Muffler choices

[ponti_33609]

Hi - Just a question that I did'nt see in this "old" running thread.

 

Has anyone simply tried polishing the stock, brushed aluminum cannisters? I have seen some heads done and they look really good and was curious if the same could be done with the original cans?

 

Bob

[Skeeve]

Hi - Just a question that I did'nt see in this "old" running thread.

 

Has anyone simply tried polishing the stock, brushed aluminum cannisters? I have seen some heads done and they look really good and was curious if the same could be done with the original cans?

 

Bob

 

V11 owners generally desire to replace the stock can w/ aftermarket because:

 

-A- The stockers are pretty darn restrictive

&

-B- They weigh a ton!

 

Losing 10# of excess baggage is like getting a free pony... let alone any slumbering ponies that may get woken up w/ less exhaust restriction!

[ponti_33609]

V11 owners generally desire to replace the stock can w/ aftermarket

 

I hear you. I love the look of Staintunes but really expensive so was curious if anyone has dressed up the stock. I have also seen them with Jet Coat that looks good but if I am going to invest about 150.00 I REALLY should get aftermarket ones.

 

Bob

[FASTFREDDY]

Being as cheap as I am, i modified my stock mufflers. Shortened about six inches, straight thru glass packed design. Great sound at a very low price. And still looks stock, which I like.

[Skeeve]

Being as cheap as I am, i modified my stock mufflers. Shortened about six inches, straight thru glass packed design. Great sound at a very low price. And still looks stock, which I like.

 

Interesting that you shortened the stock cans 6" (15cm for our metric friends), as the Staintunes are about that much shorter than the stock cans...

 

Is that a custom paint job on your LeMans? I've never heard of Guzzi offering them in mint green?..

[ponti_33609]

Interesting that you shortened the stock cans 6" (15cm for our metric friends), as the Staintunes are about that much shorter than the stock cans...

 

Wow, nice job.....any pic's of in-process? Was it difficult?

 

Bob

[FASTFREDDY]

Wish I woulda taken in progress pics. Alas I did not. It's not hard to do, just very time consuming. I've done two sets so far. I slide the cover off, cut the ends off, drill spotwelds out, split the case down the seam, remove guts, reweld seam, weld front cap, fabricate perforated tube, install tube, pack, weld back end cap on, trim cover to fit, bore out hole in decorative endcap, and voila!, done.

 

The color is off the custom BASF color chart called Peridot. The pictures don't do it justice.

 

BTW, this is by far the best bike I have ever owned in 34 years of riding.

[motoguzznix]

Hi - Just a question that I did'nt see in this "old" running thread.

 

Has anyone simply tried polishing the stock, brushed aluminum cannisters? I have seen some heads done and they look really good and was curious if the same could be done with the original cans?

 

Bob

Hi Bob

 

I did

You have to remove the silver coating first (mine were silver) which adheres very good. So this was a sweaty job. Then treat the cans with wet sanding paper beginning with 150 and up to 800 - 1200. The finish has to be done with a polishing disk and wax. Then the cans are really shiny and you are as dirty as you ever can be. I also polished the headers and the crossover. Looks really fine. Especially these are much better to keep clean when polished.

 

I also modified the cans for better flow. The mods are described in the "open the stock cans" thread that can be found with a little search.

[ponti_33609]

Hi Ernst,

 

Very interesting...yes it looks like a annodize of some sort. You do not have a picture do you? Would love to see it!

 

Bob

[motoguzznix]

Hello

 

Sorry for the low quality of my pictures. I hope you can get some impressions fron the cans.

If you are interested, I can add some pics from my can modification that support the writeup in the "open the cans" thread. The mods are quite simple if you are able to handle a saw and a welding device.

 

 

 

Ernst

[ponti_33609]

Hi Ernst,

 

Thank you for the pic's. I like the look so much better than the muted looking stock ones. Yes, this is something I would like to undertake. I have a set of black annodized ones that I will work on while I use the ones I have on my bike. Would love any other insights you might have. You left the sleeve on the exhause while polishing or did you slide it off?

 

Thx again,

Bob

[motoguzznix]

Here the description of my modifications taken from the "unpacking the cans" thread. There are also some power and A/F measurements included.

 

My mods: The idea was to let the gassses pass the muffler without changing the direction. Originally, the gas enters through to to chamber 3, turns back to 2, 1 and back out via the very long end tube.

In the first chamber I cut' out 50 mm from the tube which enters from the collector. (On the mufflers I modified, there was the catalytic converter in that place).

The 2nd chamber remained untouched.

In the 3rd chamber I cut' out 50 mm from the upper tube which goes out.

The 4th chamber with the steel wool remained untouched too.

So the exhaust gas flow finds an open end in chamber 1, passes to chamber 2, 3 and can leave from there via the much shorter end tube. No change in direction.

 

The changes can be seen in the upper schetch below:

 

The modifications are easy to perform, see some pictures taken during the work:

I cut' a window in the 3rd chamber from front

 

the end tube will be removed from there

 

The front cap will be sawed off just behind the welding

 

the end piece of the end tube will be cut' off, from the thick lower tube where the gas enters must be cut out by 2-3 inches

 

The power comparison on my own bike - the upper two curves show the influence of the exhaust mods, no other changes.

Power graph

 

On an other bike the gains were even bigger:

 

The two lower curves show the influence of the mods on the same bike with stock mapping - the 3rd upper graph is a bike with additionnal mapping changes and a different exhaust. Sorry for the low quality of the picture - the scan wasn't better.

 

These mods are easy to perform - it took me about two hours for the second pair of mufflers. Welding the mufflers is most time consuming - depends on your practice.

[jimbemotumbo]

Here is proof that old threads never die.

Since this has come up again, I have a question for Ernst:

 

What exactly is the benefit of this mod?

 

I think the issues surrounding unpacking the cans have been well covered in this forum. Kudos to your ingenuity Ernst, but I do not see that this approach solves any problems. You still have a very heavy exhaust system, and no change in performance. Yes, the dyno sheet you supplied appears to show very slight increases in power, but I suspect this has more to do with the temperature change recorded on each run. I could be wrong, of course. It's happened to me once or twice before.

Is there an improvement in sound quality / tone? Perhaps an improvement in throttle response that may not show up on the graph?

 

I think most of us around here would need significant improvements to consider such a permanent change when it may limit the opportunity to do the occasional track day, or perhaps attract the attention of law enforcement if it turns out to be too loud. The latter is becoming MUCH more common in all regions, and excuses likely fall on deaf ears when the officer spots the silencer welds. So, a not an impossible thing here ... I'm just not sure I see it happening with this mod.

[motoguzznix]

you are right concerning old threads

 

Since the early days of the "open the cans" thread I modified another V11s exhaust cans in the same way. This bike responded even better than my own V11 on the modification. Additionnally I took some photo shoots during the work. This convinced me to post the results again.

 

The gains are not so small: 3 RWHP on my bike and 4.5 HP for the second bike. And you can feel the difference while driving, it's not just dyno figures. 90 % of the aftermarkeet cans that are fitted to the V11s around do not show any bigger gains without A/F ratio changes. But my modified cans did also benefit from mapping changes: Torque climbed from 8.8 to 9.5 mkg, max power was about the same but the gains between 5k to 8k were up to 6HP. When I fitted open Leovinci cans, neither max power nor torque was any better, only the torque minimum at 4000 was slightly up from 7 mkg to 7.5.

 

But you still have the heavy stock cans. It depends on you if you like the looks or not. The modifications are unvisible from outside as all the welding seams are underneath the oval light alloy covers. There is everything written on the cans an officer likes to see and they will never arouse suspicion as they are only marginally louder than stock - slightly deeper tone and even at high rpms just a bit louder. That's because the complete volume of the cans is still used for noise reduction while flow resitance is reduced a lot. And weight helps reducing noise.

 

There is only one disadvantage: you can't bye it cheap on ebay. You have to du some work yourself. Not everyone is able to do this and not everybody would like it. But for those who can and like to spend the 2 - 3 hours of time there are good gains for your .