BMW M4 sounds bad. M2, Supra, Skyline are wonderful - why?
Discussion
I’ve just been out for a bomb round in the M4 with this thread in mind.
First of all, you can drive the car gently around town with the back exhaust box switched in and all this extreme “popping and farting” doesn’t happen if you don’t want it to. If you insist on using bigger rpm on the overrun then yes, it does indeed crackle it’s head off. But to suggest that you can’t control that is plain wrong. If your M4 is making itself heard then I suggest that’s you doing a “oh I wish it wouldn’t do that but look at me” scenario.
There is a guy I know at my gym with an M3 to which he has had the sports bmw exhaust fitted. That one really is loud but, since it is an option you don’t have to choose it. Also, my first M4 (a non comp model) hardly did ANY crackling at all even when provoked. The comp model has a slightly different exhaust (sort of half way between non comp and “m power accessory catalogue” sport one) and if you want it to you can indeed make a racket.
Having said all of this, I have a different mind set than you guys with the car. I grew up seeing the big turbo cars in motorsport and when everything went naturally aspirated I was gutted. I remember waving goodbye to the Renault 5 GT Turbo as a model and although I loved my 16v Clio it was simply never as visceral as the old car. The Zetec Fiesta RS1800 and escort RS2000 were miles better than the CVH RS Turbo’s but I bet the turbo cars left more of an impression on you.
Turbo cars have always been about explosive power, crazy noises, flames and enormous amounts of torque. I love the sound of a NA six but is there not room for us to appreciate an engine for its all round stellar performance rather than writing it off because it doesn’t play orchestra?
If you can find somewhere clear enough to open the M4 up and run it through the gears and actually tax the thing through a series of heavy braking and heavy accelerating corners then actually it sounds pretty dramatic. Of course, around town and on dreary 40mph sat in endless A road traffic it sounds just as dreary as the road but give it a chance!
It won’t win any sound awards but if you think of it as a bit of a homage to the old school big turbos rather than a development of the traditional NA BMW six then you’ll probably find it easier to reconcile and live with.
Edited to add - I’ve rather missed the point of this thread haven’t I? That the M2 sounds good even WITH its big turbo but the M4 doesn’t! Haha. Sorry chaps. Guess I need to...
First of all, you can drive the car gently around town with the back exhaust box switched in and all this extreme “popping and farting” doesn’t happen if you don’t want it to. If you insist on using bigger rpm on the overrun then yes, it does indeed crackle it’s head off. But to suggest that you can’t control that is plain wrong. If your M4 is making itself heard then I suggest that’s you doing a “oh I wish it wouldn’t do that but look at me” scenario.
There is a guy I know at my gym with an M3 to which he has had the sports bmw exhaust fitted. That one really is loud but, since it is an option you don’t have to choose it. Also, my first M4 (a non comp model) hardly did ANY crackling at all even when provoked. The comp model has a slightly different exhaust (sort of half way between non comp and “m power accessory catalogue” sport one) and if you want it to you can indeed make a racket.
Having said all of this, I have a different mind set than you guys with the car. I grew up seeing the big turbo cars in motorsport and when everything went naturally aspirated I was gutted. I remember waving goodbye to the Renault 5 GT Turbo as a model and although I loved my 16v Clio it was simply never as visceral as the old car. The Zetec Fiesta RS1800 and escort RS2000 were miles better than the CVH RS Turbo’s but I bet the turbo cars left more of an impression on you.
Turbo cars have always been about explosive power, crazy noises, flames and enormous amounts of torque. I love the sound of a NA six but is there not room for us to appreciate an engine for its all round stellar performance rather than writing it off because it doesn’t play orchestra?
If you can find somewhere clear enough to open the M4 up and run it through the gears and actually tax the thing through a series of heavy braking and heavy accelerating corners then actually it sounds pretty dramatic. Of course, around town and on dreary 40mph sat in endless A road traffic it sounds just as dreary as the road but give it a chance!
It won’t win any sound awards but if you think of it as a bit of a homage to the old school big turbos rather than a development of the traditional NA BMW six then you’ll probably find it easier to reconcile and live with.
Edited to add - I’ve rather missed the point of this thread haven’t I? That the M2 sounds good even WITH its big turbo but the M4 doesn’t! Haha. Sorry chaps. Guess I need to...
Edited by Julian Thompson on Sunday 11th November 19:03
As above, headers and exhaust can do wonders for the sound.
Here's an example:
Stock E46 M3 a.k.a 'The Chainsaw':
https://www.youtube.com/watch?v=0ViQq3sU7HM
E46 M3 with Custom Headers and Supersprint exhaust:
https://www.youtube.com/watch?v=6jRxtmi61aI
Here's an example:
Stock E46 M3 a.k.a 'The Chainsaw':
https://www.youtube.com/watch?v=0ViQq3sU7HM
E46 M3 with Custom Headers and Supersprint exhaust:
https://www.youtube.com/watch?v=6jRxtmi61aI
GroundEffect 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.
That's a significant change if the firing order is 135624. 99% of I6 motors use 153624.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.
So a twin turbo like these would normally fire
1 - bank 1
5 - bank 2
3 - bank 1
6 - bank 2
2 - bank 1
4 - bank 2
That gives perfect alternating firing pulses to each turbine in turn and also pulses from each tailpipe where dual exhausts are used like N54 etc.
However, 135624 is
1 - bank 1
3 - bank 1
5 - bank 2
6 - bank 2
2 - bank 1
4 - bank 2
Very different indeed...... two pulses in turn to bank 1 then two to bank 2, then 1 pulse each then back to the twin pulses......
Think thats the reason.
mikeN54 said:
GroundEffect 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.
That's a significant change if the firing order is 135624. 99% of I6 motors use 153624.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.
So a twin turbo like these would normally fire
1 - bank 1
5 - bank 2
3 - bank 1
6 - bank 2
2 - bank 1
4 - bank 2
That gives perfect alternating firing pulses to each turbine in turn and also pulses from each tailpipe where dual exhausts are used like N54 etc.
However, 135624 is
1 - bank 1
3 - bank 1
5 - bank 2
6 - bank 2
2 - bank 1
4 - bank 2
Very different indeed...... two pulses in turn to bank 1 then two to bank 2, then 1 pulse each then back to the twin pulses......
Think thats the reason.
S55 although is my least favourite sounding BMW turbo I6, it doesn’t sound too bad here:
https://youtu.be/eE8yikDPI7E
Still prefer it to the V8 of the C63 (I am probably in the small minority here!).
https://youtu.be/eE8yikDPI7E
Still prefer it to the V8 of the C63 (I am probably in the small minority here!).
Edited by AI1694 on Saturday 30th March 22:13
AI1694 said:
S55 although is my least favourite sounding BMW turbo I6, it doesn’t sound too bad here:
https://youtu.be/eE8yikDPI7E
Still prefer it to the V8 of the C63 (I am probably in the small minority here!).
That looks about at uneventful as watching paint dry. shttps://youtu.be/eE8yikDPI7E
Still prefer it to the V8 of the C63 (I am probably in the small minority here!).
Edited by AI1694 on Saturday 30th March 22:13
t exhaust noise, stupid gear change fart, no induction howl, no manual gearbox, steering probably devoid of feel... This is an M car. Where's the driver involvement? Where's the sense of occasion?
AmosMoses said:
Firing order will indeed be the cause. I cannot stand how the new M3/M4 sounds, it’s just terrible. It’s up there with the 718 as the worst sounding car on sale.
A bit harsh - I love the S55 in my M2C, even with OPF - bit the Milltek system waiting in the garage will help 
After looking at crank shaft images from S55 and N55, they are the same crank pin layout therefore the S55 firing order cannot be 135624, it has to be 153624 as N55 and as other I6.
It can only be 153624 as that follows the crank pin sequence to TDC and fires at alternate ends of the motor.
Each firing stroke on an inline six is 120deg apart, (i.e. a 3rd of a rotation = 720deg / 6), but crank pin 3 is 240deg behind crank pin 1, so 3 cannot follow 1 under any circumstances.
Only 5 or 2 can follow 1 on this crank layout.
It could physically be 124653, but that is completely unheard of and not balanced end to end.
S55 has no balancer shafts so the standard 153624 sequence assures perfect balance.
Looks like the sound issue is likely not to do with firing order .....
S55 crank https://www.realoem.com/bmw/enUS/showparts?id=2U72...
N55 crank https://www.realoem.com/bmw/enUS/showparts?id=UV92...
S55 https://www.ebay.co.uk/itm/REFURB-CRANKSHAFT-CRANK...
N55 https://www.ebay.co.uk/itm/ENGINE-CRANKSHAFT-BMW-N...
Edited by mikeN54 on Sunday 31st March 19:09
DMZ said:
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.
Noise regulations.. EU?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.
deltashad said:
DMZ said:
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.
Noise regulations.. EU?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.
To be fair, the sound of the current M3/4 isn't great, but the way it fires you towards the horizon is. It's a super, super functional piece of engineering, if the brief was to create something unrelentingly effective. It just does exactly what it says on the tin. It's also very responsive for a turbocharged engine. It feels like your toes are tickling the inlet valves. It night be clinical and sound like a Dyson, but it hits the brief.
Gassing Station | General Gassing | Top of Page | What's New | My Stuff