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Discussion Starter #1
Anyone know anything about these stacks? All i could find out was that were offered through Motocourse.jp at one time.







 

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From memory (and it's 6am as I type this) the OEM plastic velocity stacks have these "holes" drilled on the inside surface too. They are effectively dimples, not holes right through the velocity stack given their position on the velocity stack and will not let unfiltered air into the manifold. They are probably to disrupt linear airflow (guessing).
The red ones pictured here also have the dimples on the outside and I'd suggest that's because Motocorse put these little dimples in lots of their billet parts.
 

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From memory (and it's 6am as I type this) the OEM plastic velocity stacks have these "holes" drilled on the inside surface too. They are effectively dimples, not holes right through the velocity stack given their position on the velocity stack and will not let unfiltered air into the manifold. They are probably to disrupt linear airflow (guessing).
The red ones pictured here also have the dimples on the outside and I'd suggest that's because Motocorse put these little dimples in lots of their billet parts.
They look like holes to me. Look at the one that is in focus and it looks like light coming through the hole.

Yeah I'm not getting the point of the holes in the sides. Wouldn't that just let in unfiltered air ?
Check out where the holes exit and it is above the rubber seal so it will be within the airbox, but I'm not cleaver enough to know what they do.:wtf:
 

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My guess is that the holes decrease pressure fluctuation around the trumpets and may also help to maintain the integrity of the rubber seals.
 

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They look like holes to me. Look at the one that is in focus and it looks like light coming through the hole.



Check out where the holes exit and it is above the rubber seal so it will be within the airbox, but I'm not cleaver enough to know what they do.:wtf:
Well spotted - yes I see it now, it's a hole right through and it's effectively a dimple because of the outer rubber cuff sealing against the air box.
 

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There was a difference in height between early 750 and Evo3 750, Evo3 were shorter for more power at higher rpm, some bikes (inc Tamburini with moveable inlets have different length ones on cyl 2 and 3 compared to 1 and 4.

I saw a Triumph triple at the race track with 3 different length trumpets, don't know whether that is std or not.

They look much shorter than the std 1000S bikes trumpets
 

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Boy that's some pretty jewelry. They look like they have a nice smooth junction with the throats. Unless the stock ones have a rough junction I see no need for them. You just want the smoothest surface for flow through the tract. Length matters but I doubt these are so far off stock you'd notice the difference.
 

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Discussion Starter #11
Hmm, figured there would be some more info within the agusta community.
They are a bit wider than the plastic stacks i have, but don't know if the ones i have are oem stock or a race version. Anybody have some known oem stock velocity stacks they can measure the height for me?
 

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Joe, why not paint the ones you have blue? Seems an easier way to go about things if color is the main purpose :stickpoke
 
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