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two into one exhaust


Guest cliffy

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All things being equal, 2-1 ALWAYS produces more power than a 2-2 exhaust. The trick, as you note, is to get the math right. Some prefer the sound of dual exhaust, but dynos will prove the 2-1 to be functionally superior every time.

 

Good luck with the fabrication. The supertrapp style exhaust should be a very good choice!

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  • 1 month later...

I had a BOS 2-1 on my 1100sport inj.

The downpipes looked like BOS 2-2 or Termignoni or stock V11,they were 45mm od ,then came together in the middle behind the oilsump and from there on they were 50mm. od. The silencer was on the right side (Carbon) about 490 mm long.

Basically it looked just like a BOS 2-2 but with one silencer on the right side.

 

Preformance wise it was pretty good and it felt a little bit more brutal than the more even power delivery by a 2-2 with stucchi cross over.

 

important note,I never used it with a pcIII usb or a mapping on the chip with different fuel to the cylinders.I think that was needed on that model to get the best preformance.

Too bad i can't figure out how to post the dynorun but anyway:

Peak HP was 77 at 7000 rpm and torque was 83 nm at 6000 rpm with a small dip at 4500.

On the same dyno I got 74 Hp and 80 Nm with the 2-2 Stucchi set up.

I mainly exchanged it because there seemed no way to avoid the engine to stall almost every time on lo throttle after alot of throttle.

 

There are more successfull designs of 2-1 for guzzis i'm sure.

 

Regards

Anders

Sweden

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All things being equal, 2-1 ALWAYS produces more power than a 2-2 exhaust.

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Tell that to the Guareschi team who have had to go to 2-2 on their MGS for more power.

 

I seem to recall that the Ducati 916 family was 2-2 and the 999 has a 2 into a type of double muffler.

 

I don't think that you really mean ALWAYS. That covers a lot of territory.

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I have never heard an expert talk much about V-Twins and 2 into ones, but it seems to me that the challenge is to not have the cylinders interfere with one another.

To my mind it seems to be common sense that X crossovers will do better than H crossovers because the X can allow the exhaust gases to stay in the direction of the muffler ports.

For this reason, I believe the Stucchi crossover is the best for the V11.

Captain Nemo, AKA Enzo's cobra muffler nicely funnelled the two exhausts into the one muffler, so there was little restriction or cross interference between each cylinder's exhaust gasses.

I think if you follow that logic and make it loud, you will do fine.

But common sense can mislead.

I have considered going the other direction and doing a two into two with no crossover, so there would be no cross cylinder interference. And likewise go with pod filters for the same reason. The key being to make the filters big and the mufflers big and free flowing(ie.loud).

Otherwise top end power will be lost.

In anycase MotoGuzzi programmed into the ECU different fuel maps for each cylinder.

My guess is that this is primarily to compensate for the different air flows due to cross cylinder interference.

But we now have the capability to re-map each cylinder.

I think this is key to making a two into one work well.

I had a Quat-D 2 into 1 and it did not make great power above 5000 RPM.

I think with individual cylinder tuning and opening up the flow abit, it could have made much better power.

I am following JediOne's progress, hoping that he get more out of the QuatD.

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Guest jedione68
I have never heard an expert talk much about V-Twins and 2 into ones, but it seems to me that the challenge is to not have the cylinders interfere with one another.

To my mind it seems to be common sense that X crossovers will do better than H crossovers because the X can allow the exhaust gases to stay in the direction of the muffler ports.

For this reason, I believe the Stucchi crossover is the best for the V11.

Captain Nemo, AKA Enzo's cobra muffler nicely funnelled the two exhausts into the one muffler, so there was little restriction or cross interference between each cylinder's exhaust gasses.

I think if you follow that logic and make it loud, you will do fine.

But common sense can mislead.

I have considered going the other direction and doing a two into two with no crossover, so there would be no cross cylinder interference. And likewise go with pod filters for the same reason. The key being to make the filters big and the mufflers big and free flowing(ie.loud).

Otherwise top end power will be lost.

In anycase MotoGuzzi programmed into the ECU different fuel maps for each cylinder.

My guess is that this is primarily to compensate for the different air flows due to cross cylinder interference.

But we now have the capability to re-map each cylinder.

I think this is key to making a two into one work well.

I had a Quat-D 2 into 1 and it did not make great power above 5000 RPM.

I think with individual cylinder tuning and opening up the flow abit, it could have made much better power.

I am following JediOne's progress, hoping that he get more out of the QuatD.

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D-Laing,

 

Racer X and I will most definitly find more juice...

And will keep ya posted!

 

Keep me up to date on the two into one thread, I've always liked

that look and sound (But its gotta come out on the LEFT... Euro 80's look!)

 

And Happy New Year.

 

Jedi

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David, were you drunk on NYE?  :rasta:

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Atleast one of us made it to the Lookout :bbblll:

Since you have probably sobered up, what are your thoughts on re-mapping both cylinders when it comes to Two into Ones?

My guess is that the further your mods get from OEM, the greater the map changes need to be, and if you change the crossover or go to a two into one, you are going to change the cylinder offset requirements of the map.

Would you show us your left and right maps for your 2 into 1 and compare it to a left and right mapping of a bike with the stock crossover?

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Atleast one of us made it to the Lookout  :bbblll:

 

Dave , that funny little man apeing on your avatar it does distract the attantion from your posts I don't any longer read them :P:lol: ,even when you don't look at it your posts are all over with it. :lol:

The other one with the girlie was better. -_-

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Dave , that funny little man apeing on your avatar it does distract the attantion from your posts  I don't any longer read them  :P  :lol: ,even when you don't look at it your posts are all over with it. :lol:

The other one with the girlie was better. -_-

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Ok, I'll replace it.

But it is kind of fun to kick someone with it.

peepers.gifgeorge-bush-picture-39-713492.jpg

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