Agostini Silencer Kit

[Joe]

Has anyone ever used Agostini Silencer Kit like this one? ....

[Lucky Phil]

Yes

Phil

[docc]

5 hours ago, Joe said:

Has anyone ever used Agostini Silencer Kit like this one? ....

Those would look (and sound!) sweeeet on a Rosso Mandello!

[Joe]

I currently have Mistral exhausts with crossover X pipe. Agostini says you must run a catalytic converter, where would I source one? Has anyone ran into this issue?

 

 
- no clamp gasket necessary !
- the catalytic converter 300001236 must only be used from 2003 V11 models, as these also had a catalytic converter as standard! (1 catalytic converter per rear silencer!)

[Joe]

Just ran into this on the internet.

 

https://picclick.com/Moto-Guzzi-V11-Sport-KR-Bj-2000-384510148867.html

[docc]

1 hour ago, Joe said:

I currently have Mistral exhausts with crossover X pipe. Agostini says you must run a catalytic converter, where would I source one? Has anyone ran into this issue?

 

 
- no clamp gasket necessary !
- the catalytic converter 300001236 must only be used from 2003 V11 models, as these also had a catalytic converter as standard! (1 catalytic converter per rear silencer!)

Pretty sure your US spec V11 didn't come with catalytic converters, this would be a non issue.

[Lucky Phil]

9 hours ago, Joe said:

I currently have Mistral exhausts with crossover X pipe. Agostini says you must run a catalytic converter, where would I source one? Has anyone ran into this issue?

 

 
- no clamp gasket necessary !
- the catalytic converter 300001236 must only be used from 2003 V11 models, as these also had a catalytic converter as standard! (1 catalytic converter per rear silencer!)

Buy a set for a 2000 V11 Sport. I'm not aware of any issues with muffler cross fitting between the catted and non catted bike which if is the case then Agostinis is wrong. Reliable info is hard to come by these days as all the older knowledgeable people in retail environments are being replaced by young "customer service" kids that don't actually know anything beyond year model stuff on a computer screen.  My bike has Agostini mufflers, Stucchi cross over and V11 header pipes fitted to a Daytona engine in a V11 Sport chassis. All fitted perfectly without any modifications. Can you imagine asking a modern parts person whether this combo would work? They'd spit their coffee across the room and have a coughing fit.

Phil

[Gmc28]

Phil, or anyone with info on this, I have a question:

I have the Agostini mufflers like Phil, then an agostini crossover that I installed several years ago. comically just realized last night while putting Red up on the stand for some winter work that the Ago crossover tapers down at the front (engine/input side) to receive the smaller diameter header pipe, and further that the header (stock) then goes inside of that already tapered down mid pipe (double step down, albeit not by much in either case).  All works fine, and has for years, but seems as though that’s a little goofy? 

Or maybe that's the way its supposed to be... Wondering whether the Ago or Mistral (or GTM?)  header pipes are slightly larger in diameter and fit over the tapered fit end of the (front of) the ago crossover pipes.  I suppose if I move the band clamp back and look at where the cut in the pipe is, that would be telling.

the example pic is NOT for a v11 (its for a v85), but shows in a slightly exaggerated way the tapered/reduced/male fit end of the crossover, like i have on the V11. with that cut on the mid pipe shown, it implies that goes on the outside of the header pipe, like what I have, though the taper implies it is reduced to accept a larger diameter header which would be on the outside.

Edited Tuesday at 02:25 PM by Gmc28

[Lucky Phil]

5 hours ago, Gmc28 said:

Phil, or anyone with info on this, I have a question:

I have the Agostini mufflers like Phil, then an agostini crossover that I installed several years ago. comically just realized last night while putting Red up on the stand for some winter work that the Ago crossover tapers down at the front (engine side) to receive a larger diameter header pipe, but i have the stock headers feeding in which are smaller than the tapered diameter of the Ago crossover.  All works fine, and has for years, but seems as though that’s a little goofy? 

Or maybe that's the way its supposed to be... Wondering whether the Ago or Mistral (or GTM?)  header pipes are slightly larger in diameter and fit over the tapered fit end of the (front of) the ago crossover pipes.  I suppose if I move the band clamp back and look at where the cut in the pipe is, that would be telling.

the example pic is NOT for a v11 (its for a v85), but shows in a slightly exaggerated way the tapered/reduced/male fit end of the crossover, like i have on the V11. with that cut on the mid pipe shown, it implies that goes on the outside of the header pipe, like what I have, though the taper implies it is reduced to accept a larger diameter header which would be on the outside.

Email Agositins and ask them about the header dia they are good to deal with. My bike uses std V11 Sport headers, a Stucchi crossover and Agostini mufflers and I have no tapered pipes at the crossover. May just be they wanted larger dia at the crossover and secondary pipes.

Phil 

[Gmc28]

48 minutes ago, Lucky Phil said:

Email Agositins and ask them about the header dia they are good to deal with. My bike uses std V11 Sport headers, a Stucchi crossover and Agostini mufflers and I have no tapered pipes at the crossover. May just be they wanted larger dia at the crossover and secondary pipes.

Phil 

thanks Phil -

sounds like a plan.  mostly just itching my OCD at this point, as it runs and looks fine, but struck me as odd.

If someone knows if the mistral header pipes are larger diameter, that would be of interest as well.

[audiomick]

8 hours ago, Gmc28 said:

..., it implies that goes on the outside of the header pipe, like what I have, though the taper implies it is reduced to accept a larger diameter header which would be on the outside...

All the exhausts  I have seen have had the "male" part of the fitting on the "upstream" side, and the "female" part on the "downstream" side. That strikes me as the only sensible way to build them. With the male part on the downstream side, it is almost certain to leak at the join, I would imagine.

[Gmc28]

33 minutes ago, audiomick said:

All the exhausts  I have seen have had the "male" part of the fitting on the "upstream" side, and the "female" part on the "downstream" side. That strikes me as the only sensible way to build them. With the male part on the downstream side, it is almost certain to leak at the join, I would imagine.

makes sense, and matches the reality that the cut ends, which are meant to be allowed to slightly squeeze another pipe inserted inside, are on the outside of my setup, which is to say the mid pipe that receives the headers has the cuts. 

It's clear i'm making more of this than it deserves.  But its dark outside, so i indulge myself, and still sits odd with me that the mid pipe narrows down/tapers on the front/intake side where it receives the header pipe, and that the exhaust is again narrowed slightly more (going forward) by the smaller header that slides inside that narrowed mid pipe.  maybe as phil says its by design, which is certainly something seen commonly on 2-stroke exhausts, but doesn't it seem slightly odd for these 4-strokers, to start narrower out of the head then widen out in 2 stages at the mid pipe? 

[audiomick]

21 minutes ago, Gmc28 said:

It's clear i'm making more of this than it deserves.  But its dark outside, so i indulge myself,

Well, I'm prone to that myself...

21 minutes ago, Gmc28 said:

... (going forward) ...

Maybe it would help to look at it from the other end, i.e. "going back".

It doesn't seem illogical to me at all that the pipe increases in diameter from front to back.

There are factors that I really can't judge relating to reflected pressure waves coupled with negative pressure at the head, resonance helping to suck out the gases, and so on, but the bottom line is "get that gas out of there".

It seems logical to me that the pipe is getting bigger towards the exit.

Edited Tuesday at 12:53 AM by audiomick

[GuzziMoto]

Something else you sometimes run into that looks like that is when an exhaust pipe has a dual wall. A dual wall pipe will be single wall at the point it meets another pipe, and then that sudden increase in outer diameter is where it becomes dual wall with a gap between the inner and outer walls. The Griso head pipes are a great example of this. The dual wall pipe allows a reduction in discoloration from exhaust heat. Not saying the pipe pictured is dual wall, but sometimes that is why an exhaust pipe looks like that. From a flow point of view it would be weird to have such a sudden increase in pipe diameter at that point in the exhaust system. That is oddly not something that would likely increase exhaust velocity. In fact, if it is a sudden increase in inside diameter of the pipe it would slow down exhaust velocity at that point. Which is generally something that would not help get exhaust out. But it can be very hard to estimate exhaust flow based strictly on looks. And given the simple nature of the V11 lump I am sure it is fine either way.

Edited Thursday at 06:20 PM by GuzziMoto

[Gmc28]

20 hours ago, GuzziMoto said:

Something else you sometimes run into that looks like that is when an exhaust pipe has a dual wall. A dual wall pipe will be single wall at the point it meets another pipe, and then that sudden increase in outer diameter is where it becomes dual wall with a gap between the inner and outer walls. The Griso head pipes are a great example of this. The dual wall pipe allows a reduction in discoloration from exhaust heat. Not saying the pipe pictured is dual wall, but sometimes that is why an exhaust pipe looks like that. From a flow point of view it would be weird to have such a sudden increase in pipe diameter at that point in the exhaust system. That is oddly not something that would likely increase exhaust velocity. In fact, if it is a sudden increase in inside diameter of the pipe it would slow down exhaust velocity at that point. Which is generally something that would not help get exhaust out. But it can be very hard to estimate exhaust flow based strictly on looks. And given the simple nature of the V11 lump I am sure it is fine either way.

agreed, and thats the main reason i let this very minor  “unsolved mystery” fester in my mind.  exhaust flow dynamics can yield all kinds of results, but it does seem very unusual to have a non-2-stroke motor with an expanding outlet/exhaust, except in oddball cases, like the “power bomb” chambers on some dirt bikes, etc.  The double wall thing certainly would explain things, though i’m guessing that mid pipe isn’t double wall.  it is worth noting that while the V85 mid pipe pictured above is illustrative of my V11, it isn’t quite the same and is definitely more extreme.  the V11 mid has a much milder expansion where the header and mid join.

i’m sure its all fine, though it’s still mildly of interest as to why that mid pipe slightly flairs to a larger diameter (on top of the fact that the header slides into and not over the mid pipe, making it a double step change in diameter as it flows downstream)