6th gen Velocity Stacks

I just recieved my BMC filter today, so I decided to also do the other popular mods pertaining to the air box: flapper mod and desnorkel. While installing the filter it became aparent to me that with the added depth of the new filter there really isnt that much room for the velocity stacks to do thier job. The bmc practically rests on top of them. Mabey this is why the KN's filter area is so much less, (as to not disrupt the velocity stacks)? Well I thought about shortening them to give them some more room, but it seemed like way too much effort, and I am a little reluctant to destroy my perfectly functioning stock velocity stacks on a whim. So, just for sh@@s and giggles, I decided to take them out and see how she performed with out them. I was expecting a loss in bottom end and hopefully a gain up top if I was lucky...
To my amazement she performed flawlessly! It really didnt feel like there was a loss anywhere in the powerband. I mean from idle all the way to redline. It actually felt in ,my opinion, stronger everywhere. But the sound was amazing. Wide open I can't even hear my gutted cans any more.
I have only put about 10 miles on her since, so I'll be sure to keep you guys posted. But, so far, no issues. I would deffinetly recomend doing the
BMC filter, desnorkel, flapper mod, and taking out the velocity stacks all at once. At the very least its worth trying as nothing I did today was irreversable. Let me get some feed back...

 

Well, I agree that removing the snorkel and flapper is worthwhile, and produces a sensational induction roar, (actually I think they are only there to cut down on noise levels) but I would have thought that removing the velocity stacks would lead to a loss in torque somewhere in the rev range.
Usually the idea is to tune the length of the induction tract to resonate at a particular RPM range to boost the torque there, the longer the tract the lower the RPM.
The VFR is odd because the front and rear ones are a different length, so obviously its a compromise. Why they did that is a mystery. Some people have fitted 4 short ones and others have fitted 4 long ones, and they all reckon its an improvement!
You may find you get some fuel blowback into the airbox without them, but it will be interesting to see how it goes in the longer term.
Did you notice there are 2 small cutouts on the bottom of the velocity stacks on one side?
I have no idea what they are for. Does anyone know? If you put the stacks on 180 degrees out, the notches will be in the wrong place.
Whether it would make any difference, I have no idea.
How did you hold the airbox on? just use shorter screws?

 

I Just Used The Same Screws And Added A Couple Of Washers...
As A Side Note Today On My Way Home From Work On An Empty Stretch I Brought It Up To About 7 Grand And Opened It Up. The Front End Came Off The Ground Faster And Higher Than Ever Before. I Know Most Of These Mods Psych You Into Thinking They Worked, You Know More Noise=more Power, But I Think Power Wheelies Are About The Best Indicator Next To A Dyno And Were Not Exactly Over Run With Those Down Here In The Keys...

 

Anything else you have to do when you remove the flapper???
I have remover the snorkle from mine already.
as far as stacks go I set mine so they are all at the same height when I put them back on but never really looked at them when I took them off so I have no clue if they are installed right. anyone anyone ???

 

How Exactly Did You Set The Height Of The Velocity Stacks? 2 Are Long And 2 Are Short. I Dont See How You Could Change That Unless You Have 2 From One Bike And 2 From Another... Anyways The Flapper Mod: I Just Took The Whole Actuator Out And Plugged The The Vacuum Line.

Another Thought If The Stacks Are About 1mm Thick And Lining The Bore Of The Throttle Bodies Im Thinking That Essentially They Are Taking 36mm Throttle Bodies And Making Them Flow More Like 34mm Throttle Bodies.

At This Point Im Seeing Them As A Restriction...

 

I think I have two long in the back and two short in the front and when set like that they are the same hieght, if reversed it seems the long in the front seem taller.
so take flapper off and block vacum line and leave the space open?
how about pair mod valve - is that what the flapper is for?

 

The Flapper Itself Is Still In There. When Its Disconnected Gravity Just Holds It In Place Tucked Away. I Just Took The Actuator Out. All The Space Is Left Open. As For The Pair That's Something Completely Different. I Believe Its Emissions Equipment That Pumps Air Into The Exhaust To Help Burn The Rest Of The Fuel.

 

holy shit candy. I cannot even read your posts with every word starting with a capital letter. Might want to fix that next time

either way, good luck with this and keep us updated.

 

Lol my bad about the caps. Well I've finally put some real miles on her since the mods. Today my buddy an me took the nighthawk and interceptor from key west all the way to big pine key and back, stopping in middle torch key on the way up to try out some of the twisties. It was a lot of fun. Both bikes ran great and it was another beautiful sunny day down here. Now that I'm feeling a little more comfortable with the velocity stacks being gone and I'm sure that they're not helping anything by being in there I'm thinking about breaking out the dremel and smoothing out the entrances where the stacks used to be a little. You know nothing major just rounding them out a little. I know I'm not pushing out huge numbers yet, but I'm sure all these little things are going to add up when I do eventually get her tuned on the dyno...