What makes Ferrari sound Ferrari?

I think the flat crank has a lot to do with it.

 

It's the flat plane crankshaft for sure.

 

Once upon a time, it was probably a mixture of the flat crank,the blend of mechanical whirrings, intake and exhaust noise. After all, all Ferraris, from the Dino 6 to the flat 12 all had a unique italian sound.

Much to my dismay, these days it is strictly exhaust tuning. Ferrari has an idea what they want their cars to sound like and tune the bejesus out of them to get them there.

Its not just Ferrari, for 10K kreissieg exhaust can make your Boxster sound like an F1 car...I'm just saying.

Much more annoying to me, however, is the latest fad of overrun sounds. In 2012 a Ferrari NEEDS to pop and burble on the overrun to make power...Really? Apparently, Mercedes didn't get that memo.

Quite frankly I find it annoying and I feel like I am being pandered to.

Ferraris used to have a form followed function quality to every facet of their engine design. Because most of the old engines were related in some manner to their existing race programs, they all just happened to sound delightful because they invoked the sounds of the cars of the Scuderia. There is no engineering reason for a modern Ferrari to sound anything like an F-1 car, of which they share virtually nothing engine wise.

 

for those that don't know the difference
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I also find it really annoying that they'd put a flat 12 engine OVER the gearbox negating any CG benefits the engine could provide. They only did it to say they put an f1 engine in a car, not for any performance reasons. No engineering reason at all to put a flat 12 engine in a road car unless you mount it inline with the gearbox, and looks like they learned from their mistake as all subsequent mid-engined cars (f1 included) have been inline with the gearbox (and v12's).

 

The sound is probably the main reason I bought a Ferrari. Performance matters too but if that's all I cared about I would have bought a GTR.

I had a girl in my 355 this weekend. It was her first time in a Ferrari. She complained that it was too loud and said she'd like the car more if it was quiet. I told her she was dumb and took her home. She's a friend of my wife so I think she took it as a joke. I was only halfway joking.

 

pitch of sound has to do with displacement / volume of the cylinders, as does diameter of exhaust,

number of cylinders has to do with the number of pulses per rotation of the crank, more cylinders increases the number of pulses per rotation and more interaction with other pulses

Timing ( as in crank configuration ) determnes when a pulse will occur and how it will interact with other pulses

rpm also influences sound

then there is what happens when all these pulses meet and collide... as in how exhaust and intake manifolds are designed for optimum power

sound engineers can totally cancel engine exhaust sound with other sound, or they can tune to a desired sound and level

there is a lot going on when an engine makes its' sound, some of which can be controlled

oversimplified engine displacement, number of cylinders, and rpm

 

A) The flat plane crankshaft makes both sides sound the same--like 2 4-bangers simultaneously firing out of phase. LRLRLRLR (4 evenly spaced beats) while the American V8s have an odd kiltered pulse train of RLLRLRRL this gives each side a 1:3 resonance (2 little beats with one large double beat) whereas the plat plane crank has a 1:4 resonance.

B) the headers and exhaust ports allow very high gas speeds (1500-1600 fps) this gas speed, when it runs into the still exhaust gasses in the collector and expansion chamber create the shriek.

C) The velocity stacks and helmholts resonators. These augment the exhaust gas shriek by filling out the higher parts of the audio spectrum with high levels of mid frequency gurgling noise.

D) Ferrari does not really care about keeping the noise lever way below standard dBs.

 

Yes, I'm one those that didn't know the difference. Thanks for explaining it. Now I'm curious about the firing sequence, does that mean that 2 cylinders are firing at the same time or nearly the same time???

 

If you recall, until the mondial t, all of Ferraris regular production mid engine cars had their engines atop ther transmissions. For whatever reason, Ferrari thought this superior from a packaging standpoint. If you've ever seen the contortions required to extract the engine and tranny from a countach, it might explain their reasoning, however antiquated it appears now. IIRC, the choice of the flat 12 for the original boxer made great sense from an economy of resources standpoint as it did from a marketing one.

Just to clarify my previous post, my gripe is really focused on only the most modern Ferraris, in particular the FF and the 458. As I've stated in many a thread, the high watermark for Ferrari exhaust sounds was the 355 and the challenge stradale, I feel like they've been chasing that tune ever since, despite having engines with considerably larger displacement, and the latest iteration just sounds synthetic to my ears.

 

I think this was covered in the above posts, the flat crank makes the 2 separate headers give a more even sound compared to a 90deg. crank. Flat cranks were tried rarely in NASCAR from time to time(Geoff Bodine about 10 years ago) and it sounded like he was turning more revs, smoother sound.




Ago

 

The classic Ferrari 'sound' comes from a number of interacting elements that line up n a synchronized chorous.

First comes the flat plane crankshaft. This gives each cylinder bank an even firing order LRLRLRLR whereas the typical american V8 has an off kilter firing order LRLLRLRR. The even firing order means that the intake and exhaust pulses are also synchronized and evenly spaced.

Next comes the headers. These headers are tuned for the power band of the engine, not too big, not too small, not too long not too short. The headers cause much of the low frequency rumble from these engines by setting up a standing wave pattern of pressure pulses.

Next come the intake system. Here the air path is essentialy straight (e.g. no turns) that enables the air to flow into the cylinders with minimal resistance. The straignt air flow and low resistance enables the velocity stacks to be tuned with the header to broaden the power band.

As the intake valve opens (with the still open exhaust valve) air begine to travel into the cylinder even before the piston starts dwonward from the negative pressure wave from the header. As the intake valve closes, there is considerable momentum in the air flow. When this reaches the closed intake valve, pressure builds until a positive pressure pulse runs up the intake and velocity stack finds air at atmosphereic pressure and sends a negative pressure wave back down. This negative pressure wave runs into the intake valve and sends a negative pressure wave back up the intake and VS, causing a subsequent positive pressure wave. much of the high frequency music of these engines comes directly from this process.

Just under the resonance point of the header there are an even number of intake cycles so that when the intake valve opens there is already positive pressure and momentum to take the fresh charge into the cylinder (also) even before the piston starts downward. Just above the resonance point of the header there is another even cycle count in the intake puls train. There are generally 8 or 10 cycles on the low intake resonance and 8 or 6 on the high RPM intake resonance. These broaden the powerband of the motor.

Finally, the throttle plates are positioined at the center of the intake path and at anything less than WOT damp out even order harmonics in the intake resonance so one hears the primary, 3rd order, 5th order,... of the air movements turned into that sonorous chorous. Even order harmonics end up sounding like an amplifier with cross over distortion, while odd order harmonics sound like an amplifier cliping the peak. Any music buff will tell you that odd is much better than even in sound quality.

The modern V8 engines also employ a 2 stage set of resonators. The air box covering the intake tracks is tuned such that at header resonance a positive pressure wave is above each intake velocity stack just before the intake valve opens. The great rush of air into the cyclinder reinforces this 'standing' wave resonance. These are known as helmholtz resonators.

At the end of this resonator is a smallish tube leading to the largish air filter box. The size and length of this tube damp out the resonator standing wave such that the mass air flow sensor gets a nice smooth flow of air and can thereby be used to give precise control to the FI system.

The difference betewwen Ferrari systems and other manufactures, is that Ferrari works to get the sizes, volumes, and resonance points to actually line up and sing. Whereas others just get them close enough to deliver the power.
Nuf Said

 

So, do all Ferrari's have flat plane crankshafts, V8's and 12's?

 

No. Only the V8's have flat plane cranks. I remember reading on this board that you actually cannot have a flat plane V12 because of balancing issues.

 

No, but they all have the RLRLRL... alternate bank firing pattern.

 

I think that you got what you asked for, Paul Great question and a terrific and educational thread. It's been a pleasure to read.

 

This is quite an interesting thread to read through. I love this place...

 

I was too No two fire at the same time, but if I understand correctly,with the flat plane crank, the two opposing banks of cylinders are firing in truly alternating order. The workload is evenly balanced between the front and rear banks. In a transverse Ferrari V8 engine, think F-R-F-R-F-R-F-R

(F)ront Bank - (R)ear Bank

Pressure delivered to the headers is then balanced, among other things.

With a cross-plane crank, bank-to-bank sequence is mixed up.

 

I love this forum!!
its amazing to read and learn so much about things you take for granted, I always thought F. cars sounded different, and its the reason my stereo never gets turned on, but having great and knowing minds come together , is just brain candy for me.

thanks so much

 

Looking at the thread title I thought this was going to be a dumb thread. Turned out to be furthest from dumb that could be imagined. I've learned quite a bit.

Happy to know Ferrari is still mechanically reproducing the great sound as opposed to BMW using computer generated playback for the sound from the M5.

 

Pretty low don't you think. No class at all. Soundtrack for the car, who thinks up stuff like that?

 

And don't be surprised to learn one day that Ennio Morricone was consulted when shaping the helmholtz resonators.

 

Seriously?