The XT660X/R Air Box & Filters
 

There still seems to be a bit of confusion over the XT's air box. I have done a complete explanation on the air box, filters & how it all works.

http://i201.photobucket.com/albums/a...evxtx/1-35.jpg

http://i201.photobucket.com/albums/a...evxtx/2-34.jpg

http://i201.photobucket.com/albums/a...evxtx/3-29.jpg

http://i201.photobucket.com/albums/a...evxtx/4-25.jpg

http://i201.photobucket.com/albums/a...evxtx/5-18.jpg

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The Yamaha air box is not really good for air flow. I am sure you can now see why you get good gains when fitting a DNA Stage 2 air box side filter in place of the Yamaha side cover. The stage 2 filter can supply air directly to the throttle body with no restriction.

http://i201.photobucket.com/albums/aa202/kevxtx/10a.jpg

You can only just see the main filter from the throttle body side, not good for flow.

http://i201.photobucket.com/albums/a...evxtx/11-8.jpg

You can now see why the DNA stage 3 Air box works so well with no restrictions with positive air flow & volume.

http://i201.photobucket.com/albums/a...xtx/2-31-1.jpg

Alot of riders are worried about removing the snorkel. I would recommend you to fit a stage 1 DNA air filter, these filters are oil based & repel water. Looking from the removed snorkel you can see the water drain hole into the air boxes 3rd chamber.

http://i201.photobucket.com/albums/a...evxtx/12-7.jpg

http://i201.photobucket.com/albums/a...evxtx/13-6.jpg

Finally the flow tests for the filters.

Hi Guys,
Following your request I have finally put together a presentation of the DNA P-Y6E04-01 Stage 1 filter compared back to back with the K&N YA-6604 Stage 1 filter, and more useful information that will help you tune the XT 660 R /X.

The results are very impressive and enlightening.
All the air flow tests took place the same day on DNA’s Rotronics Computerized FlowBench, the test pressure was 1,5” inches of water and the results corrected to 25� celcius.
1. Presentation of the air filters:

a) Stock Yamaha air filter, single layer paper non-reusable air filter
b) K&N YA-6604 air filter, 4 layer cotton oil impregnated reusable air filter
c) DNA P-Y6E04-01 air filter, 4 layer cotton oil impregnated reusable air filter

2. Air Filter Design (see attached files)

a) The K&N YA-6604 air filter:
Media material 4 layers of K&N cotton
Number of pleats 11
Pleat Height 21 mm
Active Pleat length 115mm*
Pleat Pitch 6,36mm*
Oil volume 7ml
Total active filtering surface 53.130�mm*
� * as measured from the K&N sample filter we purchased.

b) The DNA P-Y6E04-01 air filter:
Media material 4 layers of DNA cotton
Number of pleats 9
Pleat Height 31 mm
Active Pleat length 124mm
Pleat Pitch 10mm
Oil volume 16,3ml
Total active filtering surface 69.192�mm

As we can see the DNA filter has larger pleat height 31mm(K&N 21mm), the pleat pitch is 10mm(K&N 6.36mm), the amount of oil DNA uses is more than double, and the most important +30.23% more active filtering surface..! for the same application.

At this point I must explain that the pitch of the DNA material is calculated taking under consideration many different variables; we use a specially developed algorithm and the final design varies from application to application. Even 0.1 of a mm can make a very big difference in airflow, speed of the air stream at the surface of the filter, turbulence and many more details that we can’t mention for obvious reasons.

So already from the start we have2 very different air filters!

Let’s continue with the tests.

3. Absolute AIR FLOW tests: the filters are tested out of the air box on a custom made plenum; nothing causes turbulence or restrictions to the air flow
(see attachments).
The result is solely what the filter can give.

a) Stock Yamaha Paper Air filter
70.42 CFM @ 1.5” of H�O

b)K&N YA-6604
92.18 CFM @ 1.5” of H�O
+30.9% over stock

c) DNA P-Y6E04-01
122.4 CFM @ 1.5” of H�O
+73.81% over stock
+32.78% over K&N…?

4. Air Box AIR FLOW tests: the filters are tested inside the stock Yamaha air box,
To eliminate the losses (restriction) that the stock throttle body could cause we used a 48.6mm throttle body without the butterfly; the absolute largest that could be connected to the XT 660 Rubber trumpet.
Air box restrictions, shape, resonance, position of the air filter, if the design of the air filter suits the design of the air box and many more variables play an important role now.
Also I have added the Volumetric Efficiency (VE), of the XT 660 Engine, that occurs for every configuration, if the tuner takes 100% advantage of the extra flow.

a) Test 1:
Air box & std filter & snorkel
46.53 CFM (1318 lit/min) VE=0.539

b) Test 2:
Air box & K&N filter & snorkel
52.51 CFM (1486 lit/min) VE=0.608

c) Test 3:
Air box & DNA filter & snorkel
57.19 CFM (1619 lit/min) VE=0.663

d) Test 4:
Air box & DNA filter & Without snorkel
59.52 CFM (1685 lit/min) VE=0.690

e) Test 5:
Air box & DNA filter & DNA Stage 2 filter & snorkel
79.19 CFM (2242 lit/min) VE=0.918

f) Test 6:
Air box & DNA filter & DNA Stage 2 filter Without snorkel
79.89 CFM (2262 lit/min) VE=0.926

g) Test 7:
Air box all open Without filters, side cover, snorkel
(this test is for reference only the bike can’t be used on the road in this state)
88.6 CFM (2509 lit/min) VE=1.027

Finishing our detailed tests clearly the conclusion is That the DNA stage 1 filter is NOT the same filter as the K&N as the overall difference is Massive.


Also you can see why the fueling must be adjusted when going stage 2 and why you can get away with it, when removing only the snorkel.

I would like to thank to all the forum members for their attention, I hope everyone will enjoy the above info.

The Stage 3 DNA Air Box is the best by far.

• Extreme air flow 111,9 CFM @ 1,5 Inches of water
• + 40% more than the popular DNA Stage 2 application!
• + 140,49% more than the stock air box & filter!
• 98-99% filtering efficiency for maximum engine protection
• Unique DNA air filter with built in venturi designed to smoothen out the air flow
• Dyno proven +8 HP more power from the standard engine (with Powercommander or Race slip on’s)
• Dyno proven +14 HP more power from a highly modified 700cc engine
• Specially designed rubber velocity stack, increases and spreads torque over a wider rpm range, with the possibility to alter the tuned length for custom applications
• All standard parts bolt on or attach to the S3 Air box (Battery, ECU, Rectifier, Temperature sensor, Idle circuit, AIS circuit, Crank case vent, Rear wheel mud flap)
• Specially designed aluminium adapter that can be modified to adapt big bore throttle bodies
• Designed to be used in rainy weather (Att. Not to be completely submerged in water)
• Unique design of side covers & frame allows unrestricted air flow and catches the eye!
• Shipped ready to install, includes installation info, 2 Powercommander Maps, dyno Graphs, and air flow Graphs
• Limited production unit with individual Serial Number.

COR what a difference. Ordered a K&N filter, took the snorkel out and wallop, gutsy sound with standard pipes, loads more low down stomp and generally smoother and easier to ride

A great helpful thread, thanks guys! :notworthy[1]:

Tempted to do more now, but thinking that much more noise will be a pain around town

Hi Kev,
I believe the above is what you are looking for.
If you need more info please let me know.
Best regards,

Dino

Thanks Dino this is what I was looking for. I seemed to deleted the link from the mod section, have since found the comparison testing between the DNA & K&N filters.

http://www.xt660.com/showthread.php?t=9848

Help please with very poor running.
 

Hello Kev,
I have an 08 660x with scorpion cans runs like an on /off switch but at least a bit of acceleration now standard pipes are gone.Some questions please,does the snorkel just unbolt and if i take this off put in a dna filter and plug in a NITRO FUEL COMMANDER [can't afford a PC III or V] IF i do these mods will it run better and will i need an O2 eliminator,please advise because if i can't get it to run better it will have to go,i WANT to keep it but it runs terrible standard surges real bad,Thanks alot for any advice.gaz

The snorkel just pulls out,spray in WD and pull!!,I run mine with Kev's fuel mod,K+N 1 and DNA2 and no 02 eliminator, the bike runs fine.

All this info is on the site anyway,as I had pointed out too me on another site the search button is your friend http://www.xt660.com/images/icons/icon7.gif

Sorry to be a pain, I was wondering where to drill the extra holes in the standard airbox with the snorkel removed?? Not on the side cover as that is the filtered side, so around the snorkel "hole" I guess??? Thanks thanks thanks

All the info is in the mod book you bought yesterday, page 284 in the XTX & XTR mod section. To answer your question the extra holes are drilled in the snorkel chamber.

http://i201.photobucket.com/albums/a...tx/Modbook.jpg

Has anyone tested the otr foam filter how does it compare to dna1?

Im curious because im having custom map made to my bike on wednesday and i have dna1 now but i was thinking of changing to foam filter because i ride mostly gravel and off road.. problem is that i cant get a foam filter by wednesday but if there is not much of a difference then maybe go with a dirty filter :D

Im still confused what do i need to do for stage 2 filter? Just buy the filter and swap them over? Sorry im not brightest spark....


Xt660x 04

That's pretty much what you need to do if you want DNA stage 1 and 2.

Edit.. Stage 2 filter replaces the original airbox cover.

Got it all understood now thank you :)


Xt660x 04

Hey guys, couple of quick questions about drilling the airbox. In the modifications book it says to drill 30mm holes but I only have a 32mm drill bit will this be too big? Also should I remove the airbox to do this mod to be sure to get all the debris out?
Thanks in advance :)

Your probably OK with five 32mm holes, but it gives a bigger area. Four 32mm holes are closer in total area to Kev's recommendation:

5x 30mm holes give you an additional intake area of 3535 sq. mm

5x 32mm holes gives you 4020 sq. mm

4x 32mm holes gives you 3216 sq. mm

Or if you want to get it closer then 4x 32mm holes plus 1x 20mm hole will give you 3530 sq. mm, which is nigh on the same as 5x 30mm holes.

You can do it with the air box in place. You can vacuum out the debris afterwards. Most will comes outwards though with the drill. Alternatively you can put some grease on the drill bit so the plastic swarf sticks to it and does get spread about.

Thanks for the reply Pleiades, I managed to get hold of a 30mm drill bit in the end so have used that. However when I installed my DNA air filter I was surprised to find a K&N filter already installed! It was in there pretty tight and took some pulling to get it out, however when I installed the DNA filter the gap between the snorkel chamber and the filter was huge, a good few millimetres enough to see through to the holes I drilled in the snorkel chamber. It's nowhere near as snug as the K&N was and to be honest I'm a little concerned. Is this normal for the DNA filters? I plugged the gap with a healthy amount of grease but don't know if the air pressure might pull it loose. Does anyone else have this experience with these filters or any advice?

Awesome thread

on my xt660x

Ive just replaced my standard cans with a blackwidow exhaust system (2x300mm cans and link pipes)

And a k&n main filter today

What hp hike should i get from that please

Its running standard with no setup.

About 48 to 49 rear wheel HP from a standard 45HP, all the free HP is in the air box.

How do i remove this god damnit airbox? I made a homemade stage 3 k&n airbox. But i am about to wreck the stock one since i cannot remove it from the bike, its like trapped in the frame....

Thanks for that

Since my cans and k&n ive been experiencing some stalling so ill be adjusting fuel and idle tomorrow in the settings

Will i need the fuel mod for my basic setup do u think?

Ill be buying one eventually anyway when i get the dna 3 filter