Exhaust modifications, (Mistral)

[Formula Alfa]

Hello everyone,

I have a v11 le mans registered in 2007, so I believe it is one of the last models of its type with a lambda sensor fitted into the standard crossover box.

I have a few questions I would like to ask some of the more experienced members regarding exhaust mods.

I wondered if anybody has fitted the Mistral stainless steel reverse cone silencers along with their crossover pipe to the same model and what their opinions are on the results/benefits?

My questions are,

1,  If I take the plunge and treat myself to these items, will my bike run better without any further tuning, can I just bolt them on and enjoy?

2, Does fitting the crossover box as well as the silencers make much difference to how well the bike runs?, I am also  asking this question as my bike has a slight hesitation/cough between 2500 and 3000 rpm and If I invest in just the silencer`s might it help get rid of this or would I need the Mistral crossover pipe as well? (I appreciate a straightforward tune up that has been described here by Docc for example is probably a good idea to do first anyway, but I have noticed other members complaining of a similar hesitation, is the general opinion that this is a symptom of how the bikes have been set up from the factory to meet ever more stringent emission laws?

In the Uk, the main agent for Mistral seems to be a company called "Gutsibits" and the silencers and crossover pipe come to £804 so they are not cheap!, so if just fitting the silencers makes the bike run better along with the weight saving and better looks/sound I would be more than happy saving me £286, (the cost of the crossover pipe).

Finally, has anyone actually put their V11 on a Dyno before and after fitting these parts to see actually what gains there are in Horsepower and Torque?

Thanks in advance for anyone who can help, meantime I am saving my pennies!!

Formula Alfa.

 

[docc]

Those are some great questions!

Second question first: There are numerous contributors to the stumbling hesitation in the 2500-3000 rpm range. A well performed tune-up, not skipping any steps, goes a long way toward smoothing this out as much as possible.  Optimizing the components and connections of the charging system has also proved beneficial.

That said, @Lucky Phil so adeptly pointed out the (dramatic) ignition advance in that rpm range at very minimal throttle openings is problematic. (In addition @pete roper expertly reminds us that riding the Guzzi big block "sub-4000 rpm" is undesirable on a lot of levels):

Third question second: You can likely find a better supplier than the one you referenced. Worth trying.

First question third: The Decent Tune-up will have you assess the CO Fuel Trim setting and zero it if necessary. IIRC, this will necessitate disabling the lambda probe. FWIW, mySport ran better with Mistral canisters (with stock crossover) than with the rather restrictive, and heavy, factory LaFranchoni. Since my factory crossover is very special to me, I would never change it out . . .

[activpop]

@docc said...Since my factory crossover is very special to me, I would never change it out . . .

Is there a story to that?

[docc]

4 hours ago, activpop said:

@docc said...Since my factory crossover is very special to me, I would never change it out . . .

Is there a story to that?

Heh, well, yeah !

I realize not everyone has special attachments to things like the underside of their exhaust . . . 

[edit: a topic for another thread . . .   ]

[Formula Alfa]

Ok, thanks again for your help Docc, I appreciate your time.

Formula Alfa.

[docc]

17 minutes ago, Formula Alfa said:

Ok, thanks again for your help Docc, I appreciate your time.

Formula Alfa.

It occurs to me to have some fun approaching this in steps:

1) Decent Tune-up / Ride for a time.

2) Slip on the canisters of your choice / Ride for a time.

3) Decide whether to change anything / (like add a crossover) / Ride for a time

4) Meinolf your map / Ride for a time.

5) Ponder the outcomes / Post what you find / Ride for a time . . .

FWIW, I wouldn't expect any significant and measurable "Horsepower and Torque" gains, but would shoot for ride-ability and (how shall we say?):

BRIO !

 

[GuzziMoto]

Doc has excellent advice.

My two cents; Installing a free flowing exhaust is generally not going to fix any fueling related issues. If anything it will probably make them worse. If you have fueling related running issues I would either fix that or install the free flowing exhaust you want and then fix it, as installing a free flowing exhaust will typically require additional fueling corrections. No point adjusting things twice, if you want a better sounding exhaust run one and fix the fueling as required. GuzziDiag can allow you to make the required fueling corrections, after you have set all the basics as mentioned by doc in the "Decent Tune-up" comment. A better sounding exhaust isn't going to make your bike noticeably faster or more powerful. It can sound and feel faster and more powerful, though. And in the end, isn't that what matters?

[Formula Alfa]

Afternoon Docc, in your reply dated July the 6th, point 4, you suggest "Meinolf your Map",what does this mean?

Since I first wrote about this subject, things have progressed, I have now got my hands on some round section aluminum bodied Mistral Silencers which are now on the bike, they sound nice!!, although I have noticed the bike doesnt feel quite so urgent at low rpm anyway.

Since my bike is a late model with a lambder sensor, will the sensor  recognise the change in the exhaust system/ oxygen etc and talk to the ecu accordingly?, I am concerned it might lean out the mixture even more and make running worse

I have only been for a short run so far as it poured down with rain, but looking forward to a longer run today and will reflect at the end of it.

I hope to carry out some basic servicing over the next week, change oils/filters, gap some new plugs and check the valve clearances and then I will get a diagnostic tune up done based on your recommendations, still trying to find someone that lives reasonably near that may have guzzidiag etc, so if anyone is reading this from the uk and can help please let me know.

Will post a picture soon.

Regards,

Formula Alfa.

[audiomick]

39 minutes ago, Formula Alfa said:

..."Meinolf your Map",what does this mean?

That is no doubt a wink in this direction:

 

[docc]

Ah, yes, installing Meinolf's map may end up your best move. I would certainly perform the entire Decent Tune-up first and decide if you find it necessary to change the map.

I remain the poster child for the factory map being fine as long as the tuning parameters are seen to on a regular basis and the charging system is in good stead.

[Formula Alfa]

Thankyou Gentlemen.

Formula Alfa.

[Kevin_T]

Someone mentioned using a newer O2 sensor for improver drivability. They said the reaction time was so much quicker then the old model. Not sure if you go with tweaking your map by using trim. The computer might just override it with the O2 sensor.  Meinolf's map might be necessary that the computer is going to have a correct base value. My bike doesn't have an O2 so I might not know what I'am talking about.

[docc]

2 hours ago, Kevin_T said:

Someone mentioned using a newer O2 sensor for improver drivability. They said the reaction time was so much quicker then the old model. Not sure if you go with tweaking your map by using trim. The computer might just override it with the O2 sensor.  Meinolf's map might be necessary that the computer is going to have a correct base value. My bike doesn't have an O2 so I might not know what I'am talking about.

 Good point on upgrading the Lambda probe! That was brought to us in 2020 by valued member @ScuRoo. Check out the good stuff he reported to us in his thread:

 

[ScuRoo]

On 7/17/2023 at 8:13 PM, Formula Alfa said:

Since my bike is a late model with a lambder sensor, will the sensor  recognise the change in the exhaust system/ oxygen etc and talk to the ecu accordingly?,

Hi Formula Alfa

I missed seeing your post in regards to your V11 equipped with the O2 sensor which enables the 15RC ECU to efficiently autotune & trim lambda optimisation whilst in close looped rev range operation ie., constant throttle cruising - which is EXACTLY where the annoying hiccup stumble will appear breaking the glorious reverie in enjoying the moment

My bike is 100% hiccup free perfect - whether at 4000rpm, 3500rpm, 3000rpm, 2500rpm, 2000rpm - I can’t even squeeze so much as an experimental ‘hic’ out of it at any rev level

The annoying hiccup is but a distant memory. Gone.

Please read thru the thread that docc kindly inserted - it’s all there. Change out the factory O2 sensor to the LSH24 Bosch unit & Bob’s your uncle

Hiccup begone - & as a bonus - bike runs detectably smoother

[Formula Alfa]

Thanks ScuRoo,

Definately food for thought, if it doesnt cost too much to just swap over the o2 sensor for the Bosch one you mention, I might well do that before I get my tune up done.

Thanks again for everyone`s input regarding this subject, if anything I have received too much information.

At the end of the day, Just want the bike to run nice at all rpm, I`m sure I will get there.

What I have also realised is that you can get too hung up on stuff and if your not careful you can stress yourself out for no real reason,and spend a fortune for no real benefit, like almost everyone else though, I cant help myself and am constantly searching for the perfect bike to ride, I go through a cycle of aquiring motorcycles, I have too many to deal with, then I sell some, then I need some more, , its a complete addiction I have had for some time now !!

It seems to me, modern bikes are actually a real pain though with their more complex ecu`s/sensors/emission control systems the manufacturers are now obliged to install and yet, how much of an environmental impact do motorcycles have compared to other vehicles I wonder?, It doesnt really matter now what the level of pollution is, if it runs on a fossil fuel, its in the firing line whether it is a moped or a truck!, I have reached an age where I find myself hankering after older bikes now that I can still fiddle with, with relative ease, My next goal is to find a bike around 40 years old that is satisfying to ride and Tax and MOT exempt!

Anyway, went off subject a bit there!,  Once I have carried out further work to the Guzzi, I will report my findings.

Ride safe.

Formula Alfa.