Flapper valve and Dino Question

In the spring I'm gonna have the VFR dyno'ed and mapped, I have a PCIII, K&N, slightly modified exhaust and the flapper valve dis-connected.
My question would be: do I leave the flapper valve stock, or dis-connected?

Any input would be good (be it good or bad!)

 

I can only speak for mine, a 5th gen.Y2K model. I disconnected-opened- the flapper valve and I think it lost responsivness.After a few weeks I hooked up
the flapper door and the bike seems more responsive especially in the mid range. eddie

 

What is the flapper valve? Is it the one on top of the airbox lid?

 

yes, it is controlled by a pnuematic actuator with the vaccum controlled by a selenoid, controled by the ECU. (all in one breath!)

I have read in the past that on 6th generation bikes disabling this "flapper" eases the throttle transition, it seems to help.

 

over here on the east coast we're behind times..................hehe

 

Yo Troy; I live on the east coast so speak for yourself. I believe its dyno short for Dynamometer!!

 

I was hoping for useful input, in the meantime I'll work on my spelling.:wink:

 

If you're going to do a full map on the dyno, then you can remove it. At the end of the day I doubt you're going to see much gain. But you'll get your money's worth from the mapping.

Better yet, get it mapped w/ and then w/o flappers; you can tell us which one is better or worse. Not being facetious....if you have the money or can convince the tuner to do it for just a little extra $$, then definitely go for it. I'm sure some hard evidence one way or the other would be very useful.

Removing it on an otherwise stock bike is pointless w/o remapping.

 

I tried it for shits and giggles and I too found that the bike was less responsive so I hooked it back up. That was an ass dyno evaluation and the issue is at low throttle openings so you may or may not see a difference on the dyno sheets. It is more of a rideability thing.

( I hope rideability is a word or I will pay)

Let us know what you see on the runs.

 

I just had my 01 mapped/dyno and left everything else alone. The tech was looking for optimum fuel/air mix across all gears and throttle positions more than horse power. With a PCIII and Jardine slip on it went from 95 to 102 hp at wheel and 52 to 58 ft lbs of torque. It runs like a raped ape. Hit the throttle no matter what gear and BOOM! She's gone.

 

What PCIII Map were you running? Did you tweak it while on the Dyno or were you running an existing map?

 

Eddie,

I disconnected my Flapper earlier in the week for the first time. What I noticed is that my roll in and throttle is much smoother than it use to be. It used to be a little choppy no matter how smooth I was with the throttle. There was a place you'd get to with the throttle where the revs would just jump. With the flapper disconnected there is no jumping around on revs. It is a smooth progression as I twist the throttle.

I attributed this change to the flapper not opening up at intervals and bringing in more air making things jump around. I'm not sure if that is what is really happening, but it sure seems easier to ride now to me.

 

jethro911, "rideability" is definately a word in my book!!

I will keep all posted, it will be a while, seeing we woke up to another 6" of snow today.

 

PARedVFRrider- The tech at Marietta Motosports did the mapping while running on dyno. I am VERY happy with the results.