Small air box mod completed, BMC filter installed

[jay21112]

Ok, today I did some more work today and I think I completed the air box.

I did the small airbox mod by drilling holes all around the flapper then using a serated knife to cut out the flapper. Then I sanded it smooth (or as smooth as I could get it) with a file, a drill, and some sand paper.

Then I removed the intake air control valve actuator from the floor of the air box (and tossed it) and sealed the hole with some high heat silicone and the flapper which I cut into a circle with some shears.

I plugged the line leading from the intake air control valve actuator to the vacuum control solenoid valve with a left over valve stem cap from my car (and some more silicone).

Also plugged the pair valve hole with a cap from brock's pair removal kit (and some more silicone...getting the drill yet?).

Then....I installed the BMC race air filter and put everything back on the bike.

Now I have 2 questions....one major and one minor.

Look in the pics below...look at the one of the bottom of the airbox. There is a hole for a hose in the top of the airbox which I cannot remember removing a hose from. When I put the airbox back on the bike I couldn't find a hose to hook up to it. Is there a hose that hooks up to it? If not, should I cap it off and seal it?

The other question regards the BMC air filter. Look at the pic with the stock air filter. There is a piece of foam at the bottom of the pic. This came in the box with the BMC air filter but I have no idea WTF they want me to do with it. Any ideas? I thought maybe they wanted me to tape it to the bottom (inside) of the air filter...but I thought why?

So any help (especially in answering the first question) would be appreciated)

Here are the pics:

 

[jay21112]

Removed flapper

 

[jay21112]

Valve that I chucked...

 

[jay21112]

BMC new in box!

 

[jay21112]

WTF is that foam for???

 

[jay21112]

Installed

 

[jay21112]

Bump to see if anyone can answer my question:

Is there a hose that connects to the front of the airbox
(Circled in first pic), or should I seal that hole up?

 

[mountainmotor]

That's like another water drain hole or something.

Don't seal it , it's open from the factory .

 

[jay21112]

(mountainmotor @ Nov. 04 2006,05:49) That's like another water drain hole or something.

Don't seal it , it's open from the factory .

THANK YOU!!!

Much appreciated.

I've been going nuts trying to figure out what the heck went there as I couldn't find anything mentioned in the service manual.

I wonder why it's left open though?

There is a water drain hole in the rear of the airbox that comes capped from suzuki, do I wonder why that one doesn't come capped?

 

[Aquaman]

Can someone shed a little light for this dummy why I will need to do this mod. Is it because of installing this type of filter,or some other reason?

Thanks

nice write up pics too

 

[mountainmotor]

(jay21112 @ Nov. 04 2006,13:02)

(mountainmotor @ Nov. 04 2006,05:49) That's like another water drain hole or something.

Don't seal it , it's open from the factory .

THANK YOU!!!

Much appreciated.

I've been going nuts trying to figure out what the heck went there as I couldn't find anything mentioned in the service manual.

I wonder why it's left open though?

There is a water drain hole in the rear of the airbox that comes capped from suzuki, do I wonder why that one doesn't come capped?

It could be they wanted somekind of airbox pressure release/equalization outlet caused by the exhaust waves trying to come back through the throttle bodies under certain wot/rpm conditions . Maybe the waves are strong enough to jack with an adjacent cylinder yet not strong enough to overcome the ram air pressure inlet .

Don't really know , just a SWAG  

But do know the reason for the two long stacks and the intake pulses in the relative small airbox jacking with the outboard cylinders are in part , reason Suzuki used them .

 

[jay21112]

(brendanp @ Nov. 04 2006,08:15) Can someone shed a little light for this dummy why I will need to do this mod. Is it because of installing this type of filter,or some other reason?

Thanks

nice write up pics too

There are numerous posts here about the mod and tons of info and conflicting opinions.....but the way I see it is that below 2800 (I think) rpms the flapper stays half closed then above that it opens to allow more airflow. However that very flapper is a restriction point.

So, removing it allows for more airflow and more hp up top. However it may also remove torque under 2800 rmp (but who drives under 2800 rmp) becaue the flapper is there for a reason.

Most people say there is no benefit to doing this mod unless you get a full exhaust system. If you have a full exhaust and get remapped (with a PCRIII) you will see a big difference.

Me...I put in a race air filter, I'm modding the stock exhaust (but keeping the stock exhaust) and I'm gonna get a custom tune with a PCRIII. So we will see if it benefits me, but I don't believe it can hurt at all even if you were bone stock (although some people will argue otherwise).

Hope that helped, but like I said, I just kinda summed up the debate and didn't include ALL the details....

 

[jay21112]

(mountainmotor @ Nov. 04 2006,09:00) It could be they wanted somekind of airbox pressure release/equalization outlet caused by the exhaust waves trying to come back through the throttle bodies under certain wot/rpm conditions . Maybe the waves are strong enough to jack with an adjacent cylinder yet not strong enough to overcome the ram air pressure inlet .

Don't really know , just a SWAG  

But do know the reason for the two long stacks and the intake pulses in the relative small airbox jacking with the outboard cylinders are in part , reason Suzuki used them .

Ok someone knows WAY more then me.

haha.

Thanks for the explanation. Makes sense I guess, especially since I was just thinking it was a drain hole.

 

[Burger King]

(mountainmotor @ Nov. 04 2006,12:00)

(jay21112 @ Nov. 04 2006,13:02)

(mountainmotor @ Nov. 04 2006,05:49) That's like another water drain hole or something.

Don't seal it , it's open from the factory .

THANK YOU!!!

Much appreciated.

I've been going nuts trying to figure out what the heck went there as I couldn't find anything mentioned in the service manual.

I wonder why it's left open though?

There is a water drain hole in the rear of the airbox that comes capped from suzuki, do I wonder why that one doesn't come capped?

It could be they wanted somekind of airbox pressure release/equalization outlet caused by the exhaust waves trying to come back through the throttle bodies under certain wot/rpm conditions . Maybe the waves are strong enough to jack with an adjacent cylinder yet not strong enough to overcome the ram air pressure inlet .

Don't really know , just a SWAG

But do know the reason for the two long stacks and the intake pulses in the relative small airbox jacking with the outboard cylinders are in part , reason Suzuki used them .

WOW....I learned something new today...................I think

 

[sproket]

I had the air box mod for the longest time...it was all good except for the abrupt or uneven power in the lower rpm and the flat spots...Of course i did not have the full system to go with the air box mod either...I went for a ride today after removing the TRE and the Power commander, it was pretty good...