Reverse-cone megaphones for V-11 Sport?

[GuzziMoto]

The exit hole is exactly the same diameter as the inlet on this pipe and I 've have had it apart.

 

That is why it is not as loud

 

 

Can u post a diagram of your "true" reverse cone meg as the twenty or so pictures I've just looked at of race bike reverse cones all have an outlet the same or slightly larger than the inlet and I still see fail to see how u can fit a baffle after the reverse cone when said cone is at the end, why would u fit a RC inside the exhaust and the a baffle after to quieten it,its like putting the horse before the cart

 

The reverse cone is only at the end if you don't want to quiet down the noise. Once upon a time people didn't care about how loud it was, only how fast it went. RCMs did not have mufflers tacked on to the end of them. Life was good (but loud). Then they started passing and enforcing all kinds of noise regulations, first on the street (which relegated most RCMs to track use) then on race tracks (which probably lead to the development of the RCM muffler. Now, it is true that some mufflers that look like reverse cone megaphones are in fact just mufflers with an outside shape to look like the real thing. But there are a few companies that still to this day build true RCM mufflers (and RCMs with out mufflers). In general the size of the outlet in relation to the size of the inlet gives you an idea of how noisy and how much power an RCM will make. The outlet should be atleast 30 -50% larger then the inlet but you will find everything from the same size to twice as big. It isn't so much about right and wrong but about what the intended use is. Unfortuneatly in this case max power equates to max noise.

Cobra and Ron Woods are probably two of the biggest makers of RCM mufflers I know of. Unfortunately both have moved away from making RCM exhausts for bikes and focused on ATVs (presumably there is more money there).

 

Here are some links. The first one is a crappy site but the pictures show three different RCM's with mufflers on the end.

http://www.thefind.com/sports/browse-cobra-megaphone

 

This one is a Guzzi racebike with an unmuffled RCM giving you an idea what I mean about the size of the outlet.

Click on the top two pics to enlarge.

http://www.s3750motoguzzi.co.uk/david-v7sp...vidV7racer.html

 

And this is a RCM with muffler made by Ron Woods for BMW/Rotax singles.

http://www.rotax.net/pics/bmwexhaustbig.jpg

 

Finally, here is a link to some RCM exhausts with mufflers made by Ron Woods for ATVs.

http://www.rotax.net/ds450.html

 

I hope this helps.

[gavo]

The reverse cone is only at the end if you don't want to quiet down the noise. Once upon a time people didn't care about how loud it was, only how fast it went. RCMs did not have mufflers tacked on to the end of them. Life was good (but loud). Then they started passing and enforcing all kinds of noise regulations, first on the street (which relegated most RCMs to track use) then on race tracks (which probably lead to the development of the RCM muffler. Now, it is true that some mufflers that look like reverse cone megaphones are in fact just mufflers with an outside shape to look like the real thing. But there are a few companies that still to this day build true RCM mufflers (and RCMs with out mufflers). In general the size of the outlet in relation to the size of the inlet gives you an idea of how noisy and how much power an RCM will make. The outlet should be atleast 30 -50% larger then the inlet but you will find everything from the same size to twice as big. It isn't so much about right and wrong but about what the intended use is. Unfortuneatly in this case max power equates to max noise.

Cobra and Ron Woods are probably two of the biggest makers of RCM mufflers I know of. Unfortunately both have moved away from making RCM exhausts for bikes and focused on ATVs (presumably there is more money there).

 

Here are some links. The first one is a crappy site but the pictures show three different RCM's with mufflers on the end.

http://www.thefind.com/sports/browse-cobra-megaphone

 

This one is a Guzzi racebike with an unmuffled RCM giving you an idea what I mean about the size of the outlet.

Click on the top two pics to enlarge.

http://www.s3750motoguzzi.co.uk/david-v7sp...vidV7racer.html

 

And this is a RCM with muffler made by Ron Woods for BMW/Rotax singles.

http://www.rotax.net/pics/bmwexhaustbig.jpg

 

Finally, here is a link to some RCM exhausts with mufflers made by Ron Woods for ATVs.

http://www.rotax.net/ds450.html

 

I hope this helps.

 

Those cobra pipes are plain ugly and although you can't see inside the muffler the rotax pipe it is a very loose interpretation of a rcm try these

http://www.giannelli.com/eng/prodotti/lin.asp?id=143

http://www.staintune.com.au/exhausts/ducat...00_DU_MS_GT.htm

http://www.staintune.com.au/exhausts/trium...everse_Cone.htm

http://ijms.nova.edu/March2005/Ward0305j.jpg

http://www.vikingexhaust.com/utils/uploads.../SIL-2015-2.jpg

these are a true/ traditional rcm with the gianelli more modern.

straight megaphones may give the most power and noise but this does't always make the fastest bike

[belfastguzzi]

Thanks very much folks: great material. I have a much better grasp of it now.

 

I found some other pics and a reference to these books, which you probably know about: "books written by john bradley who takes you from a to z in one off motorcycle construction. these books are facinating, well written, easy to read." ?

[GuzziMoto]

Those cobra pipes are plain ugly and although you can't see inside the muffler the rotax pipe it is a very loose interpretation of a rcm try these

http://www.giannelli.com/eng/prodotti/lin.asp?id=143

http://www.staintune.com.au/exhausts/ducat...00_DU_MS_GT.htm

http://www.staintune.com.au/exhausts/trium...everse_Cone.htm

http://ijms.nova.edu/March2005/Ward0305j.jpg

http://www.vikingexhaust.com/utils/uploads.../SIL-2015-2.jpg

these are a true/ traditional rcm with the gianelli more modern.

straight megaphones may give the most power and noise but this does't always make the fastest bike

 

The Giannelli appears to be what I was refering to as a muffler that mimicks the look of a RCM but is in fact NOT a RCM. In order for it to be a "true" RCM the interior volume of the RCM must not have baffles or anything else that would interfer with flow. That is why "true" RCM mufflers put the baffle AFTER the RCM. The Staintunes are probably the same but the links did not open for me. I am not refering to a "true" RCM based on what it looks like but on how it works. You may not like the look of an RCM with a muffler on the end but that has nothing to do with what it is or how it works. The Woods pipes and Cobra pipes are "true" RCMs with mufflers on the ends, the Giannelli (and almost certainly the Staintunes) are not. But I would agree they look better.

The Viking pipe is either a true RCM with no baffle or a muffler mimicking the look of an RCM but not the performance. Without being able to see if there is a baffle inside I can not tell. Whichever it is, it is NOT a RCM with a muffler. It is either a RCM OR a muffler (just like the Giannelli and Staintune).

 

 

Edir: FYI... I ended up yanking my GuzziTech pipe from Todd apart to confirm that yes indeed it is a "true" reverse cone megaphone design. The pipe diameter gets progressivly larger then tapers back down some and then the baffle/muffler is on the outlet of the reverse cone. The reverse cone on the end is for looks. The cone that makes it a "true" RCM is inside the pipe and cannot be seen from the outside.

[gavo]

The Giannelli appears to be what I was refering to as a muffler that mimicks the look of a RCM but is in fact NOT a RCM. In order for it to be a "true" RCM the interior volume of the RCM must not have baffles or anything else that would interfer with flow. That is why "true" RCM mufflers put the baffle AFTER the RCM. The Staintunes are probably the same but the links did not open for me. I am not refering to a "true" RCM based on what it looks like but on how it works. You may not like the look of an RCM with a muffler on the end but that has nothing to do with what it is or how it works. The Woods pipes and Cobra pipes are "true" RCMs with mufflers on the ends, the Giannelli (and almost certainly the Staintunes) are not. But I would agree they look better.

The Viking pipe is either a true RCM with no baffle or a muffler mimicking the look of an RCM but not the performance. Without being able to see if there is a baffle inside I can not tell. Whichever it is, it is NOT a RCM with a muffler. It is either a RCM OR a muffler (just like the Giannelli and Staintune).

 

 

Edir: FYI... I ended up yanking my GuzziTech pipe from Todd apart to confirm that yes indeed it is a "true" reverse cone megaphone design. The pipe diameter gets progressivly larger then tapers back down some and then the baffle/muffler is on the outlet of the reverse cone. The reverse cone on the end is for looks. The cone that makes it a "true" RCM is inside the pipe and cannot be seen from the outside.

 

Now thats interesting that means the muffler picture I posted of my ducati has a simple perforated tube as the baffle, nothing else unless I decide to rap it to make it quieter, however I can remove that in a matter of minutes then it would be a megaphone with a reverse cone on the end. I still fail to see how placing the baffle inside would suddenly make it an untrue rcm(I'm not trying to be a smart ass I'm just trying to understand your logic)after all this reverse cone on the end is all there is.

[Skeeve]

Now thats interesting that means the muffler picture I posted of my ducati has a simple perforated tube as the baffle, nothing else unless I decide to rap it to make it quieter, however I can remove that in a matter of minutes then it would be a megaphone with a reverse cone on the end. I still fail to see how placing the baffle inside would suddenly make it an untrue rcm(I'm not trying to be a smart ass I'm just trying to understand your logic)after all this reverse cone on the end is all there is.

 

Here's a way to get your head around it:

 

If you stick a sock up the end of a clarinet, is it still a clarinet? OK, maybe, but it won't play like one. Now, if build the f@cking sock into the clarinet it's not a clarinet anymore, is it?

 

An RCM is all about acoustics. Stick a sock in it [or baffle, what have you], and you've ruined the acoustics & it's no longer an RCM, it's a muffler. Got it?

[gavo]

Here's a way to get your head around it:

 

If you stick a sock up the end of a clarinet, is it still a clarinet? OK, maybe, but it won't play like one. Now, if build the f@cking sock into the clarinet it's not a clarinet anymore, is it?

 

An RCM is all about acoustics. Stick a sock in it [or baffle, what have you], and you've ruined the acoustics & it's no longer an RCM, it's a muffler. Got it?

 

Yes its still a clarinet with a built in sock but really I think this has become a class half full kind of discussion. I know the lenght ,diameter and taper are all governed by the tuning characteristics your after so why can't an internal baffle be taken into account in the design parameters. and incidently my baffle seems to make very little differance so I'm gonna have to agree to disagree

[GuzziMoto]

Yes its still a clarinet with a built in sock but really I think this has become a class half full kind of discussion. I know the lenght ,diameter and taper are all governed by the tuning characteristics your after so why can't an internal baffle be taken into account in the design parameters. and incidently my baffle seems to make very little differance so I'm gonna have to agree to disagree

 

It is only going to LOOK like a clarinet, it isn't going to WORK like a clarinet. If you only care about the look, then having a "true" RCM is not important. But when someone like Todd refers to selling a "true" RCM he is refering to one that actually does what a RCM does.

[raz]

Just call them Reverse Cone Megaphones versus Reverse Cone Mufflers and everybody's happy. Or not? Maybe this is the new Oil Temp Sensor thread

[gavo]

It is only going to LOOK like a clarinet, it isn't going to WORK like a clarinet. If you only care about the look, then having a "true" RCM is not important. But when someone like Todd refers to selling a "true" RCM he is refering to one that actually does what a RCM does.

 

Or like stretching the sock over the end ofyour clarinet it would still work but would detract from peak performance

Also it wouldn't have a muffler on the end it would just be a race pipe not suitable for the street.

its funny how most exhaust manufacturers on the web still refer to their products as of that style as rcm's baffled or not but what would they know they only design and make them. therefore a true (for want of a better term) rcm wouldn't have a baffle anywhere cause then itwould be sumpin else