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Mistral exhausts

Jenko

Jenko

Tuned and Synch'ed
Joined
Feb 15, 2016
Messages
97
Reaction score
31
Location
Shropshire UK
image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg just in case anyone is deciding which aftermarket silencers to fit, here's my opinion so far on Mistrals.
I just swapped my originals to Mistral Shorties. They are slightly less than half the weight. Swapping took about half an hour, then another half hour to polish everything!
For your info, I've put some photos here.
They have removable baffles, and they sound excellent with or without.
I also changed the air filter for a K&N and I ordered the reflash kit from Todd. It runs ok with the baffles in, but not without, but I'm hoping that will all be sorted once I've reflashed. Cost about £1000 for all this, but I bought the Racer for £1600 off list price so I reckon I'm about even still!
 
Jenko you are gonna love riding it with the baffles out, love my Mistrals. Interested to hear how you get on with the refashioned kit on a UK bike. Keep us updated. ☺
 
Nice to see someone in the UK modding with Guzzitech. Hope UK import taxes arent screwing u they did when I bought a heated vest and gloves from the US. How does the reflash kit work ? Do you flash using kit from Guzzitech? Be intereting to see how a V9 map works if it inreacts with the traction control. Like the ida of switching a V9 from 47BHP (A2 licence) to whatever a tweaked map can do.
 
nel said:
Nice to see someone in the UK modding with Guzzitech. Hope UK import taxes arent screwing u they did when I bought a heated vest and gloves from the US. How does the reflash kit work ? Do you flash using kit from Guzzitech? Be intereting to see how a V9 map works if it inreacts with the traction control. Like the ida of switching a V9 from 47BHP (A2 licence) to whatever a tweaked map can do.
Click to expand...

Well, I've bought stuff from US before and been hammered with taxes, but Todd knows how to avoid that.
I believe that the flash computer he sends reads my mapping, downloads it onto my laptop, then I email it to him and he sends me revised mapping via email. I then download it onto the flash computer and then transfer it to my ecu.
It's the V7ii, not the V9 though. I'm hoping that it does the same level of transformation that a similar modification did for my Bonneville. That bike is an absolute joy to ride now, and really quick. I recently test rode the new 1200 Bonneville and decided not to buy it because my modded 865 is as quick, and definitely as torquey.
 
I changed to Mistrals as well. Nice set for the money in comparison to some others. My bike ran okay too with the baffles in but the reflash makes it all feel so much smoother thru acceleration. The weight savings is fantastic and really cleans up the look of the bike IMO.

IMG_5861_zps656wrwna.jpg

IMG_5860_zpsaovgkigz.jpg
 
Well, I got the GTRX reflash kit from Todd, followed the really easy instructions and sorted it.
I have to say, the techno bit was worrying me, but it really is easy. I'm so useless at computer stuff normally, but this was easy.
So, what's it like to ride? Well, honestly it feels like a different bike. With the baffle-less Mistrals it sounds absolutely fantastic, not in a male-menopausal type of way like open-pipe Harleys, but it sounds like a deep rumbling throaty sound, until it hits the top end of the rev range, then it really howls. Apart from the sound, which is a side effect really, the throttle reesponse is so much improved that it really feels like a different engine. It feels like I expected the V9 to feel, but didn't. It has lots more torque, lower down the rev range. The fuelling is sweet right from cold starting to hot thrashing. It's much nicer to ride, whether I'm pottering about or being a bit more throttle happy. The improvement is difficult to do justice to on a forum, you have to ride it to feel the vast difference. I actually got the front wheel to lift a little!
All in all, it's cost a fair bit to get the V7 running and sounding like my 1996 Guzzi 750T !
Just over £600 for the Mistrals and K&N filter and postage. Then the cost of Todd's re-flash computer (£430) was bumped up by UK Customs, and by the UK Post Office who charged me a combined price of £55 to get it into the country!
Even though it was over a weekend, and Todd was busy, he got the reworked mapping to me in a very agreeable and realistic timeframe.
Was it worth it?
Absolutely.
Riding a bike like a Moto Guzzi V7 or a Triumph Bonneville (my other bike) is all about the feeling that I get from it. Not the timewarp top speed or the twenty different electronic rider aids and modes. And these modifications have hugely improved the riding experience.
I test rode the V9 and the new T120 Bonneville and neiher of them are much of an improvement over my V7 and my older Bonneville, thanks to better exhausts, air intake and remapping.
One happy customer!
 
Shame you did not first try the simple way of improving the bike by removing the lambda sensors (with the standard map) ........then fitting Todd's map (with lambda sensors reinstalled?).
I would be really interested in the comparison.
AndyB
 
andyb said:
Shame you did not first try the simple way of improving the bike by removing the lambda sensors (with the standard map) ........then fitting Todd's map (with lambda sensors reinstalled?).
I would be really interested in the comparison.
AndyB
Click to expand...

I can't see how removing a sensor that sends info to the ecu would improve the ecu's performance? Surely it would just run even worse. The Lambda sensor supplies info that then changes the fuelling system. If it wasn't needed, it probably wouldn't be there! As far as I understand, the standard map is set to run lean to pass emissions legislation, so removing the sensor wouldn't change that.
I'm a bit confused why you think that would work? If it does, maybe Todd could have saved himself a lot of research and work developing the GT RX system maps?
 
Hi Jenko,
A bit of a guess based on what I have read, but here goes....

MG design the bike with an appropriate ECU that makes it run properly throughout the rev range.
They then have to meet Euro 3 emissions tests.
So they add the lambdas which lean off the mixture low down. This allows the bike to pass the Euro 3 tests....but makes it run poorly below 4000rpm when the ECU is in closed circuit with the lambdas. However, higher up the rev range the ECU runs in open circuit so the lambdas have no effect.....so max power is not changed and on paper the bike is just fine. Until you ride it and discover the low down fueling issues.

So - remove the lambdas and the ECU is back to how it was originally designed to run...in open circuit throughout the rev range (just like a carbed bike).

Removing the lambdas transformed my bike (standard air filter and Mistrals with dB killers fitted which seem to give similar back pressure to the standard silencers). So basically a standard bike.
Your bike has a different air filter and no db killers in the Mistrals and these changes will tend to make it run leaner, so so Todd's map may be needed.

But I would still be interested in comparing our two bikes and how the engines now perform.

AndyB
 
What if I'd done it as you suggested, tried it by just removing the Lambda sensors, then after changing the mapping with Todd's reflash gadget, and found no difference? Or even worse, that the simple Lambda removal was better?
I would have spent best part of £500 for no benefit! No, i think I'd rather just be happy with what I've done, otherwise I'd feel a bit gutted
 
Jenko said:
What if I'd done it as you suggested, tried it by just removing the Lambda sensors, then after changing the mapping with Todd's reflash gadget, and found no difference? Or even worse, that the simple Lambda removal was better?
I would have spent best part of £500 for no benefit! No, i think I'd rather just be happy with what I've done, otherwise I'd feel a bit gutted
Click to expand...
Don't worry the way you did it is the right way. It's been discussed elsewhere.
 
nel said:
Nice to see someone in the UK modding with Guzzitech. Hope UK import taxes arent screwing u they did when I bought a heated vest and gloves from the US. How does the reflash kit work ? Do you flash using kit from Guzzitech? Be intereting to see how a V9 map works if it inreacts with the traction control. Like the ida of switching a V9 from 47BHP (A2 licence) to whatever a tweaked map can do.
Click to expand...

Yes I got screwed by Post Office and UK Customs, total of £54 surcharges!
The Guzzitech Flash kit was really easy, and works a treat.
Just remember that Todd lives in the States, and there's a hell of a time difference, so you may not get the quick email replies that some US customers have quoted. It would be a bit unfair to expect him to reply with your new maps in the middle of the night!
As far as I can tell, it hasn't interfered with the traction control, I can still switch it off, which I do most of the time.
 
andyb said:
A bit of a guess based on what I have read, but here goes....
Click to expand...
Lots of guessing. Visit a air/fuel load-cell dyno and really see what it does. Newer MG's are pricey investments and/or repair costs to run on guesses. Please don't devalue my work with such opinionated statements such as this on this Forum.
 
GT-Rx® said:
Lots of guessing. Visit a air/fuel load-cell dyno and really see what it does. Newer MG's are pricey investments and/or repair costs to run on guesses. Please don't devalue my work with such opinionated statements such as this on this Forum.
Click to expand...

Well said!
 
Anyway, I tried it today with the baffles in, and before doing that I opened the inner hole in the baffle out to 10mm.
It sounds ok, not really much quiter than without the baffles at tickover, but higher pitched.
No problem with the fuelling, it runs smooth from cold, no hesitancy or fluffing til it warms up, like the standard setup.
With the baffles fitted it seems to lag a bit at the mid to top end, but only a little.
I'm going to remove the baffles and run it like that. Sounds deeper and meatier, and I think it feels like it has more low down torque, although that could just be an effect of the sound, if that makes any sense. It sounds so meaty at low revs that maybe that is influencing my interpretation of the performance.
Either way, baffles in or baffles out, it is much much improved over stock mapping, and sounds much better.
It's no quicker at top speed, as far as I can tell, but I haven't spent much time over 100mph.
Getting up to speed is definitely improved, as is low down fuelling, and that's what I was expecting.
Thanks to Mistral, K&N, Todd at GT RX, and to my employer for paying me money to spend on my toys!!!
No thanks to UK Customs or UK Post office for charging me taxes on something that I spent my own already pre-taxed earnings on.
 
Well done on an optimised racer. MotocycleUSA reviews agree that US/canada mapped bikes get 2HP over Euro4 bikes. That before de-cat and free flow exhaust. The flat valves restrictive flow has got to like those mistrals. I'm guessing V7 herons are finished in the UK with Euro4. Discounts are going to be needed to clear stock. Like the stornello. the cat is in the mid section link pipe. Wonder is it can be decated.
 
I thought that there is a cat in each silencer? Certainly feels heavy enough. If it was in the crossover pipe, surely the gases would just take the easier route, straight through the silencers?
Euro4 has done a lot to screw up a lot of engines, in my opinion.
(Remaining content removed by Jenko due to offending Mr Pootle)
 
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Jenko said:
I thought that there is a cat in each silencer? Certainly feels heavy enough. If it was in the crossover pipe, surely the gases would just take the easier route, straight through the silencers?
Euro4 has done a lot to screw up a lot of engines, in my opinion.
Now that the UK is out of the EU, I wonder if we can disregard some of these nanny state rules?
Click to expand...
Yes, let's get pollution levels up again. Damned EU. There's nothing wrong with raw sewage on our beaches, either.
 
Mr Pootle said:
Yes, let's get pollution levels up again. Damned EU. There's nothing wrong with raw sewage on our beaches, either.
Click to expand...

Whoa Mr Pootle, chill out!
I did say SOME of the nanny state rules, not all. I don't think anyone wants this forum to degrade itself by turning political, so I apologise for mentioning it.
Maybe I should completely refrain from voicing any personal opinions about anything, and just stick to technical issues, after all, that is what this forum is about. So on a technical note, maybe all motorcycle petrol engines should be banned, and only electric scooters allowed?
I'll try to edit my original post and remove the offending sentence, but if I'm unable to do so, please ignore it.
 
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