What is it about those exotic engines?

[Guest l28et]

I don't mean to steal this thread ' date=' but I still get goose bumps when I hear this Z06, You can just feel the high compression of that motor!

http://videos.streetfire.net/search/z06/9/CDD25771-FFE9-445D-8664-DACB2ED3C957.htm.

 

Sounds like pop corn popping at idle.

[cygnusx1]

Oh yeah, how could I forget my third favorite sounding engine...the WRX's and the STi's. I drive one. Here is a video I took at the New York Rally of one of the teams. You can distinguish a Subaru sound anywhere. They have an animalistic DEEP growl almost like an angry beast.

 

http://album.hybridz.org/data/500/Movie.wmv

[fastzcars]

O.k. back to exotic motor sounds, how about a porche GT?http://videos.streetfire.net/category/Porsche/2/ff5a62c2-8bd1-4740-bd4c-03eba7c82136.htm.

[col]

prOxalmus you have got me thinking and im not sure if i fully understand your pulse diagrams if i understand corectly, I dont understand why any engine is odd fire.

Ive heard v8's with crosovers(or what you call 180 deg headers) in my opinion these pipes give a higher reving more exotic sound.I would imagine an engine with an even fire engine with flat crank or 180 deg headers could then be compared to a 4 cyl doing twice the revs.this would explian the more exotic sound please correct me if im wrong. col

(what benifit does an odd fire have)

[JustinOlson]

Dont forget the audi 5 cylinder. They are great sounding motors

 

http://video.google.com/videoplay?docid=6369021561677387492&q=audi+turbo

 

Thats what I have in my audi project and am building a high reving version to put into my datsun

 

Heres my audi at this point:

[boodlefoof]

you can also even out the exhaust pulses by running a set of 180 degree headers, this will essentialy do the same thing to the exhaust note a flat plane crank

 

Yup, what he said. I'm going to see if I can fab and fit a pair of 180 degree headers in my project.

[Moridin]

Lots of Ferraris have V8s with a flat crank. Totally different sound than a domestic V8 (different firing order).

 

Fires two cylinders at a time if I remember correctly which creates the higher pitched sound.

[proxlamus©]

i agree .. the Audi Quattro S1 in the Group B rally days sounded AMAZING!!

[2126]

Heres an observation on why one engine sounds different than another.

Think about the diameter and volume of the cylinders, number of cylinders, and intake and exhaust runner lengths and diameters. In the world of acoustics, a smaller diameter and or volume device will provide a higher frequency responce than does a larger diameter and or volume device. Some food for thought!

[Gollum]

Yes, but if you watch the vid of the 1UZFE with ITB's it has a deep growl that you can hear behind the sound of the intake. This has been a big discussion between me and car friends lately, becuase honestly I don't understand alot of it and truly don't know how much everything contributes.

 

But lets look at this, what creates noise in a motor? Friction, air movement, and combustion. An explosion will always create noise, and more pressure = different noise. So a higher compression motor will have a different sound from the same exact motor with a lower compression. Now there's definately intake noise that really contributes to the engine tone that's emitted from the engine bay, but that should have much influence in the exhaust note.

 

Now, the odd fire V6 thing. I thought this was due to the fact that 2 cylinders must share a crank posision and 360 doesn't get divided by 6 very well. You could give each cylinder it's own bearing on the crank but that would weaken the bottom end becuase it would have to be a thinner more seperated crank.

 

Now, 180 degree or 90 degree crank, a V8 will still fire one cylinder per 90 degrees of crank rotation. Yes you could make two pistons fire at once, but why when you can have 8 evenly spaced fires even with a 180 degree crank.

 

Intake is something I wouldn't have given much credit to a month ago in contribution of engine sounds, but you can easily hear the intake on a ITB car going down the track admists all the noise of exhaust. You have to consider that the air going into the motor is going in under some serious pressure so the air is going to make noise no matter what.

 

Turbos will obviously have a bg contribution on noise even without the wistle of the turbo. All the exhaust has to go through the compressor so it HAS to change the sound of the exhaust.

 

Also notice that the vid posted earlier of a ferarri has a redline of 8k and it still sounds remarkibly similar to a F1.

 

http://video.google.com/videoplay?docid=-3747528804485007709&q=Ferrari

 

Is it the piston size combined with insane piston speed that creates that noise? I mean, a tiny go-kart still sounds like a lawn mower, not a F1. So even simple piston size isn't all of it. Granted go-karts are usually 2 stroke i'm just pointing out there are SO MANY variables to count here. As far as I know (but this isn't solid information) F1 cars tend to run short stroke, high bore motors, wich is largely what allows so many RPM. Makes sense, but many ferarris have small piston'ed V12 motors with quite long strokes compared to bore.

 

So what I'm getting at is that this has bee a big topic for me lately, and I have yet to figure out an ouce of it.

 

I doubt that really helped anyone...

[Clifton]

 

Also notice that the vid posted earlier of a ferarri has a redline of 8k and it still sounds remarkibly similar to a F1.

 

http://video.google.com/videoplay?docid=-3747528804485007709&q=Ferrari

 

Is it the piston size combined with insane piston speed that creates that noise? I mean' date=' a tiny go-kart still sounds like a lawn mower, not a F1. So even simple piston size isn't all of it. Granted go-karts are usually 2 stroke i'm just pointing out there are SO MANY variables to count here. As far as I know (but this isn't solid information) F1 cars tend to run short stroke, high bore motors, wich is largely what allows so many RPM. Makes sense, but many ferarris have small piston'ed V12 motors with quite long strokes compared to bore.

 

So what I'm getting at is that this has bee a big topic for me lately, and I have yet to figure out an ouce of it.

 

I doubt that really helped anyone...[/quote']

 

Don't know of any Ferrari engines that have longer stroke than bores but I think the single plane crank attributes to most of the sound, comparred to dual plane V8's that sound like Harleys. Even Vipers use single plane cranks and they sound good even though they don't rev high and have a super long 99mm stroke.

[Gollum]

I think the crank will have a large impact on the texture of the sound yes, but I don't think that's what will make the difference between whiny and beefy sounds. If you took a SBC and put in a 180 degree crank I don't think it will automatically start sounding like an F1 car. I think it will rev smoother sounding and have an overal more harmonic sound, but it probly won't change the overall pitch and such of the sound.

 

Just a couple weeks ago I saw a guy at a car show who build a 1/3 scale 350 SBC that actually runs. Pretty cool. It sounded like a 350 chevy that had an audio clip that was sped up, in other words it sounded identical but higher pitched. Now, if you put a 180 degree crank in THAT motor we might be getting closer to that F1 sound. Now put on equal length headers, and some nice ITBs and it will REALLY scream.

 

And i'm not really positive about all ferrari engine specs, but I know the lambo mercialago is 88 bore 89 stroke, but it sounds deeper and more mean than ferrari's.

 

EDIT: Go here and click V8 Video

 

http://www.weberprecision.com/

 

Pretty cool but you'll see what i'm talking about. Sure it's all high pitched but it still sounds like an american V8, wich very well is probly the crank design.

[CruxGNZ]

Don't forget about valve overlap. This contributes to some of the 'intake' noise heard on n/a engines.

[2126]

I believe all that you guys have mentioned certainly contribute to the overall sound of an engine. The point I'm trying to get across may be explained by the following example.......think about why a trumpet sounds different than a tuba! One has more volume and larger diameters (tuba) than the other (trumpet). What do ya think?

[Gollum]

Yes, but then a brass player might use a mute. Then you've got room dynamics, and you've also got lip pressure and other variables of the player.

 

I agree, a certain siz piston will create a certain sound, but there's just so much more that goes into it that when you've got thousands of fires per minute one single influnce on the sound just gets blended in with all the other noises the motor makes.

[2126]

Gollum,

 

I'm not interested in getting into a contest on this subject, just trying to provide some education based on many years in the world of professional audio. As I mention in my previous posts....I agree that there are many many variables that will alter the root frequency but the basic tone has to do with the size and volume of where the sound comes from and what it propigates through. Another major factor in the tone of an engine is the frequency of the events (RPM).

[Gollum]

Sorry, I didn't want to make it an argument, just simply trying to make sure we're all in agreement in some shape or form.

 

An analogy that probly won't work for many people, is the guitar, one that I think about myself for my own analogies. Between electric, acoustic, nylon, and the thousands of amps there are near infinante sounds possible for guitarists, even 2 guitars with the same guage strings set to the same tunning can sound totally different.

 

Anyways, that's just something I think about whenever I think about engine sounds.

 

Anyhoo, lets continue the light hearted talk shall we?

[2126]

Sorry' date=' I didn't want to make it an argument, just simply trying to make sure we're all in agreement in some shape or form.

 

An analogy that probly won't work for many people, is the guitar, one that I think about myself for my own analogies. Between electric, acoustic, nylon, and the thousands of amps there are near infinante sounds possible for guitarists, even 2 guitars with the same guage strings set to the same tunning can sound totally different.

 

Anyways, that's just something I think about whenever I think about engine sounds.

 

Anyhoo, lets continue the light hearted talk shall we? [/quote']

 

I agree! I believe we both understand the variable in the equation. One good thing in debating with you is that you do think out-of-the-box....a good sign of a creative imagination! FYI, and this was years ago, I played, wrote, and sang in rock bands (70's)....a drummer I am! Like Ted once said...."Keeping the beat, down in the seat, with her hand".

[Moridin]

Well, everyone pretty much agrees that there are a bunch of different variables that go into what an engine sounds like, right? I would say there is an order of importance. At the top of the list, for me, is number of cylinders, firing order, flat crank or not, compression (dynamic and static), and displacement.

 

What do you guys think?

[Gollum]

I might reverse compression and displacement, but that's maybe.

 

And the number of cylinders seems to make a largest difference in how smooth a motor sound. Like a honda always sounds harsh in a way compared to a V12 or F1 but has some similarities. I assume this is due to the fact that there's just less pistons making that sound.

 

I'm not saying that's not a HUGE difference, and I think that's probly a big part of what makes exotics sounds so amazing. But now i come to a guitar analogy

 

One guitar playing something can sound cool, but double the track and now it sounds much fuller and richer. Same sound but much better. Take an engine and double the pistons and yes it's a VERY different sound, but I can't see that being the #1 contributor to say, the sound of an F1.

 

If it seems like i'm posting alot in this thred it's just becuase I REALLY like this topic and it facinates me and I want to learn more.

 

But maybe I should try to figure out what 'I' think is the top contributors to engine sounds so you guys can debunk me