Re: Flapper valve mod
Posted: Sun Feb 26, 2012 1:59 pm
steve p wrote:power gains from either mod are so negligable but removing the PAIR system reduces engine clutter and a bit of weight. To benefit the small amount by the flapper mod you really need a Power Commander with a custom map as you are messing with the air flow. My bike really did run the best before i did either mod and put K&N's in, but the induction noise is nice through the snorkel. Have a look at the engine upgrades on this site and it will give you an idea of what mods go together to give a ballanced result.
http://www.revolutionuk.co.uk/
I did it on my own and cocked it up costing money to pull it back. The flapper and PAIR mods wont do any harm but could be the start of the downward spiral especially if like me you listen too much to the American forums about changing the airbox and snorkel as a "must do extra 10bhp".
The chap at the above link pointed out that these air box mods are pointless unless you get all this extra air into and out of the cylinders thus requiring porting, gas flowing and reprofiled cams. Then you need to get rid with a high flow exhaust. The stock bike has been designed as a ballanced system so if you alter any of it too much it cocks up the optimum flow, and you dont get owt for nowt.
But i would probably do it all again
Forgot to say that if you do the flapper mod you may as well take it out completely and chop out all the excess plastic indide the snorkel, it really does open it up
The only problem with taking all the bits out is that it spoils the value of the bike for what benefits you actually get considering taking the pipe off is almost the same. And I know, we hear it all the time "I'll never sell my bike", and I see this all the time on other forums and folk do sell their bikes.
Its like cleaning out the garage, "I'll not ever need that" and the minute you toss it you find a need for it.
The bike has more than enough power for most of us, fit a set of nice exhausts, a power commander to take out the rough edges, get it dyno'd and enjoy it for what it is. If you want to go faster buy a Ducati if you can live with them falling to bits, or a busa.