So was wondering about this the other day....
Most Ducatis with aftermarket exhasust give sort of a 'BOOM-BOOM-BOOM' sound, especially the larger carbon mufflers. I think some of the smller mufflers like MIVVs are a little more raspy. Also, the Hedman exhaust tips were reported to be kind of Harly like too.
Most Harley's with aftermarket exhaust give more of a 'BLAT-BLAT-BLAT' sharp note, and crack like hell when you open them up.
What gives here? Both are big twins, I would think you could make them sound similar if you wanted to. Is it just the different mufflers designs used or is there something more to it? Valve timing, cam profile, exhaust length, etc.
Just kinda wondering.
Thanks,
Scott
I think what you're hearing is the difference in the number of degrees of rotation between firings.
A Duc is 2700. A Harley is 3150. http://www.freerepublic.com/focus/f-chat/1464309/posts (http://www.freerepublic.com/focus/f-chat/1464309/posts)
The noise can be modified, but the firing pulses can't.
Freeper rider? Cool! [beer]
Quote from: ducpainter on February 19, 2010, 03:06:58 PM
I think what you're hearing is the difference in the number of degrees of rotation between firings.
+1, but my bike at idle with no cans sounds blatty like a harley ;D
Quote from: teddy037.2 on February 19, 2010, 04:55:04 PM
+1, but my bike at idle with no cans sounds blatty like a harley ;D
DP, I know that's why a Harley at idle gets that patented 'potato-potato' sound. That's the diff in degrees. No, what I'm talking about is what Teddy says. You can get a Duc to sound like a Harley but almost no one seems to want to ;) But I've never heard a Harley sound like a Duc.
Scott
Quote from: scott_araujo on February 20, 2010, 05:37:29 AM
DP, I know that's why a Harley at idle gets that patented 'potato-potato' sound. That's the diff in degrees. No, what I'm talking about is what Teddy says. You can get a Duc to sound like a Harley but almost no one seems to want to ;) But I've never heard a Harley sound like a Duc.
Scott
...because almost no one seems to want to? ;D
Dunno...I bet with a real exhaust you could get that basso profundo sound.
throw a pair of these on your bike in place of the oem exhaust system and your ducati will sound like a harley.
http://www.motocreations.com/exhausts.asp (http://www.motocreations.com/exhausts.asp)
Like this:
Flight cycles custom Ducatis (http://www.youtube.com/watch?v=Wd_YEo3nl0M#normal)
crank timing......
they , HD, are on the verge of taking a deep breath and running backwards.....
my xr750 , back in the day, after being bump started did this, deep breath chug backwards...
Quote from: scott_araujo on February 20, 2010, 05:37:29 AM
DP, I know that's why a Harley at idle gets that patented 'potato-potato' sound. That's the diff in degrees. No, what I'm talking about is what Teddy says. You can get a Duc to sound like a Harley but almost no one seems to want to ;) But I've never heard a Harley sound like a Duc.
Scott
personally, I'd rather it sound the way it does with the exhaust attached. don't know the science/magic/voodoo behind what makes short pipes and no muffler sound that way
but it was HI-larious firing that thing up in the garage halfway through the install... we all had a big laugh [evil] I was tempted to take a spin 'round the block and suprise all the neighbors
No voodoo just no packing to drown out some of the sound.
Quote from: uclabiker06 on February 20, 2010, 05:47:04 AM
Btw, that second chopper is a Ducati.
I think we're all pretty familiar with stew's bobber.
(http://www.flightcycles.com/FlightCycles/CoupDetat/Originals/DSC04021.jpg)
Quote from: uclabiker06 on February 20, 2010, 06:39:19 AM
No voodoo just no packing to drown out some of the sound.
I know that ;) but it just seems like size/shape/material of the can also seems to affect sound, and then there's size/length of the piping and all that other exhaust related stuff
[cheeky] [cheeky] [cheeky] [cheeky] [cheeky]
(http://www.pdq1.co.uk/TERMI_HD.jpg)
:o :o :o :o :o :o
sweeeet
A Ducati that sounds like a harley is running badly , A Harley that sound like a ducati is a really very hotted up bike ...........yes it can be done I did a 1200 sporster Flatracker years ago ,400lbs stage 4 engine ,dyno at 95bhp on reverse cone supertrapp system is sounded evil and went like stink but the investment was $10,000 just for tuning cosmetics and handling cost another $10,000
Quote from: DarkStaR on February 20, 2010, 02:09:04 PM
[cheeky] [cheeky] [cheeky] [cheeky] [cheeky]
(http://www.pdq1.co.uk/TERMI_HD.jpg)
I love sportsters but thats a really UGLY BIKE
Quote from: scott_araujo on February 20, 2010, 05:37:29 AM
DP, I know that's why a Harley at idle gets that patented 'potato-potato' sound. That's the diff in degrees. No, what I'm talking about is what Teddy says. You can get a Duc to sound like a Harley but almost no one seems to want to ;) But I've never heard a Harley sound like a Duc.
Scott
Maybe it should be pointed out that the newer "Twin Cam" big twins don't have the traditional "potato-potato-potato" cadence of the earlier big twins. This is because they idle higher (around 1100 rpm I think). The earlier big twins, including the Evos I think, idle around 700-800 rpm. An old H-D big twin idling at 700 sounds very different from anything else because of both the degrees of firing and idle rpm.
A few years ago I was at Lake Holbrook in Wood County, Texas. Some guy on an old Knucklehead came through the otherwise empty parking lot. He told me he had just resorted the thing, and indeed it look like it just rolled off the showroom floor. Those bikes had a manual advance timing actuated by a twist grip on the left side of the handlebars. It was rather cool to see him pull up, put it in neutral (with the tank shift), and then to hear the fast idle settle into the "potato-potato" as he twisted the grip and retarded the timing.
Granted, from the perspective of today's technology the thing was a dinosaur, but it was cool nonetheless.
I heard that the Japanese were making a clone of a '47 Knuckle Head, but with updated materials & technology. I think that would be a pretty cool ride. Granted, not a "motorcycle", but more akin to comparing a Model-T Ford to a ZO6.
Regarding sound, You have to keep in mind that most Harleys & their chopper clones are running in such a poor state of tune, it's ridiculous!
If you look at the pipes on almost any Harley other than a stocker, they are usually magenta & purple. Thank God my Duc doesn't sound like that!
Quote from: jerryz on February 21, 2010, 12:27:28 AM
A Harley that sound like a ducati is a really very hotted up bike ...........yes it can be done <snip>
+1
I've got a friend who rides a FatBoy with (amongst other things) a two into one Leo Vince exhaust that'd look perfectly in place on a Japanese sportsbike. It sounds a _lot_ like a Ducati...
big
I'd like to hear that sportster with termi carbon pipes. I almost bought one of those in 1963 when they were the fastest thing on the street in the U.S. They were one second faster in the quarter mile than my '64 Diana Mark 3 250 cc. Harley 883 - 13.5
Ducati 250 - 14.65 [laugh]
Then along came the Kawasaki 500 two stroke triple. 12.60 @ 108 mph
Quote from: 64duc on February 22, 2010, 02:08:30 PM
I'd like to hear that sportster with termi carbon pipes. I almost bought one of those in 1963 when they were the fastest thing on the street in the U.S. They were one second faster in the quarter mile than my '64 Diana Mark 3 250 cc. Harley 883 - 13.5
Ducati 250 - 14.65 [laugh]
Still have the Diana? ;D
Matter of fact I do. Or at least some of it.
nice [thumbsup]