Air Box Mod updated

[stingray719]

The last iteration of the air box mod has been fully tested and works slightly better than the original.

Heat pcv divider and bend over to minimize turbulence, as per first pic....
Remove snorkel from the lower air opening and do not reinstall.
Cut out are as per second pic but be careful you don't damage frogskin. This one looks a little rough as pic was taken before finish work.

EDIT 10/05/2015: Jim from EVO says the EVO 2.5 ECU flash will allow this mod to be used with an aftermarket can. Gives you the proper fueling and no starter kickback along with rev limiter raise. Link below.

http://www.evopowersports.com/Yamah...archPage=2&searchRank=salesrank&searchSize=12

EDIT: Please note in the picture that the raised ledge is also cut off around the hole, sorry if that is not clear.

TD MAX PICS
Here's how I did mine:

Snorkel:

Snorkel removed:

Divider Before:

Divider after:

Opening roughed:

Opening finished: The additional area of entry to the air box has increased by approx. 2/3 of what it was stock.

Note: I put a couple of small dabs of silicone where the frogskin material contacts the cut out support ribs.
This ledge in TD Max pics still needs to be removed and smoothed out. This is tricky part where screen get ruined if hit.

For anyone curious the part number for the "Frog Skin" / Filter is: 8JP-E445E-00-00
Questions? Go Here:
https://ty4stroke.com/threads/question-on-air-box.154303/

 

[cannondale27]

I bent that divider over with Excell airbox mod also. Thanks for reminding me! Sure goofy that they did that stock.

 

[stingray719]

I bent that divider over with Excell airbox mod also. Thanks for reminding me! Sure goofy that they did that stock.

Yeah creates a lot of turbulence the way it came stock.

 

[Blue Dave]

OK, before I start cutting and heating & bending my airbox I have a few questions. Specifically:

1) Where exactly am I cutting? Is there a template or measurements?

2) Where exactly am I heating and bending?

3) What exactly is the benefit? Is there dyno or drag race results to validate the benefit?

Thanks in advance for the help.

 

[NOS-PRO]

I want to add that I started out with Stingray's first mod on the airbox (with the 3 ports) and now running the airbox mod where it is cut below.

Wednesday I went out riding/testing and i opened up the original 3 ports about half way, this is the mod on the bottom and 3 ports 1/2 way open....WOW! The EVO header and exhaust really opened up now for power and have to add more weight to clutching. This thing is crazy on power now

 

[NOS-PRO]

OK, before I start cutting and heating & bending my airbox I have a few questions. Specifically:

1) Where exactly am I cutting? Is there a template or measurements?

2) Where exactly am I heating and bending?

3) What exactly is the benefit? Is there dyno or drag race results to validate the benefit?

Thanks in advance for the help.

Blue Dave, I believe Stingray has all the pictures and measurements, but I can tell you it makes a huge improvement in the midrange! just between my drag runs on asphalt between stock airbox and modded, I gained 4mph in the 1/8 mile....that's huge!

 

[Blue Dave]

Wow! You have my attention now.

Stingray,

Please elaborate on the details.

Thanks again for all of the help!

 

[TD Max]

Stingray,

Maybe some side by side before and after pics? This should help with the questions.

I might try to do mine and could see about taking some hi res images if you like.

NOS PRO,

Are you running the 3 port mod plus the revised cut open entry or are the original 3 holes now blocked?

 

[stingray719]

Let me shed some light on the two versions. The "3 hole" version was the first design, it is beneficial if you have added goodies like a trick header. The version above is for stock muffler fairly stock sleds. The reason for not having the holes is to keep the air velocity up on stock sleds. On sleds like NOS-PRO that need more air than stock opening the box up by adding the 3 holes creates a small amount of turbulence but the added air makes up for it. So if you have a header or modified engine run the three holes like my original version, but if you are just wanting a noticeable horsepower increase without buying controllers and such run the version above.

 

[NOS-PRO]

Stingray,

Maybe some side by side before and after pics? This should help with the questions.

I might try to do mine and could see about taking some hi res images if you like.

NOS PRO,

Are you running the 3 port mod plus the revised cut open entry or are the original 3 holes now blocked?

I ran the 3 port when I didn't have the header on asphalt, worked great!

Installed the header and it worked good, but thought it needed more.

Did the revised opening entry and ran this weekend with the original 3 ports open 1/2 way....working great with the EVO header/muffler combo and PC5. AFR readings - 12.5 at idle, 13.7 midrange and 12.1 full throttle.

 

[TD Max]

What are you guys cutting with a thin wheel?

 

[stingray719]

First one I used a cutoff wheel, second one I used a cutter that came with my cordless drill it looks like a piece of hacksaw blade mounted horizontally.

 

[cannondale27]

I used a Rotobit in diegrinder at slow speed

 

[Blue Dave]

is there a template, drawing, or picture with dimensions that will show me exactly where to cut?

 

[TD Max]

I used a Rotobit in diegrinder at slow speed

Ah I have a nice pencil grinder that should do well. I should have some nice bits. Probably nothing as coarse as a rotobit, but small carbides.