I have always been wondering but... (two questions)

[Ferrari458Italia]

1) Why is it that American cars are usually almost always supercharged while Imports are almost always never supercharged but rather turbocharged??? why does say Chevy never turbocharges their Camaro and why does say Subaru doesn't supercharge their STI?


2) Why makes a Ferrari V8 sound so much different than a say Mustang V8?? what component in the engine changes the tune of the exhaust around??

I've always been wondering about these two. As much as I wish I knew a lot about cars mechanically, I just don't

 

[Slash]

1) Why is it that American cars are usually almost always supercharged while Imports are almost always never supercharged but rather turbocharged??? why does say Chevy never turbocharges their Camaro and why does say Subaru doesn't supercharge their STI?

Because they want to?

2) Why makes a Ferrari V8 sound so much different than a say Mustang V8?? what component in the engine changes the tune of the exhaust around??

Different engine block designs, sometimes overhead cam/overhead valve designs, different firing orders, different cam profiles, crossplane crankshaft vs flat plane crankshaft, changes in timing...lots of differences.

 

[Joey D]

Engine size has an influence on either doing a turbo or supercharger. American and German engines tend to be on the larger side, or at least they did, and Japanese engines tend to be smaller in size. Since superchargers are less efficient and require the engine's power to spin the compressor, it makes more sense to put them on a larger engine where the effects will be less noticeable. Turbos don't require the engine's power so having them on a small engine allow the power to be the most maximized for the application.

This is changed now since for the most part American engines are starting to become turbocharger since turbos are the better choice from an engineering standpoint.

As for your second question about the sound of the engines, RPMs, the intake system and exhaust system (headers, pipes, muffler, resonator, etc.) are the biggest contributors to the change in tone. Also Ferrari engines tend to be smaller than traditional American V8's, although not really that different anymore I suppose, so that changes the sound too.

 

[Rage Racer]

1) Why is it that American cars are usually almost always supercharged while Imports are almost always never supercharged but rather turbocharged???

Uhm... What about Range Rovers, Jags, Astons, Mercedes?..

And, you're definetly generalizing about "American cars are usually almost always supercharged"...
You propably mean if they aren't naturally aspirated. Then yes, supercharger is a lot more common type of charger on them.

 

[Ferrari458Italia]

Uhm... What about Range Rovers, Jags, Astons, Mercedes?..

And, you're definetly generalizing about "American cars are usually almost always supercharged"...
You propably mean if they aren't naturally aspirated. Then yes, supercharger is a lot more common type of charger on them.

what about Range Rover, Jags, Aston, etc?

and yeah I that's exactly what I meant. I didn't mean to say every single American car is supercharged lol.



@Joey D I gotcha. that's some good points! thanks bud!

 

[Ken]

what about Range Rover, Jags, Aston, etc?

Those examples are usually supercharged. Which negates your "American only supercharges".

 

[Ferrari458Italia]

Those examples are usually supercharged. Which negates your "American only supercharges".

gotcha. well I just used american and japanese cars as example. obviously there are way more different kind of cars in the world

 

[McLaren]

I asked a question similar to your 2nd several, several years ago. A couple from then:

Years ago, as JNasty already put it, the sound was simply a by-product of the engineering choices. Basic architecture and design of the engine dictated the sounds it would make. If you think about it, the sound an engine makes is simply a series of exhaust pulses which run along a narrow metal tube and the purely mechanical noises made by the reciporcating parts within the block-- combined with anything (if at all) that escapes from the intake tract.

These days, I believe almost all performance cars have exhaust sounds engineered into them. I remember reading when the water cooled 996 was introduced that Porsche actively worked to recreate the old air cooled sound that was distinctive of the 911. A lot of it was exhaust work, but I'm sure there was sound tuning made at every level in the development.

The Dodge SRT-10 engineers made the sipe pipes of the Viper an "H" pipe that connected in the middle so that you could hear all 10 cylinders, instead of just 5 on the old sidepipe models, just to avoid having the car sound like a UPS truck.

The BMW Z4 has a plastic resonator --a sub-woofer, if you will, that physically connects the intake manifold with firewall ahead of the dash, in order to "pipe in" engine noise because otherwise it wouldn't make it past the sound deadening in the passenger compartment.

But all in all, I think most sound tuning these days is done at the post-cat phase, within the muffler itself, though I'm sure there is plenty of header/downpipe/pre-cat work too.


M

Well, as M5 and I both described, now a days, its more a result of "MAKING" the engine sound a certain way, rather than just let it happen. Back in the day, when the designs of engines were a bit of a black art, you would see all sorts of designs and styles of engines. All of which would have a different sound. Then, as certain cars became more "known" for a certain sound, the company would try to get the new cars to still make that sound.

As M5 stated, when Porsche switched from the air-cooled engine to the water-cooled engine in the 996, they did a heavy ammount of work to get the exhaust and intake sound distinct and still have that "Porsche" feel.

Same goes for Subaru. Like I said earlier, the reason the boxer engines in a WRX sounds so funky compared to other engines is the fact that the header tubes are un-equal length. The exhaust pulses from each side of the car get from the heads to the turbo, and then out the car at different times. But, on the Spec-C car, they actually use an equal-length header on it, thus making it sound like every other 4-cyl car out there. That design can work better in some circumstances because of the "scavenging" effect on the exhaust. But either way, the Spec-C STi sounds nothing like a normal Suby because of it.

And, also like what M5 said, and similar to the Suby sounds, the design of a V-shape engine's exhaust is very distinct. On early Vipers, with the side pipes, many of the aftermarket exhaust solutions were just high flow units that didn't have an X-pipe. They would just have 2 banks of 5-cyls running off the engine, and then out the side of the car. Thats all well and good when stock. But not once you put an aftermarket exhaust on that has much louder sound and higher flow. The cars would end up sounding like they had real high strung 5-cyl engines in them. Not that good. Same goes for just about every V engine out there. They will almost always use some form of X-pipe to balance out the exhaust pulses to get the car sounding correct.

But overall, the sound of cars these days is all science. Back in the day, it was just the byproduct of innovative or unusual design. But now, with the computer simulation and ease of engineering processes, they can make a car sound pretty much how ever they want.

Hilg

 

[Space Dynamics]

The Ferrari sounds so much different from the mustang because one is a flat plane v8 while the other is cross plane. I know it's already been answered, but that is the main distinguishing factor for sound.

http://www.autozine.org/technical_school/engine/smooth4.htm#V8

 

[Famine]

1) Why is it that American cars are usually almost always supercharged while Imports are almost always never supercharged but rather turbocharged??? why does say Chevy never turbocharges their Camaro and why does say Subaru doesn't supercharge their STI?

[Generalisation'o'clock]

Americans like big torque, low down. Japanese like big power, high up.

Superchargers are driven off the crank and take power lower down before they make it, so having big torque to drive them is good. Turbochargers are driven off high velocity exhaust gases and make power as you give it to them, so having power high up is good.

2) Why makes a Ferrari V8 sound so much different than a say Mustang V8?? what component in the engine changes the tune of the exhaust around??

The crankshaft.

In a flat-plane crank, if you lay the crankshaft down, all the crank pins go left or right. This means that the cylinders fire in pairs. In a cross-plane crank, half the crankpins go left or right, the other half up or down. This means that the cylinders fire individually.

 

[Ferrari458Italia]

[Generalisation'o'clock]

Americans like big torque, low down. Japanese like big power, high up.

Superchargers are driven off the crank and take power lower down before they make it, so having big torque to drive them is good. Turbochargers are driven off high velocity exhaust gases and make power as you give it to them, so having power high up is good.The crankshaft.

In a flat-plane crank, if you lay the crankshaft down, all the crank pins go left or right. This means that the cylinders fire in pairs. In a cross-plane crank, half the crankpins go left or right, the other half up or down. This means that the cylinders fire individually.

great stuff. thanks man!


& thanks to everyone else. I understand now

 

[Slash]

@Famine

A lot of it based on the crankshaft but there's many other factors that were mentioned that change the sound.

A trained ear can tell a Chevy V8 from a Mopar, AMC or Ford one for example. Or even its own brothers and different designs. There's many factors.

 

[homeforsummer]

A lot of it based on the crankshaft but there's many other factors that were mentioned that change the sound.

A trained ear can tell a Chevy V8 from a Mopar, AMC or Ford one for example. Or even its own brothers and different designs. There's many factors.

Except the OP wasn't asking that. He was specifically asking what makes a Ferrari V8 sound different from [insert generic American V8 here]. While there are other factors, the vast difference in sound between say, a 458 and a Mustang, is primarily dictated by the difference between the flat-plane and cross-plane cranks.

Most of the other factors are a symptom of that main difference.

 

[Slash]

In actuality he kind of did. All of that stuff dictates what an engine sounds like.

The crank is the biggest of the bunch, but to an untrained ear at low RPM's they don't sound all that different.

 

[homeforsummer]

but to an untrained ear at low RPM's they don't sound all that different.

No, 'course not, they're basically identical...

​

Even an "untrained ear" can tell the Mustang has a much deeper tone just idling - the Ferrari sounds more like an aggressive four-cylinder until there's some revs on it. And at anything above idle, the Ford has that characteristic "burble", where the Ferrari takes on a much harder-edged sound.

And those are relatively modern, homogenized versions of their predecessors. There's even greater difference between, say, a Ferrari 308 and a 1960s Mustang.

You're right - lots of things dictate the sound of a car, not least the design of the exhaust itself. But the main difference between the characteristic lumpy burble of a 'Murican V8 and the mechanical wail of a Ferrari V8 is the wholly different firing characteristics dictated by the shape of the crank. You could piss about with exhausts, fueling, manifolds and whatever all you like but you can't make a Mustang sound like a Ferrari, or vice-versa.

 

[Celicaas]

Is it me or The car sounds Diffrent When you rev it while stationary and sounds Diffrent when you are driving it hard on ?

 

[Slash]

It does, because there's a load or stress on the engine to push all that weight forward.

I love the sound of an American V8 under load. Sounds way cooler than just sitting there revving it.