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?
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:
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.
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