air box mod?

[wildchildbmx6]

i keep hearing about a stock air box mod. what is it?

[Tybalt]

i keep hearing about a stock air box mod. what is it?

on the genI 99-07 you remove the flapper valve inside the airbox and the PAIR valve

[Busa1]

I just had it done to my bike.....along with a power commander....and the results are incredible. It feels like a new....faster Busa :oh yeah:

Duane, thanks for hooking me up with Mickey.....the guy is good :smoke:

[Quasar]

i keep hearing about a stock air box mod. what is it?

The "Small Box Mod" involves removing the flapper, then cutting out the inner deck (see attached photos). Some elect to leave the vacuum module in the bottom of the air box while others (myself included) elect to remove the vacuum module. I cut a circular piece from the flapper I removed and used it to block the hole where the vacuum module had been (why waste the flapper's plastic, ay?). I used 1 hour silicon to hold the plastic that blocked the vacuum module hole.

You also need to either install block off plates or use a marble to block off the larger hose that runs to the Pair Valve, then reinstall the blocked hose (the marble is only used if you aren't removing the Pair Valve, otherwise, block off plates are used). I completely removed my Pair Valve and made my own aluminum block off plates. It's not a huge weight savings, but I figure, why tote it around if it's not being used.

[Quasar]

Incidentally, while you have the air box off to perform the Small Box Mod, it pays to install Nick Smith's aftermarket RAM-Air seals and also install a K&N or BMC air filter. I've been using the K&N air filter on my 99 Hayabusa and 01 GSXR1000 and they have paid for themselves many times over in their many years of use.

In the summertime, due to the high bug content while riding in the mountains, I typically clean my K&N air filter every 2,000 miles. You'd be surprised out much road grit and bug carcasses are picked up in just 2,000 miles. Remember, optimal fueling requires peak airflow, so keep that air filer clean. Air filter companies tell you to keep them clean, but they fail to instill the urgency in doing so in order to maintain optimal performance and crisp throttle response. :thumbs up:

Also in the picture is a shredded 16-tooth steel sprocket from a stock Hayabusa engine. My customer allowed their EK drive chain to stretch too far without readjusting as required, so the moment the drive chain finally jumped, it acted like a high-speed multi-impact hammer and ate most of the teeth. Lesson learned the hard way, but it could have been worse had it also broke the chain and slammed through the engine cases, and needless to say, this has happened.

[southerncomfort81]

wow i might have to do that mod soon

[rafybusa]

you feel any difference in a stock hayabusa?

[wildchildbmx6]

ive been advised that if doing this mod you should be running a power commander and some exhaust.

[Busa1]

ive been advised that if doing this mod you should be running a power commander and some exhaust.

This is true :oh yeah:

[wildchildbmx6]

how does this mod affect cold start and idle? and streetability?

[Quasar]

ive been advised that if doing this mod you should be running a power commander and some exhaust.

You don't "need" a Power Commander and exhaust system to perform the Small Box Mod, but it can certainly provide some benefits, as even a completely stock Hayabusa engine can benefit from the install of a Power Commander.

[BusaGTP]

For the small air box mod you don't need a power commander and exhaust but it will help if you decide to do other things like a big air box mod or if you decide to roll with all short stacks. I had the airbox mod and flat stacks on the outside and short stacks in the middle and the performance was amazing considering that the mod doesn't cost you anything, but when i was running 140 - 170mph every time i would get off the throttle to slow down i would get a backfire, but only running at high speeds then getting off the throttle.

[Cali Badazz !!!]

i love when you post like this Quasar. it shows how much attention to detail you pay. your pics always make sense of what you are saying.:thumbs up:

[Quasar]

i love when you post like this Quasar. it shows how much attention to detail you pay. your pics always make sense of what you are saying.

Having taught Associate level Electronic Engineering for many years, and having had to make corrections to a number of textbooks in various chapters, then demonstrate and prove to my engineering students why the textbook was incorrect, I have an immense appreciation for highly detailed, wonderfully articulated explanations with mathematical examples, diagrams, etc...

I strive for perfection in all of my explanations and examples and these days, I take as many pictures as I can while working on various assemblies to assist others down the road. :cheers:

[FreaK]

Having taught Associate level Electronic Engineering for many years, and having had to make corrections to a number of textbooks in various chapters, then demonstrate and prove to my engineering students why the textbook was incorrect, I have an immense appreciation for highly detailed, wonderfully articulated explanations with mathematical examples, diagrams, etc...

I strive for perfection in all of my explanations and examples and these days, I take as many pictures as I can while working on various assemblies to assist others down the road. :cheers:

Sometimes I just want to cuddle with you!:oh yeah:

[wildchildbmx6]

how does this mod affect low speed drivability, idle, and cold starting? would this mod cause backfiring?

[Quasar]

Sometimes I just want to cuddle with you!:oh yeah:

:rofl:

[Quasar]

how does this mod affect low speed drivability, idle, and cold starting? would this mod cause backfiring?

The Small Box Mod doesn't alter the engine's characteristics enough to cause any problems, but it does eliminate potential problems that could otherwise occur down the road if the flapper fails to open or begins working erratically due to vacuum or vacuum module related issues.

Any backfiring on engine deceleration (especially prevelant between 4,000 through 5,000 RPM) is typically a result of the install of an aftermarket performance exhaust system. Since these performance mufflers are straight-through types with no baffles, the backfiring (which is actually always present, but too quiet to hear due to the OEM mufflers) isn't suppressed, so it's easily heard.

The solution: Removal of the Pair Valve and the install of block off plates or the install of a marble in the hose that feeds the Pair Valve. This eliminates the fresh air being drawn directly into the headers thereby eliminating the backfiring.

[071300r]

I have done this mod with only slip ons and a k-n air filter and have noticed a big difference and have no popping on decel or accelration at all. my bike is a 2007 I bought it new in july it now has 17,500 on the clock still going strong with no problems.

[probe]

hi i have just done the mod on my k5 and it is like a diffrence bike

:thumbs up:

[05busablu]

I would imagine there isnt any dif between gen1 or gen2 in this mod?

[Kamdon]

very good thread.

[05busablu]

so is a more air velocity mod ....loose torque and gain topend hp?

[jzbusa]

It just feels better everywhere, its worth doing just for the noise alone !

[kml666]

Sure like to see before and after dyno charts.

just saying.


cheers
ken

[05busablu]

yeah that would put all this to rest, if the was a dyno within 100 miles id do it

[jstdoit95]

alright....Im going to ask what is probably a horribly dumb question...but keep in mind...Im extremely sleep deprived right now have but in 18 hours in the last 36 working on my bike.....since I have it all ripped apart, decided it would be a good time for plugs, since its a good time for plugs, would be a good time for the airbox mod....have the box gutted and the bottom recovered....my question comes in the whole marble in the hose thing that is previously mentioned....the hose that goes to the valve that is removed from the box could not possible fit a marble into it...the only hose I see that could fit a marble is the one that plugs into the box at the right rear....there is already a plug in the hole on the left rear of the box.....so....do I plug the hose that the I unplugged from the now deceased valve, or do I plug the one towards the right rear....or...both...sorry if this is a stupid question, Im just tired of thinking and need to wrap this up since Im moving in a couple of days.....Thank you very much, pics and video of the new exhaust and mods will be posted upon completion.....cuz everyone is anxiously waiting Im sure.

thanks again

[kml666]

Plug right rear hose.
yer done.

cheers
ken

[jstdoit95]

thanks, what about the hose that went to the vac module...does that need to be plugged as well? I wish I had my bike in front of me...at least I though there was a small hose going to it....maybe Im dreaming hahahaa...anyway....thanks....cant wait to be done.....all I have left is finishing that up...installing my power commander and then letting it run to burn crap off/check fluid levels and button her back up....then load it in the moving van haha....thanks again.