact that I might punt the car in favour of something that makes nicer music. The confusing part is trying to understand why the S55 inline six sounds so bad (gruff, blunt and blatty) while other twin turbo inline sixes such as BMW's own N54, the Supra's 2JZ, the Skyline's RB26/28, etc sound sonorous, silky, smooth and simply lovely.
My F80 has a 6spd manual 'box so it doesn't have the artificial flatulence during shifts that the DCT models have and I am aware that the excessive burbling sounds on decel can be coded out through software but everywhere from idle to full throttle the exhaust note ranges from uninspiring to downright poor. I have fitted a Remus back box (electronic valves retained) and while it makes the car louder and arguably more aggressive it doesn't add any quality to the tone or inject any of the inline six magic that is missing.
Why is this? Is there an architectural or mechanical reason why the S55 in the M3/M4 (now M2 Competition) can't sound glorious like other sixes do?
airiscool said:
I am posting in the General section since I don't believe this is a BMW specific question, but rather an engineering or technical issue.
I chose 'M4' for the subject line so it didn't get confused with older generations of M3s which sound wonderful but aren't turbocharged.
My F80 M3 has a terrible sounding exhaust note, so bad in fact that I might punt the car in favour of something that makes nicer music. The confusing part is trying to understand why the S55 inline six sounds so bad (gruff, blunt and blatty) while other twin turbo inline sixes such as BMW's own N54, the Supra's 2JZ, the Skyline's RB26/28, etc sound sonorous, silky, smooth and simply lovely.
My F80 has a 6spd manual 'box so it doesn't have the artificial flatulence during shifts that the DCT models have and I am aware that the excessive burbling sounds on decel can be coded out through software but everywhere from idle to full throttle the exhaust note ranges from uninspiring to downright poor. I have fitted a Remus back box (electronic valves retained) and while it makes the car louder and arguably more aggressive it doesn't add any quality to the tone or inject any of the inline six magic that is missing.
Why is this? Is there an architectural or mechanical reason why the S55 in the M3/M4 (now M2 Competition) can't sound glorious like other sixes do?
I would assume its a combination of things, my bet is mostly manifold design I chose 'M4' for the subject line so it didn't get confused with older generations of M3s which sound wonderful but aren't turbocharged.
My F80 M3 has a terrible sounding exhaust note, so bad in fact that I might punt the car in favour of something that makes nicer music. The confusing part is trying to understand why the S55 inline six sounds so bad (gruff, blunt and blatty) while other twin turbo inline sixes such as BMW's own N54, the Supra's 2JZ, the Skyline's RB26/28, etc sound sonorous, silky, smooth and simply lovely.
My F80 has a 6spd manual 'box so it doesn't have the artificial flatulence during shifts that the DCT models have and I am aware that the excessive burbling sounds on decel can be coded out through software but everywhere from idle to full throttle the exhaust note ranges from uninspiring to downright poor. I have fitted a Remus back box (electronic valves retained) and while it makes the car louder and arguably more aggressive it doesn't add any quality to the tone or inject any of the inline six magic that is missing.
Why is this? Is there an architectural or mechanical reason why the S55 in the M3/M4 (now M2 Competition) can't sound glorious like other sixes do?
Quick bit of googling may reveal why
https://www.bmwblog.com/2014/04/23/bmw-m3-bmw-m4-i...
cptsideways said:
I would assume its a combination of things, my bet is mostly manifold design
Quick bit of googling may reveal why
https://www.bmwblog.com/2014/04/23/bmw-m3-bmw-m4-i...
I read that article but it didn't offer any insight into the poor exhaust note.Quick bit of googling may reveal why
https://www.bmwblog.com/2014/04/23/bmw-m3-bmw-m4-i...
Regarding the manifold design, I don't think it is materially different than the N54.
Other theories ?
Nanook said:
The Skyline (RB20/25/26 i.e. the straight 6) and the Supra fire 1 5 3 6 2 4
The S55 in the BMW M4 fired 1 3 5 6 2 4.
Will make a bit of a difference to how it sounds, but probably not that much.
Not if it has two branches of 3 exhausts coming off the block. It'll sound materially the same that way.The S55 in the BMW M4 fired 1 3 5 6 2 4.
Will make a bit of a difference to how it sounds, but probably not that much.
It'll all be in the exhaust design, and the valve timing.
t as well compared to the 1JZ's and RB26's I have owned imo. The only nice sounding turbo-charged engine I can recall is the Subaru WRX. Everything else is variations of crap.
I suspect BMW doesn’t even try. They’ve gone for the MP3 solution so ptobdnly see no point in worrying about the actual sound.
BMW used to make great sounding cars/engines with what seemed like a lot of pride. I don’t know where it all went wrong.
I suspect BMW doesn’t even try. They’ve gone for the MP3 solution so ptobdnly see no point in worrying about the actual sound.
BMW used to make great sounding cars/engines with what seemed like a lot of pride. I don’t know where it all went wrong.
It’s a question I always ask, the 35i/40i engines sound sublime, perfect in fact and the F8x M engines sound crap when compared.
They just make a really loud noise, sort of like a back box on a 1.4 polo.
It wouldn’t stop me from buying one as the M4 really is a stunning car in every way, the noise does let it down but it’s not an unpleasant noise, just a loud one with nothing about it like a C63 or anything.
It’s the same thing with M5’s and M6’s, just nothing about the noise what so ever!
There must be a logical explanation
They just make a really loud noise, sort of like a back box on a 1.4 polo.
It wouldn’t stop me from buying one as the M4 really is a stunning car in every way, the noise does let it down but it’s not an unpleasant noise, just a loud one with nothing about it like a C63 or anything.
It’s the same thing with M5’s and M6’s, just nothing about the noise what so ever!
There must be a logical explanation
Nanook said:
If by 'materially the same' you mean, 'a bit different', then I agree.
One of those orders fired out alternate exhausts every time. The other doesn't.
Like, a beetle sounds nothing like an Impreza, even with equal length manifolds.
BMW N54 twin turbo - nice soundOne of those orders fired out alternate exhausts every time. The other doesn't.
Like, a beetle sounds nothing like an Impreza, even with equal length manifolds.
BMW S55 twin turbo - poor sound
Both are 3.0L (2979cc) inline sixes with separate 3-into-1 (turbo) exhaust manifold designs. I assume they share the same firing order.
I am still confused.
airiscool said:
BMW N54 twin turbo - nice sound
BMW S55 twin turbo - poor sound
Both are 3.0L (2979cc) inline sixes with separate 3-into-1 (turbo) exhaust manifold designs. I assume they share the same firing order.
I am still confused.
S55 is twin scroll single turbo is it not (based on the N55 not N54)BMW S55 twin turbo - poor sound
Both are 3.0L (2979cc) inline sixes with separate 3-into-1 (turbo) exhaust manifold designs. I assume they share the same firing order.
I am still confused.
(Just googled it and turns out it has two mono scroll turbos. Didn't know that)
Edited by Dannbodge on Saturday 10th November 17:48
The exhaust design does make a big difference. The standard downpipes will usually be different lengths as the turbos are positioned one behind the other.
There are aftermarket options for equal length downpipes from various tuners such as this one from Mines for the RB26:
It's what results in the distinctive high pitched howl: http://www.youtube.com/watch?v=Bfd6yHjkW6k#t=102
I changed to the mines downpipe above this year and it made a big difference. Maybe someone does an aftermarket solution for the S55?
There are aftermarket options for equal length downpipes from various tuners such as this one from Mines for the RB26:
It's what results in the distinctive high pitched howl: http://www.youtube.com/watch?v=Bfd6yHjkW6k#t=102
I changed to the mines downpipe above this year and it made a big difference. Maybe someone does an aftermarket solution for the S55?
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