Air Box Lids...

[Chanman420q]

I talked to alot of people about running no air box lid and they all pretty much said dont because u can get dirt/water in there, well when i finnaly too it off and drove down my drive. i went bak up ad took a look at it and id dint relize how open it was and how easily something could get in there. Would drilling holes in it be good for performance yet still keep me safe, my trails arent that wet, not like im goin threw a river

[flyin#5]

alot of people drill holes becuase it is much safer. you can also look around becuase they sell little 1 inch filters that go in the holes of your air box and keep mud and other things out and limits down on the dust.

[Chanman420q]

You know where i can get those?

[4TraxRider]

Look throuhg a dirtwheels issue, or you can pretty easily make some with screen and 1 or 2 inch pvc pipe.

[Chanman420q]

which issue

rockymountainatv.com has em

[trxex]

uni, the company that makes air filters sells them .your local dealer should stock them.i have 12 of them in my air box lid.white brothers also makes them .if your dealer dont have them dennis kirk sells them $.9.99 per package of 6.get 12;)

i have heard that no lid has worse performance then drilled holes because there is to much air to get sucked in. you are supposed to drill a 4 inch square towards the back of the lid for best results. that what i heard

[Chanman420q]

yeah maybe

[RAPTORAZ]

Originally posted by QuadMX18
i have heard that no lid has worse performance then drilled holes because there is to much air to get sucked in. you are supposed to drill a 4 inch square towards the back of the lid for best results. that what i heard

There is no such thing as too much air. More air coupled with more fuel equals more power. As for airbox lid, mine got tossed years ago. The only disadvantage is now I have to clean the air filter more often. If you're really worried about mud and other debri, contact Sparks racing. They sell a sreened air box lid for the 400EX.

[jmoney45]

Check out http://www.ehsracing.com

I bought one of these and love it. You get a complete lid that is waterproof.

[Chanman420q]

that is pretty cool.. did u have to jet and what kind of filter did it come with?

Originally posted by RAPTORAZ
There is no such thing as too much air. More air coupled with more fuel equals more power. As for airbox lid, mine got tossed years ago. The only disadvantage is now I have to clean the air filter more often. If you're really worried about mud and other debri, contact Sparks racing. They sell a sreened air box lid for the 400EX.


true that there is no such thing as to much air but when the lid is off there is so much turbulence that less air flows into the engine compared to a hole in the lid

[methyman]

This is what I run on my air box. You can get one by clicking on the link
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6755&item=2405773406

true that there is no such thing as to much air but when the lid is off there is so much turbulence that less air flows into the engine compared to a hole in the lid

R U Sure?

[jmoney45]

Originally posted by Chanman420q
that is pretty cool.. did u have to jet and what kind of filter did it come with?

It doesn't come with a filter...just the lid. Seems kinda pricey but I thought it was well worth it. You will definitely have to rejet.

[KandK952]

that or you could just take the lid off, rejet and get an outerwear for the filter so mud and water cant get in. (it also filters out quite a bit of dirt before it reaches the filter.)

[300exTJjeeper]

Instead of buying all this mods, It is so simple as to drill holes on the lid and on the back side and put velcro tape on all sides and soem on another piece form that you can still blow air through and put it onl it keeps mud, and water out real good and just take if off and hose it down.

A simple fix to a 40 air box lid I think,

Just my .02

[JD400exrider]

I had a outerware velcro crap to hold it down. It lasted three rides and it tore. The EHS racing air box cover is sweet. Works well and it looks cool. If you have not cut up your stock lid then you can order the aluminum and outerware from him. I like it. I run a UNI filter with it.

[300exTJjeeper]

I've had mine for about a year now with no problems and runs great does not tear off. As far looks go yeah it looks great and sweet but to bad it's under the seat.

Originally posted by 440EX4me
R U Sure?

Im pretty sure i have heard this information from 86atc250r. He has a website with pictures, and his reason is much more technical then what i can say but u can contact him and he will let u in on it. He tested all different holes in the lid and no lid and found what works best. if i got the info wrong. sorry:D :blah

[MillerTime]

if you are wearied about turbulence block off the snorkel tube,
so that the filter is only getting air from one direction and that is from the top.

[RAPTORAZ]

Originally posted by QuadMX18
true that there is no such thing as to much air but when the lid is off there is so much turbulence that less air flows into the engine compared to a hole in the lid

Any air entering the airbox, whether it be from the snorkel or the missing airbox lid, will have turbulence. However the airstream will be straightened out as it enters through the air filter. That's why most engines will typically make more horsepower with a K&N filter than with no air filter at all.

[nakomis0]

When I had my Blaster, I had the air box lid modded with holes.

IMO don't mod your lid. Just ride without it.

If you ever go mud bogging, or ride in the rain, or ride where there is alot of water. You can just slap your lid back on. Its also nice if your quad is running lean for some reason or another you can throw the lid on for some quick jetting to richen it up.

I ride with my lid off all the time. I also keep my drain plug removed. I pretty much go through everything (in reason) , water, mud ect.

I would like to know if that turbulence part is true. Its kind of hard to believe it is. Carbs suck air with a pretty good amount of force, I would think the turbulance would have to be alot to effect it, but who knows.

[Chanman420q]

i think im just gunna get that lid with the outer wear on it.. it seems like a pretty good design, blocks out mud and water but its lin more air than with the lid on... seems like a flawless design.


also do you think its safe with a K&N? i guess uni does a better job but K&N gives more performance. Another idea is to run an outerwear on the filter and have this airbox lid. Would that be good?

Originally posted by RAPTORAZ
Any air entering the airbox, whether it be from the snorkel or the missing airbox lid, will have turbulence. However the airstream will be straightened out as it enters through the air filter. That's why most engines will typically make more horsepower with a K&N filter than with no air filter at all.

my point is since the lid is off air will not be entering as much as with holes. a quad going 30 mph with the lid off, the air will just pass over the airbox because there is so much force it will not be able to suck the air in because it is just getting carried away. Now if u just have a lid on with holes u stop all the excess air and allow a little more to come in and u can control the amount so that u have that hole allowing the maximum amount that the engine is able to suck in. Then it will work best. Not a big enough hole(s) u can still get performance, if u open it to much u start to lose performance again. Hopefully i explained it better.:D

[Cole]

I think someone should develop some sort of "Ram Air" funnel that forces air into the front of the air box, where the factory snorkel mounts at. Then run the funnel to the front of the atv, where the forced air would enter somewhere in the very front of the quad. Somewhere near the front bumper under the front fender. Just a thought.

[Foxrage]

Heres what i did it works great i never get any mud or water in there now. Holds up good too.

[RAPTORAZ]

Originally posted by Foxrage
Heres what i did it works great i never get any mud or water in there now. Holds up good too.

That's an interesting set up you have there. Doesn't it make filter cleaning a pain though. By the looks of the picture you have the Outerwears epoxied/siliconed to the box.

[Foxrage]

haha no its just glued to the inside of the stock lid that was cut.

[RAPTORAZ]

Originally posted by QuadMX18
my point is since the lid is off air will not be entering as much as with holes. a quad going 30 mph with the lid off, the air will just pass over the airbox because there is so much force it will not be able to suck the air in because it is just getting carried away. Now if u just have a lid on with holes u stop all the excess air and allow a little more to come in and u can control the amount so that u have that hole allowing the maximum amount that the engine is able to suck in. Then it will work best. Not a big enough hole(s) u can still get performance, if u open it to much u start to lose performance again. Hopefully i explained it better.:D

Technically the engine does not "suck" air. The cylinder is filled by atmospheric pressure. And a certain amount of turbulence is required to keep the fuel from falling out of suspension. As for being able to control the incoming air. All your doing by making holes instead of ditching the lid is make it harder for the engine to breathe. You'll never lose performance by cutting off the engines air flow. If it's lean then add more fuel.

[JD400exrider]

I would have to aggree with raptoraz. Basicaly the little filter hole inserts that you install on the lid i think have a more chance of clogging up with mud, duct and crap. The more the better. I did not want allot of water getting in so i have been running a outerwear EHS modified lid. It seems to work allot better than my last set up. I cut the same basic large opening in the lid and fit an outerwear over the whole air box and put the lid back on. It did not stay tight and it tore.

I will say this The two other 400 ex bikes i ride with are set up the exact same way, however the guy with no lid isrunning a K&N filter with an outerwear It seams to be little faster than my bike and the other guys. Both of us are running Uni filters. Is the
K& N giving him that little edge ?

:confused:

[David]

Tell me if you think it would work.

I ordered a UNI airfilter, Outerware for the UNI. I don't have any jetting, pipe, etc, and i'm at 1200 feet above sea level. I really don't want to jet my quad. I ride trails with mud and water, also I play at the sand pits.

If I were to take my airbox lid and turn it around so its backwards (it does fit). Then put 1 or 2 UNI airbox holes in the part that is pretty much vertical. Would this help for turbulance??? I think it would be hard to get water in by the carb.

[RIDER11X]

Originally posted by David
Tell me if you think it would work.

I ordered a UNI airfilter, Outerware for the UNI. I don't have any jetting, pipe, etc, and i'm at 1200 feet above sea level. I really don't want to jet my quad. I ride trails with mud and water, also I play at the sand pits.

If I were to take my airbox lid and turn it around so its backwards (it does fit). Then put 1 or 2 UNI airbox holes in the part that is pretty much vertical. Would this help for turbulance??? I think it would be hard to get water in by the carb.
Won't fit.:ermm:

[RIDER11X]

Read a good idea in another thread. For those w/ modded lids, In severly muddy conditions, attach a piece of thick open cell foam over your lid trapped between trhe lid and your fenders. Quad will breathe through the foam.

Originally posted by RIDER11X
Read a good idea in another thread. For those w/ modded lids, In severly muddy conditions, attach a piece of thick open cell foam over your lid trapped between trhe lid and your fenders. Quad will breathe through the foam.

I am currently working on something sort of in that direction but without any foam. The air box lid I use is a lot like the one above and theres a pic below.

I have been testing the restriction of diff air box and filter set ups since finally installing the UNI filter that I picked up as a spare months ago and finding that it did not flow the same as the K&N and richened up things a little. Since I dont have any flow equipment this will be both jetting and seat of the pants type testing.

Anyone else ever notice that even the outerware for the lid restricts air flow?