removing Air Funnels

I have also seen pictures from other members with the air funnels in the air cleaner housing removed what does this do? and does anyone know if this is a good idea?

Also i have talked with other members about this but when you remove the Snorkel the flapper is there too should i remove it or prop it open????????
What does this do for the bike????
Will it effect the way the bike starts or runs cold or hot.

 

I removed both the flapper and the snorkel, now I have more airbox noise....not sure if I gained any performance....don't think I lost any though

 

what do you mean by air funnels?
the plastic stacks in the air box?

modding air box is to get more air in it someone posted .5 - 2 hp gain by removing the flapper and snorkle.

you can also open it up a bit as well

 

there is a link with dyno charts involved if u search air box mod, from what i have seen i doesnt look like its worth the hassle to remove the snorkel i think the max gain was 1.1 hp. but for the most part across the rpm range it was less than 1 hp and 1ftlb
i dont know if there would be any starting or drivability to removing the snorkel i guess there is only one way to find out

 

removing the snorkel only takes about 2 minutes...lift tank, pull out, drop tank...done

OP was referring to the velocity stacks below the air filter....

 

Don't remove those stacks or you'll lose power.....

 

The velocity stacks can also be used to "tune" the power of your machine. The longer the stacks...more low to midrange. The shorter the stacks....more top end. Like S-man says, do not remove the stacks. Although some folks here have done it, DON'T do it.

I have an experiment planned for next spring when I will be doing the final tune on my machine. I have purchased a second set of stacks and will be trying four of each length, long or short, just to see what the actual difference is. I will also be doing two separate tunes, one with pump gas, and one with VP U4.2, hopefully I can afford enough dyno time to compare stacks during this test also.

 

Dat's right....motoGP bikes ( and possibly a few streetbikes) have setups that telescope the stacks in and out depending upon rpms. how cool is THAT ??

Formula 1 cars were first to use it.

 

that is awesome tech, servo controlled variable intakes. the best of everything. can be found on the 2009 R1 and i believe the RSV4.

 

Answer: Waaaay cool heeeheeee.

Now we have paddle shift VFRs too, way cool? Well the tech is.

 

was just looking at those stacks....couldnt we run a pair of long and a pair of short for a more balanced power band?

 

Honda did that on 4th gen bikes, and if it worked on yours, you'd have it.

 

Thanks S-man and NCB for clearing up WHY the velocity stacks should NOT be removed.

BZ

 

I have a 6th gen and was thinking if you remove the snorkle and flapper. Also take out the signalling indicators and set up fresh air ducting into the airbox area would that make a dirrerence. We did it years ago to 91 model VFR with moriworki exhausts and different jets for 750 supersport racing and it work good

 

I've been contemplating this for months and just haven't settled on a way to do it correctly yet. I think this could be a great mod for the VFR to get some more ponies out of the engine without going inside. Obviously integrated signals into the mirrors would take care of the legal aspect of having the signals, but the problem is venting the air correctly to the box. The real issue is the lack of space given to us to work with since the air box draws air from between the top of the frame and the bottom of the tank. This is a narrow 1" channel at best. There is also some space between the bottom of the frame and the engine but that requires some sharp bends in the ducting and causes a loss of velocity in the air glowing to the box, thus negating the ram air effect of the box. The lack of space to work with is what makes it so difficult. If this is done incorrectly you end up causing negative air pressure inside the box instead of positive and you rob the engine of air and power instead of increasing it.

 

Oh... and to stay on topic... the others are correct. Removing the velocity stacks will have negative impacts on performance. The snorkel and flapper are there to keep sound down for the rider. Removing them adds a small amount of HP depending on the RPMs, up to 2 hp as confirmed by dyno runs posted on here somewhere. Personally I would remove the flapper so that you don't have anything there to fall out while riding. It should not affect starting nor temperature of the engine.

 

They are doing this on the new 7th gen as well, reference: .... damnit i cant find them now, two or three month's ago motorcyclist or cycle world, they went into the engine tuning specifics.

 

This is a question for all who have removed the flapper and the 'actuator'? or 'valve'? that opens the flap. (#8 in the airbox diagram thinger) What did you do with the hose controlling the 'actuator' or 'valve'? Cap it off? Leave it open?

 

on the 6th gen the stacks are 2 different sizes already.

 

cap off the vacum line going to the flapper