is there a big differnce between uni and k&n filters and which is the best one for performance

 

You'll probably get quite a few voting each way on this one, even though I think you'll get more votes for the K&N. I haven't used a UNI but I do have a dual stage foam NOTOIL, which is similar (and touted to breath as well as K&N), and a high flow K&N and I'm not sure that I can really notice any difference in performance between them. I do believe though that push come to shove, a good dual stage foam filter is gonna give you the best possible filtration, especially on dirt.

 

A K&N is great in a environment where dust and sand is limited. If you ride on dusty trails or do the sand dunes, then go with the UNI dual stage filter. You can also get Outerwares for both brands.

 

i am mostly running back woods out here in pa so youre saying k&n would be best

 

KN flows the best. Foam cant match the flow rates of the paper/cotton or whatever KN uses. However, foam can tbe beat for protection. I use the KN with no outer. To me, I'd rather have the extra power and deal with the consequences years from now in valve damage. No big deal. But I have a 1/4 liter engine too. Some guy with a 700cc engine can get away with a restrictive air filter, quiet exhaust, and all the comforts of home and still have enough power left to have fun. My 250cc cant deal with all that n still have power. So, that's how I look at things.

 

i am thinking about going with k&n velocity kit from alba and a power lid with the prefilter

 

Hmmmm..filters 101..LOL
IF you are a serious racer, have a highly modified motor, run a high rpm, and have resources to keep a motor fresh, the K&N is for you but never w/o an outerwear.
K&N's are made from a cotton mesh. I put one on my motorhome but it's all road miles.

A foam filter will give the best protection of the 2 styles.
Sparks makes a nice foam outer for a K&N style. Prolly the best of both worlds.

IMO:: A good foam filter with some 10-40 oil on it will be your best bet for a long lived motor in the woods of PA (that's where I ride).
I've ran both. Performance is the same for me and I have a modded motor and run high rpm's (cuz a 250R can).[img]i/expressions/face-icon-small-smile.gif[/img]
I'm sticking with the foam till I hit a TT track.

SO, for what it's worth,
I'm talking with Curtis Sparks as he's working on my daughters race machine. Seems dirt has gotten in and is mucking up the valves. I said "I told her to run a foam outer".
His reply was "most have to learn the hard way". [img]i/expressions/face-icon-small-smile.gif[/img]

 

what site would be the best to get one of those

 

<div class="FTQUOTE"><begin quote>Originally posted by: JustRandy

KN flows the best. Foam cant match the flow rates of the paper/cotton or whatever KN uses. However, foam can tbe beat for protection. I use the KN with no outer. To me, I'd rather have the extra power and deal with the consequences years from now in valve damage. No big deal. But I have a 1/4 liter engine too. Some guy with a 700cc engine can get away with a restrictive air filter, quiet exhaust, and all the comforts of home and still have enough power left to have fun. My 250cc cant deal with all that n still have power. So, that's how I look at things.</end quote></div>

With a modded engine I still don't think that the little bit of power difference is worth the cost of the potential motor damage. I'm running a 440 BB with cam and carb mods +++. Maybe that's why I barely notice any difference in power between the NoToil and the K&N. If you're in dust or sand I can't see going K&N....unless you're makin' the big bucks and don't mind the risk of suckin' dirt. Oil or no oil, hold a clean K&N up to the light and look through the inside. Now do the same with foam.... I know a team that races go-carts and dirt bikes and they all use NoToil dual stage filters and still win races.....Speaking of which, why don't dirt bikes use K&Ns?

 

I put a KN with no outer on my 230 quadsport in march last yr and ran it all though the dusty drought we had here in GA last summer. The engine was rebuilt also last march with new valves n wiseco piston. I just took the engine apart a couple weeks ago to inspect it and possibly mill the head and maybe some porting. The valves still look new. No wear at all. ....and just before I took it apart I had over 200psi compression with the kickstarter (no electric on this quad). I figure at this rate I should be good for a few yrs with a KN at least. Hopefully next yr we'll have some rain too, that will help lots of things, including my filter, lol.

I think the most likely cause for dirt to get in past the KN filter is improper cleaning using compressed air or a brush. All you have to do is tear a few fibers and you have a decent sized hole for dirt to get in. And oil won't plug that big of a hole either. Another good way for dirt to enter is around the seal in the airbox. I use 2 foam seals and use a crow bar to pry to filter in position to line up the holes and then tighten the screw. No way dirt is getting past that!