Flapper Mod

[TarkMalbot]

Right.

I have had many questions asked to me about this and different opinions about it so I thought I would start a topic just about it.

Can anyone explain what the flapper does, why it was installed by Aprilia if it runs better without it, how to do the mod and any problems or comments people have had running it.

Cheers,
Mark.

[rsvr47]

Mate this opens at 3000 rpm (I think) it allows more air to flow in to cool the engine and enhancing performance. HAving spoken to a chap at Aprilia Whitehaven He said take it out gives yuo a few more BHP. When ui took the bike to Southern Cross for the renegade carbon air box and quizzed him he said unless your racing constantly as in that is all you use the bike for leave it, it will make no difference at all. That guy at southern cross has won the sound of thunder racing and a hell of alot more so i think mine will be staying..

[V8-Powered]

If you are running a Rene airkit, which I think your bike is, it will not make any difference anyway as their is no airbox to be pressurised.

[TarkMalbot]

I have an Evo kit it the bike and I know Don well. I even beat him in the MRO Supertwins. LOL.

[V8-Powered]

If you have the EVO kit, you may end up gaining all of 1bhp for the mod...

[TarkMalbot]

is the Renegade and Evo kit different in principle? Whats the difference?

And is this flapper mod only making a difference after 3000? And if so whats the point as most of the time I am above that anyway.

How does the flap work? Ie when the engine revs build up does it create more vaccum enough to open the flap? Although this way pulling off the tube and blocking it would mean the flap never open so I am guessing this isn't correct...

[V8-Powered]

Rene kit totally replaces the stock air box and filter putting a bloody great big ITG / Piper-X filter on a carbon base in its place, the EVO removes the stock air box lid and and makes a seal against the underside of the fuel tank, doubling the air box volume.

Most people see the flapper mod as pointless but still do it anyway, just say they can add it to the mods list.

The flapper servo is controlled by the ECU but I believe the flap itself is vacuum operated, so if you do pull the pipe remember to block off the hose.

[rs3 mille]

the flapper mod on the new models is vacuum operated