Reproduce a Ferrari Sound

Could any one here make a class in how the ferrari make that high and nice sound :bow: from the engine, not the V12 60 Valv. I say the V8 or the old V6 I6 they made sound like music for my.
This sound don´t come only for the 4 small pipes they have OR YES.
There is any way to reproduce this sound in a Lt1 engine.
The B&B triflow in their web have a vette sound, this sound very high but was a Ls1 not like a ferrari but very nice sound.

advanced tech? Umm... No, & grammer? Umm.. no LOL.

As far as my understanding goes, the Ferrari V8s us a flat plane crankshaft (180º) and that is a big factor in their higher pitched sound.
There was an article in Design News magazine bout five years ago on "Why Indy cars sound the way they do". I remember alot of talk on the flat plane crank and bank-to-bank firing schemes.

All that aside, I'm sure Ferrari spends a great deal of time in exhaust design..... trying to achieve that characteristic sound.

-Mindgame

Originally posted by Mindgame
As far as my understanding goes, the Ferrari V8s us a flat plane crankshaft (180º) and that is a big factor in their higher pitched sound.
There was an article in Design News magazine bout five years ago on "Why Indy cars sound the way they do". I remember alot of talk on the flat plane crank and bank-to-bank firing schemes.

All that aside, I'm sure Ferrari spends a great deal of time in exhaust design..... trying to achieve that characteristic sound.

-Mindgame

Agreed.

I have a Corsa Touring catback on my C5. The sound vs. the Indy Pace Car edition is very different. Yeah, it's more like the "ripping canvas" sound of a Ferrari, but quieter.

A lot of the tuning is cancelling out the frequencies you don't want and leaving in the ones you want. IMO, the Ferrari sound has more of the higher frequencies and fewer of the lower "pushrod V8" frequencies. I suppose one could do a sound analysis of the Ferrari exhaust, then configure a SBC exhaust to emit the same frequencies. If you combine or mix the exhaust perhaps the flat crank sound isn't as important. Most flat crank or 180 degree headers on 2-plane crank V8s have two outlets without a mixing box (single muffler).

Corsa's tuning method is like a closed organ pipe: each pipe or chamber in the muffler cancels a given frequency based on the closed pipe's length. This can be done with pipes attached to the exhaust collector, or as Corsa does it, by partitions in the muffler making various length channels. The concept isn't new. It was used in the 60's.

Originally posted by bunker
advanced tech? Umm... No, & grammer? Umm.. no LOL.
I don't think we have any limits on grammar (or spelling :D ). Not everyone who posts here has English as a primary language. The are welcome to post.

Originally posted by Injuneer
The are welcome to post.

Yes, poor grammar and spelling is tolerable but those people who miss keys....... should be burned at the stake.:mad:

;)

-Mindgame

Originally posted by Injuneer
I don't think we have any limits on grammar (or spelling :D ). Not everyone who posts here has English as a primary language. The are welcome to post.

grammar

I love it!

I designed an inline muffler once for a school project. I didn't get to do to much testing with it, but you can also do inlines in a similar way. Change length of chamber, chamber diameter and then put them in different stages, ie go from small dia./short to a larger dia./long and so on. I ended the tube with supertrapp baffles to try and divert the sound away from where I knew the db mic was going to be placed. Would have worked but we ran out of time to fine tune it before the competition. Open without the supertrapp baffels ='d very loud right behind the car, with baffles it was pretty quite, step to the side and it got a little louder.

There are so many variables to mess with in an exhaust system to make it sound different/louder/quiter/appear to be quiet...that it could take you years to nail down a particular sound.

I think harley spent a lot of exhasust r&d time getting that german engine in the V-rod to sound as close to a standard V-Twin as possible given the radical change in engine design.

Thanks for the reply’s.
And yes English is not my primary language, I like to write here because are a very respectful forum and the best in advance tech, and in this way I can practice have fun and learn from people who want to share his knowledge to any one to have a question.
May this is not advance question but here is the place were you get the answers from people like Mindgame OldSStroker Injuneer and others expert.
So back to the post l read in some place, the Harley Davidson sound is copyright l don’t know if this is true but may they work in the exhaust like Ferrari do.
So is all relate to the exhaust and could be the little and thin pipes they used.

I dont know the howtos or whys, but a freind of mine went from Flowmasters to Magneflow mufflers on his 2000 GT mustang and the tone increased by several octaves. The higher pitch was night to day to the flowmaster. As a note the mufflers were within an inch of each other, so internal chambering and baffling had to be the culprit.

Well said Injuneer.

OldStroker makes a good point in regards to noise cancellation. By employing reactive and active noise cancellation (wave superposition), you could design an exhaust system which emits those desired frequencies.
The sound, to a great degree, is "tunable".

Take care

Originally posted by Mindgame
Yes, poor grammar and spelling is tolerable but those people who miss keys....... should be burned at the stake.:mad:

;)

-Mindgame
Ughhh..... Guilty as charged.

:(

Hey.... wait a minute! Shouldn't that be "...... poor grammar and spelling are tolerable...... "

:D :D

Somebody ought to try and control this thread...........

Originally posted by Farc
...So back to the post. l read in some place, the Harley Davidson sound is copyright. l don’t know if this is true but may they work in the exhaust like Ferrari do.


One of the reasons for the Harley sound is the uneven firing order, sometimes described as a "poTAto-poTAto-poTAto" sound.

Yes, a lot of time is spent by Ferrari making their distinct exhaust sound. As many people have discovered when they change their exhaust systems, getting a pleasing sound without having annoying resonances at some rpms while improving power is challenging. Often those resonances show up from about 1500-3000 rpm, right in the cruising range for most cars.

One of the things you can accomplish with "organ pipe tuning" or RSC (Reflective Sound Cancellation) as Corsa calls it, is very quiet exhaust when the flow is low like during part-throttle cruise, and then more noise at high flow, high power, high rpm operation. That's my kind of exhaust. Here's a link to Corsa's explanation.

CORSA RSC explained (http://www.corsaperf.com/arsctech.htm)

Corsa does the tuning inside the muffler, but you could build your own LT1 system by welding "branches" onto your straight-through exhaust pipes and adjusting their length to tune the sound to what you like. (Ferrari?). The branches could be a lot smaller in diameter than the exhaust pipes, say 1-3/4 inches, and can join at 90 degrees because there is no flow in them, just sound waves bouncing back and forth. In fact, one of the Corsa mufflers has two 90 degree "branches" which disappear into a case. The tuning branches can have tight bends to fit them in the chassis.

If you try this, you probably want to consider an H-pipe if you plan true duals, or do all the tuning after the Y. Remember you won't need any muffler cases, so a true dual over-the-axle system may fit fairly well. You could also adapt a 3-1/2 inch single system with the muffler completely eliminated.

There may be some advantage to locating the "branches" at high pressure nodes along the exhaust pipe, but that is not necessarily mandatory.

Yeah, I've seen this done a long time ago by an OEM. The only production use was as resonators in the tailpipes, I believe. Corsa "resurrected" the concept. Good for them. I hope they gave credit to the engineer who did a lot of the pioneering work on it.

Good luck Farc, and don't worry about the grammar police. :)

Good post, OldSS. The OEM was Arvin. It was in the '60s. Put a closed pipe off the main exhaust pipe and tack it further down so it runs parallel. Arvin called it the Arvinode. It was a simple quarter-wave tuner. It's very effective at targeting a single frequency band. A Helmholtz tuner is a similar concept, with a volume combined with the tube. It widens the attenuation band and works better.

I don't think Harley was successful in receiving a patent for their sound. I think the Patent Office realized how stupid the idea was. I could be wrong, but I don't think so.

Exhaust tuning is 1 part science and 1 part black art. The guys who are really good at it have been doing it for years. They can look at an engine and pipe configuration and give the OEM an 85% good solution on the first try from prototype. The money is in the remaining 15%. Computer simulations are lucky to get halfway there on the first try.

Lots of things influence the sound coming out the tailpipe such as: Engine configuration (more cylinders, higher firing frequencies), pipe diameters, pipe lengths, unequal primary lengths (worst case is some cast manifolds), unequal y-pipe lengths, distance to silencing units, and of course, muffler volume and configuration (plus any number of other things). OEMs target a particular sound and engineer the exhaust for what they've got.

One thing that sticks out as particularly relevant for Ferrari is that there is minimal pipe length from the engine to the silencing unit. Mid-engine setups have that problem. It's important because the pipe length influences how effective the muffler is. Too little and the muffler isn't in the right place for problem frequencies. The Ford GT is a nightmare to tune because of this. I don't know exactly what the Ferrari setup looks like, but I can guess a little. Relatively small displacement, high-revving V8, longitudinally mounted, tubular headers (probably close to equal length), short intermediate pipes (again, close to equal length) into a tuned, stamped muffler. Tune the muffler for lower frequencies and not the higher ones, so when you rev, you've got the full sound in the upper RPM range. Result is higher frequencies predominate, the odd-sounding engine orders are cancelled, and it sounds clean and pretty distinctive. There is also some induction noise that mixes with exhaust to make the overall sound. That is tuned as well.

It would take a lot of work, and fabrication to make an F-body approach the sound of a Ferrari, and I don't think you'd ever really get there. Too many differences upstream of the tailpipe. You could make a very nice sound with equal-length headers and downpipes, an H or X pipe and the proper mufflers, tuned, not just some bullet resonators hanging there. Packaging is a nightmare though. You'd have to give up a lot of clearance on the left side (remember, equal length is important). You'd probably need to give up a few horses to get the right tuning as well if you wanted to make it sound great instead of just loud. Oh yeah, and rev it to 8500. :)

Another thought on the quarter-wave tuning (organ pipe) OldSS mentions. The frequency being attenuated is related to the diameter and length of the pipe. Larger diameters need longer tubes to be effective for a given frequency. Short tubes, small diameter= narrower frequency band. Larger diameter, longer tube=wider band attenuation at the same frequency. Too small=not effective. Same can be said for the tube in a Helmholtz tuner, but you now have the chamber volume that must change as well.

Enough typing... My $.02

Good post Nate.

I was telling OldSStroker "I wonder when Nate will chime in on this post?"

We have to get you two together with a few beers and design some exhaust systems, at least one for my 64 GTO and his Lakes Modified.

Bret

Originally posted by nateh
The OEM was Arvin. It was in the '60s. Put a closed pipe off the main exhaust pipe and tack it further down so it runs parallel. Arvin called it the Arvinode. It was a simple quarter-wave tuner. It's very effective at targeting a single frequency band. A Helmholtz tuner is a similar concept, with a volume combined with the tube. It widens the attenuation band and works better.
...
Another thought on the quarter-wave tuning (organ pipe) OldSS mentions. The frequency being attenuated is related to the diameter and length of the pipe. Larger diameters need longer tubes to be effective for a given frequency. Short tubes, small diameter= narrower frequency band. Larger diameter, longer tube=wider band attenuation at the same frequency. Too small=not effective. Same can be said for the tube in a Helmholtz tuner, but you now have the chamber volume that must change as well.

Enough typing... My $.02

Great post, Nate. Many good points that I didn't think of.

Maybe even before Arvin's work, or along with them, a Pontiac development engineer spent a lot of time on this project. It was '63-'65 if I recall. I wonder if any patents were ever issued. The engineer was Tom Cassel (spelling?). He'd be in his 70's now.

How critical would it be to tap into the main exhaust tube art a positive pressure node with the engine running at a particular rpm, say 65 mph cruise? That seemed to be important as I observed Tom's work. I was an engineering student then, and spent a lot of time observing and learning. FWIW, I was fortunate enough to work with/for some really sharp guys back then.


So how about an exhaust processor with a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes. Plug it into the PCM to control the sound. Think it would work? ;)


Thanks again, Nate.

Jon

Originally posted by Injuneer
Hey.... wait a minute! Shouldn't that be "...... poor grammar and spelling are tolerable...... "

:D :D

Somebody ought to try and control this thread...........

:lol:

Proof that I have no business correcting anyone.:)

Originally posted by nateh
Exhaust tuning is 1 part science and 1 part black art. The guys who are really good at it have been doing it for years. They can look at an engine and pipe configuration and give the OEM an 85% good solution on the first try from prototype. The money is in the remaining 15%. Computer simulations are lucky to get halfway there on the first try.

They should fire that team of programmers.;)

Programs can and have been extremely accurate in the most dizzying array of simulations. GIGO, gotta have sound mathematical models if you want to get there though....

Very interesting response!

The OEM guys have it tough though... they have to design an exhaust system that doesn't hamper performance too much, yet meets stringent noise control criteria. If I worked in that field, I'd be fired cause they'd all come off the block sounding like a 426 hemi..... rickity-tickity-rickity-tickity.:D

-Mindgame

Originally posted by OldSStroker
Great post, Nate. Many good points that I didn't think of.

Maybe even before Arvin's work, or along with them, a Pontiac development engineer spent a lot of time on this project. It was '63-'65 if I recall. I wonder if any patents were ever issued. The engineer was Tom Cassel (spelling?). He'd be in his 70's now.

How critical would it be to tap into the main exhaust tube art a positive pressure node with the engine running at a particular rpm, say 65 mph cruise? That seemed to be important as I observed Tom's work. I was an engineering student then, and spent a lot of time observing and learning. FWIW, I was fortunate enough to work with/for some really sharp guys back then.


So how about an exhaust processor with a Helmholtz resonance chamber with a variable tuning throat. The tuning frequency of the exhaust processor changes as the outlet opening from the variable tuning throat into the Helmholtz resonance chamber changes. Plug it into the PCM to control the sound. Think it would work? ;)



Thanks again, Nate.

Jon

Jon,
I'm sure there were patents issued, but I don't know to whom. The timeframe you mention is exactly when that activity was highest, so you're right on with the recollection. I did see mention of an ArviNode on a '64 Fairlane. I don't know for sure, but I don't think too many actually made it to production. Probably due to cost and durability issues.

Location of the silencing element is one of the most critical things to consider. It's also one of the most ignored in OEM circles because of packaging (you know spare tires, fuel tanks and such in the way). If you are targeting a specific frequency, you need to place the silencing element at the quarter-wave point of that frequency, or as close as possible. It can be measured from the engine or from the tailpipe, but a lot like to measure from the tailpipe and place the box with as much pipe behind it as possible. That's why tuning a mid-engine car is so difficult. There is little pipe length before or after the muffler, so getting the tuning elements placed properly is next to impossible. Given that the optimal never occurs and designers have to target noise in several areas, it's a testament to how well they get things to work. It's amazing to me sometimes that they get some of these things legal.

With the organ pipe, placement is critical. It could be completely ineffective if put in the wrong place.

If you know what RPM you want to target, you can get the fundamental frequency. From the freqency you can get the wavelength and you can place the pipe. If you have an unequal-length y-pipe though, the problem might not be at the fundamental firing frequency. It might be some odd order (like 1.5 times or 1.625 times firing frequency) and that would change the requirements. The 80's and 90's Pontiac V-6 blatty sound is an example. If you have equal-length downpipes and an h or x pipe, the frequencies you hear will be predominately fundamental firing. Think Mustang GT for example.

I think your PCM controlled system would work for a narrow range of conditions, but it would never make it past the pass-by test. The latency associated with changing the tube length would mean it wouldn't work for the first part of an abrupt throttle change. The pass-by test involves approaching a trap at a set speed (30 mi/hr or 50 km/hr, depending on the test) and going to WOT at a pre-determined point and going through the trap.

You're touching on the active noise cancellation that we talked about a few weeks ago in another thread. Doable, but very expensive and not too durable.

Interesting note: Many years ago, development people used to use a "kwinkie tube," that was a variable length tuning throat, exactly like you describe. They'd use it to quickly identify the problem frequency by tapping into the exhaust and changing the tube effective length until they got some cancellation. Then they'd tune the prototype muffler to hit that frequency. Nowadays, a frequency sweep with respect to RPM on a dyno roll lets you see immediately all the problems at any point in the RPM band.

Mindgame,
I know just how you feel on how it should work, and I agree. The problem is there is still not enough information on everything that contributes to and affects the noise. The big things are easy, but other stuff is difficult to quantify. How about quantifying the acoustic effects of an aluminum engine block vs. an iron block. Does it affect sound out the tailpipe? Pipe thickness, material? Hanger locations? Cam timing events (obviously, but quantify it)? Calibration and strategy in the ECM? Interactions between any of the above? It gets seriously complex. The software is admittedly better than it used to be, but it still has a hard time with a lot of configurations. There is also the aspect of time. It can take someone days to set up the whole simulation properly, with the system modeled in the computer. The development engineer can get prototypes very quickly if he has to. It's most often faster to order a batch of prototypes and test them than to try to model all the muffler internals separately and run simulations. Believe me, simulations do figure prominently in a lot of development, especially when you don't have a test vehicle or engine, but when it comes down to the end of development, the final parts are designed, prototyped and tested by a person. It happens often enough when the simulation suggests one thing and actual testing shows different. No one is giving up on computer simulations though. It's going to happen more and more. The models get more and more accurate every year.

Sorry to post so long.

Post as much as you want Nate... we'll read it.:)

WAVE is an extremely accurate simulation program that can do just what we're proposing. I don't work in the automotive field but I know of WAVE from my dealings with Chuck Riddeck last year. Maybe he'll chime in.

Here's the information from Ricardo's website.

CALCULATION OF THE TAIL-PIPE NOISE OF EXHAUST SYSTEMS WITH WAVE
Rolf Jebasinski, J. Eberspacher (Ricardo Software International User Conference, Detroit, March 1996)

In the past the calculation of exhaust systems tailpipe noise was a problem which was only unsatisfactorily solved. This paper shows the possibilities of engine simulation programs based on one- dimensional Computational Fluid Dynamics codes, such as WAVE, to calculate the tail-pipe noise of exhaust systems. Comparison of simulation and measurement show that it is possible to accurately predict tail-pipe noise if the muffler, with all interior piping systems, is correctly modelled. Even 3-dimensional effects can be simulated with a special modelling approach. In addition the backpressure can be calculated so that the whole exhaust system can be optimized with respect to tail-pipe noise and backpressure. With the new preprocessor KADOS for WAVE, which significantly reduces the time for modelling exhaust systems with WAVE, new potentials arise for the development and optimization of exhaust systems.

What amazes me these days is the amount of information out there. Here we are having a discussion on exhaust systems and how to create the sound you're after..... almost by accident I found this article on the new GTO. Fascinating... cause it goes right along with what everyone here has been saying about creating a "characteristic" sound. The engineers went through a bit of effort to do just that.

http://ultimategto.com/monaro13.htm

-Mindgame

Wave is the big player in the exhaust simulation field. It is well used. It's very cool, but the truth is that no one dares to take the results of a Wave simulation and make production tooling decisions based solely on them, especially late in the program, when tool changes are serious $$$$. You always test to see if there is a difference and there nearly always is one, even if it's a five percent variation in some areas. Then, you need to tweak the design using experience and trial and error to get it right. That's on a simulation that comes out really good. There are others where the real-world results aren't really close to agreement with the model, and a human could make a first shot much closer. It becomes a time thing, which is faster?

Wave is used in the industry to try to narrow the designs down in the absence of a vehicle. We do development without vehicles more and more early on in a program. It is very useful, but it isn't dead on and you always correlate the data. It is, as I said, getting better. It isn't cheap either. :)

Worked as a program director for a while. I can tell you about the cost of developing accurate software applications.:)

You're right Nate, the program is not going to give you a perfect model, but it does create a good starting point. There are always going to be a number of prototypes based off that original concept. The importance here is getting that "original concept".

The GTO team I referenced in my last response... same situation there.

The beauty of software goes much further than original design. You have a design team working on the project. An original concept is developed, that concept is used to create a computer model. That computer model is associative, in that any changes in say a chassis component will automatically update the exhaust design should it fall out of certain constraints. From original design, you have an accurate model for the simulation. That model is used for simulation and it is used for manufacturing. Speeds the entire process.

I guess the point I'm trying to make here is, it goes further than getting that first design. Nothing cheap about it when you look at initial expenditures, but the return on investment can be substantial for a company that does this continually.

-Mindgame

Yup, that's how it's supposed to work, and sometimes it does. What do they say about it works that way in theory, but not always in practice? There's a catchy saying there somewhere that I can't remember. Jon probably could...

I need to comment that several of you demonstrate remarkable understanding in a wide variety of areas. Jon, Mindgame, you guys seem to know a lot about a lot, even though the topic may not be in your primary area of expertise. You, and several others, specifically Bret, Ken, Fred, and more make it a pleasure to browse the forums. Thanks...

Originally posted by nateh


I need to comment that several of you demonstrate remarkable understanding in a wide variety of areas. Jon, Mindgame, you guys seem to know a lot about a lot, even though the topic may not be in your primary area of expertise. You, and several others, specifically Bret, Ken, Fred, and more make it a pleasure to browse the forums. Thanks...


Advanced Age helps a lot. Old Farts like me have just experienced more, read more, talked more(!) than you young guys. Some of it is retained. Keeping the mind active seems to help retain more of the stuff that has been accumulated over the decades.

BTW, I don't have a primary area of interest. That's too boring. :)

Thanks, Nate.

Originally posted by nateh
Yup, that's how it's supposed to work, and sometimes it does. What do they say about it works that way in theory, but not always in practice? There's a catchy saying there somewhere that I can't remember. Jon probably could...

The difference between theory and practice in theory is much less than the difference between theory and practice in practice

That the one you're looking for? :)

I need to comment that several of you demonstrate remarkable understanding in a wide variety of areas. Jon, Mindgame, you guys seem to know a lot about a lot, even though the topic may not be in your primary area of expertise. You, and several others, specifically Bret, Ken, Fred, and more make it a pleasure to browse the forums. Thanks...

Not as old and wise as some around here but extremely eclectic. To myself and probably alot of other gentlemen here... living is all about learning.

Now if I could just motivate my nephew....

-Mindgame

WOW :eek: :bow:
I know this were the place to ask for.
I love the corsa sound, this C5 sound are just what I looking for my Z but they don´t sound even close in the C5 to the LT1 :confused: or LS1 Z.

C5 http://www.corsaperf.com/flashc5.htm

LT1 http://www.corsaperf.com/flashcam-fire.htm

LS1 http://www.corsaperf.com/gm/cfflash.htm

This kind of makes me wonder about those tuning for power and sound. Do guys just add spacers to the headers in small incrememnts? What size are these increments (its gotta be based on wavelenth but I don't know it).
Also, this reminds me of the polarizing experiments i did in an old physics class and the comments of a chemistry teacher.
Has anyone ever tried using a grating with very small slits in only one direction? It'd be very restrictive so you'd have to make the diameter of the tube alot bigger at that point.
It'd let through only one plane of waves, and you could have another grating set up further down that you could adjust by turning it.

edit: also, to expand on his question, what is it that made the old trans-am series cars sound so real?

WOW :eek: :bow:
I know this were the place to ask for.
I love the corsa sound, this C5 sound are just what I looking for my Z but they don´t sound even close in the C5 to the LT1 :confused: or LS1 Z.

C5 http://www.corsaperf.com/flashc5.htm

LT1 http://www.corsaperf.com/flashcam-fire.htm

LS1 http://www.corsaperf.com/gm/cfflash.htm


Yeah, the c5 corsa does sound pretty amazing, i have to wonder if the differance is in the exhaust itself or the engines, the ls1 and c5 have simular engines if not the same so u would thing they would sound simular???

That's an extremely high revving (7200+ rpm) LS1 in the C5 soundfile. I wonder if they "enhanced" it. :lol:

Here's what a 6800 rpm shift sounds like:

http://kraest.com/vette/2ndgear.mov