DIY: Performance Airbox mod

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 12:00 am

Disclaimer: I will not be held responsible for any problems created from this mod. Professional tuning is required!

I don't recommend this mod to anyone who doesn't understand the tuning of these scooters

This is to go along with an aftermarket exhaust, not to be used with stock exhaust.

Tools needed:
Philips screwdriver #2
Drill and 1/2in drill bit or Dremel
Pliers

Step 1:
Remove the airbox cover via the 7 screws around the border

Step 2:
Use the drill or dremel to remove the material inside of the drain

Step 3:
use the pliers to break off the plastic inside over the drain (not necessary)

Step 4:
Remove the snorkel from the back of the air filter

Step 5:
Reinstall the cover, careful not to over tighten the screws.

Step 6:
Tune accordingly (I strongly recommend having your shop do this)

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 6:53 am

Nobody even chimed in to make fun of my typo?

Cheshire · Post by **Cheshire** » Wed May 27, 2009 7:40 am

This is for increased airflow into engine? What kind of tuning would be needed...jetting, anything else?

Nice mod!

How's it working for ya?

Edit: Either I'm just off today, or I'm tired. I couldn't find the typo.

Bad me!

Kaos · Post by **Kaos** » Wed May 27, 2009 1:37 pm

Nice writeup Scootertrash! I need to get on this as soon as I get off my lazy butt and order more jets.

Lostmycage · Post by **Lostmycage** » Wed May 27, 2009 2:06 pm

Nice writeup ST! I've done something similar with the Blur (it's a lot easier since there's no snorkel). Not quite as dramatic, but this does open up the intake. It's a good combo to do with an exhaust (and carb tuning).

Kaos!?! Still!?! Get to it man! Unless you're forcing yourself to have a reason to get the BB kit (you know, cause of the hole in your stock piston

).

broke · Post by **broke** » Wed May 27, 2009 2:31 pm

What exactly is the "snorkel"?

Is that the tube extension connected to the plastic air filter gasket / frame? Isn't that needed to make a seal with the intake tube running to the engine?

Thanks for posting the pics and the tech tip ST.

Lostmycage · Post by **Lostmycage** » Wed May 27, 2009 2:40 pm

The small snorkel is the one he's talking about removing. The large snorkel is the one that goes to the engine.

The small snorkel increases the resistance of air coming in. With it gone, air can get sucked in much easier by the engine.

I'm a little slow this morning... what typo?

Cheshire · Post by **Cheshire** » Wed May 27, 2009 2:55 pm

I ask about airflow because I thought that's what the mod on the muffler side was for. Isn't that the air intake? What's this side do? I'm confused. Teach the newbie masses!

Kaos · Post by **Kaos** » Wed May 27, 2009 3:36 pm

Lostmycage wrote:Nice writeup ST! I've done something similar with the Blur (it's a lot easier since there's no snorkel). Not quite as dramatic, but this does open up the intake. It's a good combo to do with an exhaust (and carb tuning).

Kaos!?! Still!?! Get to it man! Unless you're forcing yourself to have a reason to get the BB kit (you know, cause of the hole in your stock piston ).

Yeah, seriously. I'm kinda pushing my luck with running lean.... Though I've nearly got enough spare cash to get my very own BB kit.

Lostmycage · Post by **Lostmycage** » Wed May 27, 2009 3:45 pm

I'd save up and get a few jets with that kit

Cheshire, I'm not really sure what you're asking... can I get you to rephrase that a little?

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 4:34 pm

Cheshire wrote:I ask about airflow because I thought that's what the mod on the muffler side was for. Isn't that the air intake? What's this side do? I'm confused. Teach the newbie masses!

The muffler increases air going out which does nothing if you don't have more coming in, that is what this mod is for

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 4:36 pm

Lostmycage wrote:The small snorkel is the one he's talking about removing. The large snorkel is the one that goes to the engine.

The small snorkel increases the resistance of air coming in. With it gone, air can get sucked in much easier by the engine.

I'm a little slow this morning... what typo?

The typo was in the title but I fixed it

broke · Post by **broke** » Wed May 27, 2009 5:51 pm

Lostmycage wrote:The small snorkel is the one he's talking about removing. The large snorkel is the one that goes to the engine.

The small snorkel increases the resistance of air coming in. With it gone, air can get sucked in much easier by the engine.

So, where exactly do you "remove" that small snorkel? (or is it already removed in ST's photo?)

Do you have to dremel it off, or is it a bolt-on?

Is it removed from the air-filter gasket / frame? or, from the back housing of the airbox?

Is my photo attached below accurate? MOST air into the air box enters from the small snorkel, then it is redirected and forced through the filter, then it exits a large snorkel out the back of the air-box (not shown in any of those pics)?

So, ST's mod does 2 things:

1: he allows more air into the front of the airbox by opening up the "drain" hole.

2: he allows more air into the front of the airbox by removing a length of tube (aka "small snorkel").

Sorry, fluid dynamics was a long time ago. I understand diameter of a pipe affects air resistance, by why does a small LENGTH of a pipe increase air resistance? It seems like the small snorkel is the same opening size on both ends... and it is a pretty short length of tube... why bother removing it?

Lostmycage · Post by **Lostmycage** » Wed May 27, 2009 6:46 pm

Yep, he's already removed it. That tube is on the unfiltered side. The tube that goes to the barb is behind the filter in that photo.

The reason it restricts airflow so much is that it's corrugated. Turbulent air gets all jumbled up in the snorkel. Take a peek under your Buddy's skirt and it'll make sense.

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 7:02 pm

Lostmycage wrote:Yep, he's already removed it. That tube is on the unfiltered side. The tube that goes to the barb is behind the filter in that photo.

The reason it restricts airflow so much is that it's corrugated. Turbulent air gets all jumbled up in the snorkel. Take a peek under your Buddy's skirt and it'll make sense.

It's also facing the gas tank, not out in the open where it can breath

KRUSTYburger · Post by **KRUSTYburger** » Wed May 27, 2009 7:09 pm

So I guess if you do this mod then all need to do is up jet (a lot)? Or is there other "tuning" involved?

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 7:12 pm

KRUSTYburger wrote:So I guess if you do this mod then all need to do is up jet (a lot)? Or is there other "tuning" involved?

Main Jet + some air mixture tuning to get the idle right

KRUSTYburger · Post by **KRUSTYburger** » Wed May 27, 2009 7:14 pm

Idle is simple enough, could you give me a brief description of how one would go about adjusting the air mixture?

ScooterTrash · Post by **ScooterTrash** » Wed May 27, 2009 7:16 pm

KRUSTYburger wrote:Idle is simple enough, could you give me a brief description of how one would go about adjusting the air mixture?

PM me, I don't want to tell everyone how to mess with the fuel mix

Kaos · Post by **Kaos** » Wed May 27, 2009 8:03 pm

ScooterTrash wrote:
KRUSTYburger wrote:Idle is simple enough, could you give me a brief description of how one would go about adjusting the air mixture?
PM me, I don't want to tell everyone how to mess with the fuel mix

Good call on that.

broke · Post by **broke** » Wed May 27, 2009 8:19 pm

Lostmycage wrote:Take a peek under your Buddy's skirt and it'll make sense.

It's a kilt, and I did... my Buddy is hung like a horse!

sorry... crude humor is my specialty

Thanks for the clarification.

ScooterTrash · Post by **ScooterTrash** » Thu May 28, 2009 12:35 am

broke wrote:
Lostmycage wrote:Take a peek under your Buddy's skirt and it'll make sense.
It's a kilt, and I did... my Buddy is hung like a horse!

sorry... crude humor is my specialty

Thanks for the clarification.

If you pull the seat bucket you will see why it's restrictive

charltons · Post by **charltons** » Thu May 28, 2009 12:40 am

I'm wondering, and maybe it's my ignorance of airflow/fuel mixture dynamics, but couldn't a large hole w/ a screen, or several small holes be drilled in the housing covering the filter?

Kaos · Post by **Kaos** » Thu May 28, 2009 12:42 am

charltons wrote:I'm wondering, and maybe it's my ignorance of airflow/fuel mixture dynamics, but couldn't a large hole w/ a screen, or several small holes be drilled in the housing covering the filter?

Absolutely. They even make small air filter 'plugs' that you can put in those holes for exactly that useage.

ScooterTrash · Post by **ScooterTrash** » Thu May 28, 2009 12:52 am

charltons wrote:I'm wondering, and maybe it's my ignorance of airflow/fuel mixture dynamics, but couldn't a large hole w/ a screen, or several small holes be drilled in the housing covering the filter?

Yes, this just looks stock while giving a good performance boost

charltons · Post by **charltons** » Thu May 28, 2009 1:04 am

Kaos wrote:
charltons wrote:I'm wondering, and maybe it's my ignorance of airflow/fuel mixture dynamics, but couldn't a large hole w/ a screen, or several small holes be drilled in the housing covering the filter?
Absolutely. They even make small air filter 'plugs' that you can put in those holes for exactly that useage.

who sells these? thanks.

Taz · Post by **Taz** » Thu May 28, 2009 5:42 am

Keep in mind that many of these mods can increase the chance of rain finding its way into the intake and ultimately into the motor. Water is not compressible and will cause a hydraulic lock typically bending the connecting rod.

Keep in mind that even if you DON'T ride in the rain, you need to make sure when washing your scooter you don't get any water in the intake. If you even remotely think you might have, DON'T crank the motor over. Pull off the intake and check. If you can't tell for sure then, remove the spark plug and turn the motor over by hand with the kick starter.

If you use the little filter plugs, make sure you but them in a location that is less likely to induce the water into the intake as well. Keep in mind that you also need to pay closer attention to cleaning/replacing your air filter as well with these types of mods. That "convoluted" intake path also makes it harder for dirt to find its way in.

Lastly you will often find the scooter can be much noisier as well. While some of you mike like the growl, I tend to find CVT type motors more of a boring drone as they are stuck at about 5,000 rpm (just a guess for sa stock Buddy as I haven't put a tach on one yet) or so until they finally wind out a bit. I personally like keeping my scooter and motorcycles pretty quiet so I can ride faster without attracting undue attention. YMMV of course. I don't mind a little audible feedback from my ride though in general I just want it to telegraph my evil intentions to a police officer a mile away...

ScooterTrash · Post by **ScooterTrash** » Thu May 28, 2009 6:25 am

Taz wrote:Keep in mind that many of these mods can increase the chance of rain finding its way into the intake and ultimately into the motor. Water is not compressible and will cause a hydraulic lock typically bending the connecting rod.

Keep in mind that even if you DON'T ride in the rain, you need to make sure when washing your scooter you don't get any water in the intake. If you even remotely think you might have, DON'T crank the motor over. Pull off the intake and check. If you can't tell for sure then, remove the spark plug and turn the motor over by hand with the kick starter.

If you use the little filter plugs, make sure you but them in a location that is less likely to induce the water into the intake as well. Keep in mind that you also need to pay closer attention to cleaning/replacing your air filter as well with these types of mods. That "convoluted" intake path also makes it harder for dirt to find its way in.

Lastly you will often find the scooter can be much noisier as well. While some of you mike like the growl, I tend to find CVT type motors more of a boring drone as they are stuck at about 5,000 rpm (just a guess for sa stock Buddy as I haven't put a tach on one yet) or so until they finally wind out a bit. I personally like keeping my scooter and motorcycles pretty quiet so I can ride faster without attracting undue attention. YMMV of course. I don't mind a little audible feedback from my ride though in general I just want it to telegraph my evil intentions to a police officer a mile away...

The other reason I did it this way was actually to get more air while still keeping water out. I have checked the airbox after rides in heavy rain to see where the water is getting and the snorkel side is always dry and nothing comes up the drain hole either.

Also, this mod doesn't create any extra noticeable noise from the airbox.

Your comment is the exact reason I came up with this VS. getting a uni filter

Taz · Post by **Taz** » Fri May 29, 2009 6:24 am

Glad to see you took this into account. Water ingestion is not a pretty sight! Most people never think of these things when doing a lot of these mods. They mod first and then learn about the unintended consequences later.

Most people would be wise to really understand the effects of their intended mods as well as potential unwanted side-effects. For example often people just copy the jetting specs of another scoot. Very few people here understand the effects of altitude, temps, mods, etc with respect to appropriate jetting. Nor do they understand how easy it is to seize a 2-stroke motor. They don't understand that what works in another scoot with similar mods to yours MAY NOT WORK the same in yours due to the environmental variables as well as equipment variations.

People really need to be cautious about what mods they do. They should also plan out what they ultimately want to accomplish and perform their mods in a systematic fashion rather than piecemeal which can often result in reduced performance instead of better...

Kaos · Post by **Kaos** » Fri May 29, 2009 12:59 pm

Taz wrote:Glad to see you took this into account. Water ingestion is not a pretty sight! Most people never think of these things when doing a lot of these mods. They mod first and then learn about the unintended consequences later.

Most people would be wise to really understand the effects of their intended mods as well as potential unwanted side-effects. For example often people just copy the jetting specs of another scoot. Very few people here understand the effects of altitude, temps, mods, etc with respect to appropriate jetting. Nor do they understand how easy it is to seize a 2-stroke motor. They don't understand that what works in another scoot with similar mods to yours MAY NOT WORK the same in yours due to the environmental variables as well as equipment variations.

People really need to be cautious about what mods they do. They should also plan out what they ultimately want to accomplish and perform their mods in a systematic fashion rather than piecemeal which can often result in reduced performance instead of better...

Thats great advice for any modder to follow. Know what your end goal is before you ever start. Some mods will hinder other mods, and you need to know which is which before you ever start.

Like Taz said, you can come out with a very poorly performing bike if you do things haphazardly, or a screaming fast bike if you do things systematicly.

ScooterTrash · Post by **ScooterTrash** » Fri May 29, 2009 2:40 pm

Kaos wrote:
Taz wrote:Glad to see you took this into account. Water ingestion is not a pretty sight! Most people never think of these things when doing a lot of these mods. They mod first and then learn about the unintended consequences later.

Most people would be wise to really understand the effects of their intended mods as well as potential unwanted side-effects. For example often people just copy the jetting specs of another scoot. Very few people here understand the effects of altitude, temps, mods, etc with respect to appropriate jetting. Nor do they understand how easy it is to seize a 2-stroke motor. They don't understand that what works in another scoot with similar mods to yours MAY NOT WORK the same in yours due to the environmental variables as well as equipment variations.

People really need to be cautious about what mods they do. They should also plan out what they ultimately want to accomplish and perform their mods in a systematic fashion rather than piecemeal which can often result in reduced performance instead of better...
Thats great advice for any modder to follow. Know what your end goal is before you ever start. Some mods will hinder other mods, and you need to know which is which before you ever start.

Like Taz said, you can come out with a very poorly performing bike if you do things haphazardly, or a screaming fast bike if you do things systematicly.

What about running lean if your lazy?

Kaos · Post by **Kaos** » Fri May 29, 2009 2:44 pm

ScooterTrash wrote:
Kaos wrote:
Taz wrote:Glad to see you took this into account. Water ingestion is not a pretty sight! Most people never think of these things when doing a lot of these mods. They mod first and then learn about the unintended consequences later.

Most people would be wise to really understand the effects of their intended mods as well as potential unwanted side-effects. For example often people just copy the jetting specs of another scoot. Very few people here understand the effects of altitude, temps, mods, etc with respect to appropriate jetting. Nor do they understand how easy it is to seize a 2-stroke motor. They don't understand that what works in another scoot with similar mods to yours MAY NOT WORK the same in yours due to the environmental variables as well as equipment variations.

People really need to be cautious about what mods they do. They should also plan out what they ultimately want to accomplish and perform their mods in a systematic fashion rather than piecemeal which can often result in reduced performance instead of better...
Thats great advice for any modder to follow. Know what your end goal is before you ever start. Some mods will hinder other mods, and you need to know which is which before you ever start.

Like Taz said, you can come out with a very poorly performing bike if you do things haphazardly, or a screaming fast bike if you do things systematicly.
What about running lean if your lazy?

quiet you, i ordered jets yesterday...

ScooterTrash · Post by **ScooterTrash** » Fri May 29, 2009 2:57 pm

Kaos wrote:
ScooterTrash wrote:
Kaos wrote: Thats great advice for any modder to follow. Know what your end goal is before you ever start. Some mods will hinder other mods, and you need to know which is which before you ever start.

Like Taz said, you can come out with a very poorly performing bike if you do things haphazardly, or a screaming fast bike if you do things systematicly.
What about running lean if your lazy?
quiet you, i ordered jets yesterday...

I named no one

Lostmycage · Post by **Lostmycage** » Fri May 29, 2009 3:11 pm

Poor Kaos. He's gonna loose about 3mph when he rejets. Turns out that burning piston is one of the best fuel additives for horsepower. On the plus side, he's probably displacing about 127cc's by this point, as much as he rides (and as long as he's been lean).

Taz · Post by **Taz** » Fri May 29, 2009 3:51 pm

Lean is good when it comes to ground beef...not so good for motors.

I'll never forget how a Cosworth piston looked in one of my race bikes when the nitrous worked fine but the additional fuel jet was clogged by a piece of the fuel filter. Can you say lean?

You know a 2lb bottle of nitrous would last a LONG time on a Buddy...

Lostmycage · Post by **Lostmycage** » Fri May 29, 2009 3:56 pm

It'd probably last longer than the piston would.

Kaos · Post by **Kaos** » Fri May 29, 2009 4:20 pm

Taz wrote:Lean is good when it comes to ground beef...not so good for motors.

I'll never forget how a Cosworth piston looked in one of my race bikes when the nitrous worked fine but the additional fuel jet was clogged by a piece of the fuel filter. Can you say lean?

You know a 2lb bottle of nitrous would last a LONG time on a Buddy...

Yikes! I've unfortunately done the same thing in a 340 small block, the 200HP shot of nitrous worked great, the wet-jet solenoid had failed and didn't open.... Well it was an excuse to put better pistons in it.....

I've been real tempted to try a small shot of NoS on my Buddy, but I don't have anything small enough that I wouldn't just blow the crank out the back end....

Lostmycage · Post by **Lostmycage** » Fri May 29, 2009 4:56 pm

On the positive side, if you were to spray it, you'll be really glad you've got a horizontal engine instead of a vertical when the piston shoots out.

Kaos · Post by **Kaos** » Fri May 29, 2009 5:04 pm

Lostmycage wrote:On the positive side, if you were to spray it, you'll be really glad you've got a horizontal engine instead of a vertical when the piston shoots out.

I dunno, no mater which way it goes it'll take out a wheel. With vertical at least there's a 50% chance it's headed towards the ground...

Lostmycage · Post by **Lostmycage** » Fri May 29, 2009 5:07 pm

It's that other 50% I was referring to.

Kaos · Post by **Kaos** » Fri May 29, 2009 5:08 pm

Lostmycage wrote:It's that other 50% I was referring to.

Well, yes I suppose there's that too...

Cheshire · Post by **Cheshire** » Sat May 30, 2009 3:37 am

I finally figured out my confusion. I was confusing yours and djelliot's mods. He's got the UNI filter, right? I thought this was in addition to a UNI filter!
Makes more sense now.

Kaos's link to the VooDoo Buddy site isn't working last I tried. I can't keep straight who's done what anymore.

Kaos · Post by **Kaos** » Sat May 30, 2009 3:45 am

Cheshire wrote:I finally figured out my confusion. I was confusing yours and djelliot's mods. He's got the UNI filter, right? I thought this was in addition to a UNI filter!
Makes more sense now.

Kaos's link to the VooDoo Buddy site isn't working last I tried. I can't keep straight who's done what anymore.

Yeah, I accidentally let the domain expire, It'll be back ASAP.

ScooterTrash · Post by **ScooterTrash** » Sat May 30, 2009 6:21 am

Cheshire wrote:I finally figured out my confusion. I was confusing yours and djelliot's mods. He's got the UNI filter, right? I thought this was in addition to a UNI filter!
Makes more sense now.

Kaos's link to the VooDoo Buddy site isn't working last I tried. I can't keep straight who's done what anymore.

I'm not on there anyway

I do have a thread in the Scooter Gallery though

Vic · Post by **Vic** » Sat May 30, 2009 5:32 pm

broke wrote:
Lostmycage wrote: Sorry, fluid dynamics was a long time ago. I understand diameter of a pipe affects air resistance, by why does a small LENGTH of a pipe increase air resistance? It seems like the small snorkel is the same opening size on both ends... and it is a pretty short length of tube... why bother removing it?
Oh, I know the answer to this!

The air has to, in effect, bounce around the longer tube for longer, this turbulence increases the resistance.

Try taking a drinking straw and cut it off really short and breathe through it for a while, then do the same thing with a long straw of the same diameter.

You will become air hungry much faster, and work harder for what you do get, with the longer straw because of this.

-v

Lostmycage · Post by **Lostmycage** » Sat May 30, 2009 8:14 pm

Vic wrote:Oops! I quoted the wrong person. Sorry LMC, you're so understanding and keen!
-v

It's cool, that's how I roll.

someotherdude wrote:Yeah! Awesome!

Stop it you're making me blush!