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when does the butterfly valve open on the midpipe on the 2010 brutales?

or is that even a butterfly valve in the midpipe?
 

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when does the butterfly valve open on the midpipe on the 2010 brutales?

or is that even a butterfly valve in the midpipe?
No butterfly/exup or any such valve in any MV mid-pipe Matey:)
 

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oh ok, thanks.

what is that spring thing on the bottom of the midpipe then right below the brake cylinder?

it doesn't appear to be any sort of spring cliip to hold the pipe connections its actually going into the midpipe.
 

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Haha

oh ok, thanks.

what is that spring thing on the bottom of the midpipe then right below the brake cylinder?

it doesn't appear to be any sort of spring cliip to hold the pipe connections its actually going into the midpipe.
It's called a Lambda sensor, or Oxy sensor for us normal people !
 

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The 2010 Brutales have both a Lambda sensor and EXUP 'choke' valve, not sure when it opens but usually around 4000 rpm.

'Engine performance has been optimized to improve drivability and power delivery, which are further enhanced by the new exhaust system, which has a choke valve operated by the injection control unit.'
 

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The exhaust tuning valves on modern bikes serve 2 purposes.

One is to smooth out the torque curve where exhaust pressure waves and valve overlap don't mate up well causing dips in the curve.

Second purpose is to help muffle sound at lower rpms where sound tests are done for emissions certification purposes.

Most high end sport bikes have ECM programming that varies the amount the valve is open to coincide with the exhaust pressure wave timing under varying throttle opening/rpm conditions. Not just an on-off thing.

If you always run at the peak of the torque curve (high rpm only...racing application) the valve serves no purpose, so race exhausts do not have them.

But if you ride in the real world you will find a lumpy torque curve in the mid-range if you just take the valve out.
 
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