[oldbogie]

Originally Posted by DanielC

I still think there is something to the 180 crankshaft in a Ferarri. It alternates cylinder banks firing evenly.
A 90 degree V-8 engine with a 90 degree crankshaft fires banks in this order, (Ford) Right, left, right, right, left, right, left, left., or right, right, left, right, left, left, right, left.

I am a little familiar with a Helmholtz resonator. I built two Subwoofers for live sound, that are ported 14 cubic foot boxes, with two Electro-voice DL-18-W speakers in them. These boxes have a flat frequency response down to 34 Hertz, and drop off as 12 DB, per octave below that. I run the crossover frequency about 150 HZ.

The angle between cylinder banks and the angle between the throws of the crank establish the cadence this is why a Harley sounds like a Harley, why Yamaha and Triumph use a 270 degree angle between throws on some models using an inline configuration to get the Harley beat that otherwise comes from a 45 degree V-twin. And yes one can conclude that a 270 degree crank in a parallel twin doesn't improve their power output. When Honda decided to pursue the Harley sound with their cruisers many years ago, they took the 45 degree between cylinders V-twin they built with 45 degrees between crank throws so it ran and sounded like a 90 degree V-twin (Ducati?). They put in a single throw crank and twisted the cam lobes around for that crank timing but didn't change the lobe configurations or compression ratio. 5 horespower dissappeared into the vibration that is an integral part of a 45 degree V-twin configuration which is caused by the odd time beat of cylinder firing imposed by that configuration.

Beyond the beat the cam and compression set a level of aggression to the tone quality, where high compression and big cams tend to pound a sharpness or crispness into the sound. You can tune in or out the notes (sound frequency) you want to hear with pipe lengths, mufflers, resonators and the like. Frankly, I don't build engines for their sound, except for my Harley.

Bogie

[vinniekq2]

oldbogie,didnt Harley patent the harley sound so honda and others could not copy them?

[DanielC]

On a ported speaker box, the free air resonant frequency of the speaker influences the tuning of the system, the speaker mounted in the box. You tune the system, using a variable frequency generator, with a sine wave. As you go down to the resonant frequency of the system, the speaker cone itself actually moves less, and less, until at the tuned frequency of the box and speaker the speaker cone is not moving much at all, as the acoustic energy is coming out of the ports. Go below that frequency, however, and the speaker cone excursion (travel) rapidly increases, and it gets very easy to "bottom out" the speaker cone.
Here is a picture of one side of my sound system set up in a gym, for a dance competition.


While on the subject of exhaust sound, consider this thought. If you hand a trumpet played by Miles Davis, to a 13 year old member of a high school band, the band member is not going to sound like Miles Davis playing a trumpet.

There, that is a better post number.

[vinniekq2]

so Daniel,is this like comparing a first priority crossover and a fourth priority cross over, and comparing them to an "X" pipe Vs an "H: pipe?

Then I guess a pizo tweeter is like mild steel tubes compared to a ribbon tweeter being like stainless tubes,,,sound wise?

[hcompton]

Originally Posted by vinniekq2

oldbogie,didnt Harley patent the harley sound so honda and others could not copy them?

Why not put the x pipe where you can cut the piping back until you have the sound you need? Just clamp it in until it sounds right then weld her up.

Harley uses a single crank pin with inner and out connecting rods. So both pistons come around at the same time. And you bet your butt its pattented. Honda would love to have that design. The unique harley sound comes from the heavy crank shaft and pin location with the 45 degrees cylinders. Harly v twins are inline all other are offset for the rod palcement. If you have never seen one its a cool read. More amazing they are bolted together. I bet they are heavier than a chevy v8 crank. Most hondas use 32 degree for less vibration.

Uh then borla? This sounds very ferrarish. The long gearing of the race car makes the exhuast sound alot better as the one shot shows it pulling away. Right about 1 min in they have the sound of all 3 exhuast each sounds different and a little european. And yes i know thats not a gen one motor.

BORLA Exhaust for the C6 Corvette - YouTube

BORLA Exhaust for the C6 Corvette - YouTube

[John long]

Originally Posted by vinniekq2

oldbogie,didnt Harley patent the harley sound so honda and others could not copy them?

They did apply for the patent but my understanding is it was denied.

John L

[blight]

Originally Posted by hcompton

Why not put the x pipe where you can cut the piping back until you have the sound you need? Just clamp it in until it sounds right then weld her up.

Harley uses a single crank pin with inner and out connecting rods. So both pistons come around at the same time. And you bet your butt its pattented. Honda would love to have that design. The unique harley sound comes from the heavy crank shaft and pin location with the 45 degrees cylinders. Harly v twins are inline all other are offset for the rod palcement. If you have never seen one its a cool read. More amazing they are bolted together. I bet they are heavier than a chevy v8 crank. Most hondas use 32 degree for less vibration.

Uh then borla? This sounds very ferrarish. The long gearing of the race car makes the exhuast sound alot better as the one shot shows it pulling away. Right about 1 min in they have the sound of all 3 exhuast each sounds different and a little european. And yes i know thats not a gen one motor.

BORLA Exhaust for the C6 Corvette - YouTube

That vette has factory tri-y and a an x pipe farther back just like a maserati v8 and alfa and s65 bmw... that is what you are hearing. the tri-y on the facotry vette still isn't quite right. The tubing is not in the perfect position to get the best result out of the engine. This is talking ls series.

also less vibration is a better design. engine harmonics come into play for that .02 hp that you are looking to have over the other guy. They can be much more than that depending on design to design.

Harley tried patenting the sound, there was a big lawsuit with them and yamaha. It got thrown out of court because it was silly- more or less.

[blight]

Originally Posted by John long

They did apply for the patent but my understanding is it was denied.

John L

Yes sir you are correct. For many reasons it was.

[blight]

Originally Posted by oldbogie

The angle between cylinder banks and the angle between the throws of the crank establish the cadence this is why a Harley sounds like a Harley, why Yamaha and Triumph use a 270 degree angle between throws on some models using an inline configuration to get the Harley beat that otherwise comes from a 45 degree V-twin. And yes one can conclude that a 270 degree crank in a parallel twin doesn't improve their power output. When Honda decided to pursue the Harley sound with their cruisers many years ago, they took the 45 degree between cylinders V-twin they built with 45 degrees between crank throws so it ran and sounded like a 90 degree V-twin (Ducati?). They put in a single throw crank and twisted the cam lobes around for that crank timing but didn't change the lobe configurations or compression ratio. 5 horespower dissappeared into the vibration that is an integral part of a 45 degree V-twin configuration which is caused by the odd time beat of cylinder firing imposed by that configuration.

Beyond the beat the cam and compression set a level of aggression to the tone quality, where high compression and big cams tend to pound a sharpness or crispness into the sound. You can tune in or out the notes (sound frequency) you want to hear with pipe lengths, mufflers, resonators and the like.


Frankly, I don't build engines for their sound, except for my Harley.

Bogie

I agree with you. This particular build is my baby. I care about every minute detail. Taking it as far as the quality of the magnesium lug-nuts. I called the manufacture for the heat number on the material they were using to see exactly what temp they went through. I am that anal about this one. There will be very few cars that will be able to compete with this thing when said and done. I figured as long as I am required to design an exhaust system i would aim for a combination of power and sound aesthetism (new word just now...). Interesting enough the design that makes more power (stepped, equal length primaries, tri-y or 180 degree headers to an x pipe and side exit mufflers) sounds the best to my ears. To the rest of ya- tis my car so its my ears that matter. On a side note- I have been playing a number of instruments for about 21 years. I have been writing music for 18 years. I play by ear. I wonder if that makes any difference to my preferences in engine sound.

[blight]

Originally Posted by vinniekq2

so Daniel,is this like comparing a first priority crossover and a fourth priority cross over, and comparing them to an "X" pipe Vs an "H: pipe?

Then I guess a pizo tweeter is like mild steel tubes compared to a ribbon tweeter being like stainless tubes,,,sound wise?

The material will vibrate differently changing the speed of sound which will change the frequency produced. Stainless -period, is the way to go. Frequency travels significantly faster via metal than air.

[hcompton]

Originally Posted by blight

That vette has factory tri-y and a an x pipe farther back just like a maserati v8 and alfa and s65 bmw... that is what you are hearing. the tri-y on the facotry vette still isn't quite right. The tubing is not in the perfect position to get the best result out of the engine. This is talking ls series.

also less vibration is a better design. engine harmonics come into play for that .02 hp that you are looking to have over the other guy. They can be much more than that depending on design to design.

Harley tried patenting the sound, there was a big lawsuit with them and yamaha. It got thrown out of court because it was silly- more or less.

Yes but i grabbed the c6 video cause you need an engine with high rpm redline, high compression and long gears. Most american cars are geared short when compared to euro toys. They make a system that give the same sound to the c4 as well. But c4 is short gear long stroke and lower compression so you dont get as close to what your looking for.

Borla has been building exhuast with the euro sounds for american cars for many years. It was there claim to fame back in the day.

Hear is what i am saying alot of the sound comes from the muffler. All ferrari sound good right even ones from the 60's before they had x pipes and tri Y they still had the ferrari sound. Most of the rear engine ferraris i have crawled under had dual in and out but single muffler.

If you remove the mufflers from a ferrari they sound as bad as any car uncapped. They sound loud and flat. Now the newer cars with cats and more complex exhuast still hold some of the sound as they have a lot of restrictions in the exhuast. I have removed the exhuast from a few of them and was sure to start the car with the pipes off. Just blah shift blahhhhh. Same as any car without the pipes. Putting quiet mufflers is also bad. You could not belief how much noise there engines make. Loud exhuast actually hides a very ticky tappy engine.

The reason i was asking question is if you calculate x pipe location it usally falls under the trans and does not fit there. For most cars you end up needing to put it where it fits not where its perfect for performance. Your really looking for a musical note in the right octave. You probably want to tune the x pipe for that note not the mathmaticaly perfect location for performance. Ferrari are not tuned for total performance they are tuned to make rich guys happy. Also a high rpm v6 may sound closer to a v12 than a v8. Just trying to help.

[DanielC]

"On a side note- I have been playing a number of instruments for about 21 years. I have been writing music for 18 years. I play by ear. I wonder if that makes any difference to my preferences in engine sound. "

Of course it does. You know that a trumpet, a coronet, and a flugelhorn all sound different, even though they all play the same notes.

[oldbogie]

Originally Posted by DanielC

"On a side note- I have been playing a number of instruments for about 21 years. I have been writing music for 18 years. I play by ear. I wonder if that makes any difference to my preferences in engine sound. "

Of course it does. You know that a trumpet, a coronet, and a flugelhorn all sound different, even though they all play the same notes.

Sitting in front of speakers like those in your picture, flying helicopters and airplanes, riding Harleys, shooting guns, working in the shop, building and operating hot rods, drag racers, etc. for 60 years without bothering about noise protection is why I wear hearing aids in both ears, especially the right (Harley exhaust) side ear is more dead than not, but it didn't go quietly it screams with high pitched ringing all the time.

Bogie

[ap72]

Originally Posted by hcompton

Yes but i grabbed the c6 video cause you need an engine with high rpm redline, high compression and long gears. Most american cars are geared short when compared to euro toys. They make a system that give the same sound to the c4 as well. But c4 is short gear long stroke and lower compression so you dont get as close to what your looking for.

Borla has been building exhuast with the euro sounds for american cars for many years. It was there claim to fame back in the day.

Hear is what i am saying alot of the sound comes from the muffler. All ferrari sound good right even ones from the 60's before they had x pipes and tri Y they still had the ferrari sound. Most of the rear engine ferraris i have crawled under had dual in and out but single muffler.

If you remove the mufflers from a ferrari they sound as bad as any car uncapped. They sound loud and flat. Now the newer cars with cats and more complex exhuast still hold some of the sound as they have a lot of restrictions in the exhuast. I have removed the exhuast from a few of them and was sure to start the car with the pipes off. Just blah shift blahhhhh. Same as any car without the pipes. Putting quiet mufflers is also bad. You could not belief how much noise there engines make. Loud exhuast actually hides a very ticky tappy engine.

The reason i was asking question is if you calculate x pipe location it usally falls under the trans and does not fit there. For most cars you end up needing to put it where it fits not where its perfect for performance. Your really looking for a musical note in the right octave. You probably want to tune the x pipe for that note not the mathmaticaly perfect location for performance. Ferrari are not tuned for total performance they are tuned to make rich guys happy. Also a high rpm v6 may sound closer to a v12 than a v8. Just trying to help.

And how exactly do you calculate the right length for the X-pipe?

[cobalt327]

Originally Posted by blight

I care about x pipe location.

Originally Posted by blight

I care about x pipe location.

Most times, the location of the crossmembers, transmission and etc. play a big part in where the crossover connector can be put.

The usual place is where the collectors would end if it was an open exhaust. If this is purely a sound thing, I doubt there will be any formula for computing where to locate it. Trial and retrial would be the best recourse IMO.