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Fabricating a 2-1 exhaust


Bjorn

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does you bike have an O2 sensor? if so, did you make a new bung for it?

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Yeah I can drain the gearbox without removing the pipes :)

 

And the centre-stand still fits, just not in the pictures.

 

@sp, Yes my bike has an lambda sensor. I turned it off anyways since it fucks up the ride. Dont really plan on fitting one on the new set-up. To my surprise the ride ability was not affected negatively by the new setup. However i will still have the bike dynoed by the end of this month.

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Very cool! Seems to me though that eliminating the sensor is kind of a loss. Would it be that hard to weld in a piece of M18 x 1.5 threaded tubing? My GPR has sensor bung. Which is where I am going to place a Bosch wide band O2 sensor to go with a Power Commander V with Auto Tune. I didn't have this on my stock '01 exhaust, which was one of the benefits for me of upgrading. Improving functionality, or in your case - retaining it, is always a good thing, in my opinion.

 

EDIT: something like this – http://www.ebay.com/itm/M18-x-1-5-mm-Right-Hand-Threaded-Insert-Tube-Adaptor-/180555767232

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While I agree that when coupled with some sort of wide band sensor and fuel modification based on that wide band sensor is a good thing, the stock set up with the narrow band sensor and fixed adjustment tables is somewhat lacking and probably does not actually help the motor run better.

I had a Buell a while back with the OEM MM fuel injection set up. It was one of the best stock EFI systems I have used. The original map was a bit off but they quickly loaded a new map and the bike ran perfect. It also was a very smart system and you could feel it learning, say when you did something like swap exhausts. It would, at first, run a little rough but you could feel it smooth out and improve as you ran it through the gears a few times. The Guzzi system, even on the latest Guzzi's, is no where near as good. I do have a PCV with AutoTune on my Griso and it works well enough. But the system on my Buell did all that stock. The PCV/AutoTune set up is $$$. Running a fixed map set up with the stock narrow band sensor taken out of the loop (so to speak) could be a viable option for proper running for a lot less money. The main thing the narrow band set up brings to the table as used by Guzzi is reduced emissions. It does not really make it run better, smoother, or make more power.

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Sure, I'm not arguing that the stock Guzzi setup is any good. What I'm saying is that if you are going to go to the trouble of building yourself a new exhaust system from scratch, it's a shame to lose the ability to plug in a sensor, especially when it's relatively easy to do comapred to the complexity of the overall build. That's all. I supposed it wouldn't be a big deal to add one later either.

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... The main thing the narrow band set up brings to the table as used by Guzzi is reduced emissions. It does not really make it run better, smoother, or make more power.

 

I think this is the only reason there is a lambda sensor on the bike from the factory.

 

Fabrication wise its not a problem to fit a bung with sensor. However im not familiar with a wide band sensor, let alone tuning it. The way I see it is the engine has mutiple sensors like oil temp, air temp, throttle position, RPM and so on. The sensors help the FI system to ensure a proper setup. The lambda sensor is just one of them, and i dont like the stock sensor.

I will get the bike dynoed with this new exhaust, leaving all the sensors but the lambda do their jobs. I dont see why that wouldnt work.

 

Comparing the guzzi setup to a carburator bike, which has a fixed setup I dont think its all that bad.

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Running FI open loop (without an O2 sensor) is not the end of the world and should work well enough as long as the map is right.

The cool thing about closed loop is the way it can correct a map that is not quite right. And, as I mentioned, watching my Buell correct the mapping after changing out the exhaust system was awesome. And that was with the stock narrow band O2 sensor.  If only my Guzzi FI were that smart (actually, it is now, but that was only after I spent a large chunk of money on adding the PCV and A/T). I am a carb guy at heart. But I do see that FI has the potential to work much better then carbs and I do my best to embrace FI. To butcher a marine corp expression, you have to adapt, learn, and sometimes improvise.

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The buell part sounds nice, I thought such stories about ''self learning FI systems'' were BS. Apparently it is possible. shouldn't this get all the injection specialist out of business? 

Even without getting my bike tuned with the new exhaust, it does not feel bad at all. I just want to get it right and dont want to leave loose ends :)

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As per my conversation with Todd at Guzzi Tech, regarding the PC-V/AT:

 

me: So in theory, with this box I can change my setup (exhaust, intake, etc.) and the fueling can be changed accordingly, and I can have a map for each setup? For example, I have removable baffles in my muffler. I could have one map for it with the baffles in for street use, and another map with the baffles out for track use?

 

Todd: Even simpler… AutoTune will correct automatically for whatever changes you make (sometimes with a couple extra short rides & key strokes). I’ll help you through it. It’s amazing technology.

 

me: so no need for dyno sessions either?

 

Todd: Nope.

 

me: Awesome. THAT alone is worth the price of admission. Although I am curious to know how much she actually puts out...

 
Todd: Yes it is, and seeing numbers is fun (though often disappointing).
 
(bold emphasis is mine)
 
With all due respect to everyone on this board, I would go with Todd's opinions and expertise regarding fuel injection technology and how it relates to the power output of Moto Guzzi engines.
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Well, as mentioned, my Griso has a PCV and A/T (from Todd) and it works well. The wifes V11 has a PC3 with a custom map that I have since modified (as I found the custom map a little lacking in certain drivability situations). I had a really good custom map for it but when I got the heads done I took it to a different tuner (the first guy was gone) and forgot to pull the first map out and save it before the next guy took a stab at it. He did not do as good a job as the first guy (perhaps part of the reason he was gone, he spent way to much time on the wifes bike, great for me but bad for his bottom line) so I had to adjust it. A PCV with A/T would have taken care of that for me but they did not make them back then. But while I love the PCV and A/T idea (especially the A/T) I would not say it is the only way to get a well running Guzzi. I don't think the Guzzi lump is that finicky of a beast and a custom map could work just as well, perhaps with a ittle more effort then the A/T. But the A/T method is not without its fine tuning. You need to tell it the correct target air/fuel ratios to get the best out of it. WHile someone like Todd can get you very close, there is still room for fine tuning.

 

The Buell was great as far as FI goes. Personally I think that the map they loaded in after the first one did not work well was not EPA legal. I think it was not lean enough. But it did work well and watching/feeling it correct the fueling was great. I wish other makes would work that well. The funny thing was I believe it was Weber/Marelli FI. Clearly they know how to make it work, why can't they make the one on my Guzzi work that well?

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