ok. ive been here for a little while now and see many people with "flapper mod" in the list of modifications in their signiture. ive never heard of this before this site. i know it's a airbox modification, but what exactly is it? how do you do it and what are the benefits?

 

Here ya go...... Read this > http://www.rogueracing.org/flap.htm

I know the article is for the 1000RR but the 929 has a similar system which is just as easy to sort in the same way,

 

so am i wrong in assuming that you approve of this mod? do you think that i would need to reprogram my power commander for the greater volume of air?

 

I made the `mod` to my bike after approx 2k miles before the RS5 Can and PC3 (now on 11k), and didn`t notice any major difference. I did improve a little with the mid range power delivery ever so slightly, I have just left it like that (only plugged the hose) never had any problems. So i do approve

If i where in your situation and wanted to do it i`d go ahead and see how it runs, if you don`t like it you just put the hose back in its original place. You don`t even have to take the fairing off. (Unless of course you want to remove all the p.a.i.r system completely)
I`m unsure if you`d need to tweek the pc3 settings but i don`t think it would need it.

 

I took all the guts out (including the flapper). The high speed benefit is nominal but off idle is greatly improved and midrange seems to be more responsive also. One note: if the 929's flapper is as hard to get to as the 1000 then I'd consider leaving just that part in -- what a pain to get to[:@]

 

how about for a 600? suggest, yes or no? and anyone have pics of the compete removal?

thanks!

 

CJ... the 600's do not have a flapper. So we are already "flapper modded"

Forgot to add.. the flapper is added to the 1000's and so on to help with passing noise inspections. The flap opens at higher rpm, but is closed at idle and lower rpm to help them pass sound test.

 

so is this the only reason that they exist? is there only power and throttle response to be gained when removing it? no downside?

 

None at all, I promise

 

I read a good write up (I'll post it later if I can find it) about this mod. The flapper is added to "create back pressure at low RPM" per Honda. Then the article went on saying that they have a really good source (insider at Honda) saying that manufactures of bikes have more trouble with passing noise requirements than emissions. The bikes have to pass a series of test including a decibels reading at idle and acceleration. So, with the flapper added, it restricts air flow to the air ducts and air box only at idle and initial take off. If you rev the engine up I believe like 5k or something the flaps will open ... but only if there is a load on the engine. SO no... If you sit and rev the engine, it will not open the flap. This will allow them to pass the decibels reading test. You will see a slight power gain if you do the mod or remove the system altogether because it will restrict a little air not matter what. I read where some actually cut the areas where the flaps were and put plastic back to make a nice smooth vent duct.

All of this is what I read when I was researching the mod for my 600RR, but we do not have the flap.