Inlet manifold

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acerigger
Posts: 5
Joined: Sat Jun 30, 2012 5:31 am

Inlet manifold

Post by acerigger »

Does anybody know what the function is of the restrictors in the intake below the carbies? I've never seen it before.

http://www.billzilla.org/VTR1000-restrictor.jpg
tony.mon
Posts: 16290
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Inlet manifold

Post by tony.mon »

They act as a sort of venturi, forcing the air to speed up as it passes through the restriction.
I think that it may be to try to reduce the airbox cough, but if so, it doesn't seem to work....
On a general principle of easy air flow in and easy exhaust gas flow out being best, they are often removed, you can just pull them out with a pair of pliers.
Ideally the insides of the inlet rubbers need to be smoothed out, giving a clean inlet tract with no steps.

However there's no power gain, or loss for that matter, and the weight saving is really negligible. You won't notice any difference.

Sometimes they have been disturbed and sit eccentrically in the throat, sticking out more on one side than the other.
It's not falling off, it's an upgrade opportunity.
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