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stevethe

WR450 - Air Filters Review

15 posts in this topic

First I must say I am a long time Uni filter user as they were the only filter that didn't kill my horsepower on monster power hill climbs. However I believe they are about the biggest POS ever made in respect to the cheap glue they use on the outer foam. It simply falls apart as in gets De-laminated for no good reason. I have had almost new filter after filter thrown in the trash. I even tried cleaning it in cold water with dawn and the glue failed. They make other dirt bike filters that do not use the worthless glue that comes on the WR450.

 

I even called them and asked if they would please use other glue that works. Well they sent me a couple of filters with their cleaner and oil and said to use it. They still fell apart too soon.

 

So I have been on a mission not to loose the power of my built 450 to a lessor filter but I knew the Uni had to go. So I guinea pigged about all the air filters that I found on the internet. Unfortunately for me it was the last filter ordered that did the job. However I am still happy due to my findings. Bigger filter = more power.

 

The filters we use are shared with the WR250's. Now does this mean they put a 450 air filter in a 250.  Ah no. It appears we end up with a power robbing 250 filter in a 450. 

 

Oh and by the way remove the power robbing back fire screen from the cage. I use the billet ones with no back fire screens or carefully cut out the screen from the stock cage. There was also a 250 cage that came without the screen.

 

On to what works: PC Racing Flo air filter Mod. PCF1X.  It is Hugh at first I thought that the larger filter might not breath too well as it could be too close to the air box. Well that was not the case. More power everywhere down low mid range and especially top end. So I should also say my bike is built and the air box is opened everywhere I could, well it could be opened way further on the sides which I don't do due to water issues. The top is opened everywhere I could and four 1" uni vents service on both sides so eight total. I also run the smaller Li po battery for more air room on top.

 

Below are pictures of the filters some are quite puny.

 

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Filter%202_zps5kv3yrgm.jpg

 

 

 

 

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Just throwing in here that Twin Air has the Powerflow System available for the WR450, which for $130 eliminates that backfire screen, increases filter size and quality, and provides a billet aluminum clamping mechanism as a means of locking down the filter for a tight seal.

Edited by Texas2Smoker

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Sounds like you have been leaving too much oil behind in your filters........

 

Well I do drench them in a bucket and then paper towel them after. I use to use Uni oil now I use No Toil oil and filter grease. Same I use on the new filter. I can also say highly built road racing YZ450's benefit greatly from removing the entire restricting air box and installing a hugh K&N poking out of the rear fender as in. RR_zpsq71adkjq.jpg

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Just throwing in here that Twin Air has the Powerflow System available for the WR450, which for $130 eliminates that backfire screen, increases filter size and quality, and provides a billet aluminum clamping mechanism as a means of locking down the filter for a tight seal.

 

The Twin air cage is good the filter size is very puny and power robbing. The Uni is way bigger and the power flo even way bigger than the Uni.

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The Twin air cage is good the filter size is very puny and power robbing. The Uni is way bigger and the power flo even way bigger than the Uni.

Very puny? Isn't the Powerflow filter a good bit bigger than the stock one? Either way, it's enough for me, as I'm not looking for a huge power boost, I just want my bike to breath a little better, and I think the powerflow kit in combination with a higher flow exhaust will do the trick.

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First off, you don't get 'more power' with a bigger air filter.

You get more air flow, which if you take advantage of with proper jetting and pipe, will give a percent or more in the peak HP.

If you open up the head, 5 angle cut the valve seats, put in more agressive cams, then MAYBE you would measure a difference with air cleaners under normal off road conditions.

I know with my port and polished YZ cam'd WR there was no difference with or without the air cleaner, until you got above 50 mph and were wide open for at least 5 seconds.

Pretty much means only wide open flat terrain or hill climbs, where it might make a difference. 

 

 

I run nothing but ProFilters in all my bikes, because they are longer lasting and cheaper than everything else, AND because of their larger suface area, I can go a ride or two longer before I start to feel the dirty air cleaner bog.

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First off, you don't get 'more power' with a bigger air filter.

You get more air flow, which if you take advantage of with proper jetting and pipe, will give a percent or more in the peak HP.

If you open up the head, 5 angle cut the valve seats, put in more agressive cams, then MAYBE you would measure a difference with air cleaners under normal off road conditions.

I know with my port and polished YZ cam'd WR there was no difference with or without the air cleaner, until you got above 50 mph and were wide open for at least 5 seconds.

Pretty much means only wide open flat terrain or hill climbs, where it might make a difference. 

 

 

I run nothing but ProFilters in all my bikes, because they are longer lasting and cheaper than everything else, AND because of their larger suface area, I can go a ride or two longer before I start to feel the dirty air cleaner bog.

 

Well to each his own. Not my findings. The Pro filter in the picture and the Twin Air 's will not make the hills.  The PC Racing filter is the best off idle power I ever spent for $30. The pro filter in the picture was the smallest I bought.

Edited by stevethe

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Ever see the loudmouth mx intake?  The thing the cage attaches to gets replaced with a 4.75" round flange and you get a big clamp on filter.  I don't have one but I might try it someday.

Edited by chewbaccauncircumcised

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Ever see the loudmouth mx intake?  The thing the cage attaches to gets replaced with a 4.75" round flange and you get a big clamp on filter.  I don't have one but I might try it someday.

 

Getting a large enough filter to fit the MX intake will be the trick.

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Just throwing in here that Twin Air has the Powerflow System available for the WR450, which for $130 eliminates that backfire screen, increases filter size and quality, and provides a billet aluminum clamping mechanism as a means of locking down the filter for a tight seal.

 

im running the twin air system in my bike that replaced my falling apart gytr one. My bike has a full exhaust and hotcam and i cant say I feel my moneys worth in power, but using with no-toil oil the filter will be caked outside and spotless on the inside which is the most important part for me.

 

 

 

I know what you said but just cant see a simple filter change giving you such dramatic results

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Steve is sometimes climbing 300' vertical sand hills all day, and every tiny itty-bitty bit of extra power is the difference between getting to the top, and having to ride down a verticle avalance of silt....

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im running the twin air system in my bike that replaced my falling apart gytr one. My bike has a full exhaust and hotcam and i cant say I feel my moneys worth in power, but using with no-toil oil the filter will be caked outside and spotless on the inside which is the most important part for me.

 

 

 

I know what you said but just cant see a simple filter change giving you such dramatic results

I also tried the twin air billet cage and filter. I Ended up throwing away the filter and used a Uni instead.

The PC racing filter fits the Twin air cage.

It costs $30. to try it for yourself.

Steve is sometimes climbing 300' vertical sand hills all day, and every tiny itty-bitty bit of extra power is the difference between getting to the top, and having to ride down a verticle avalance of silt....

So all true we do big hills and you can feel the power one way or the other. It's funny the bike was ripping so hard in third gear up the hills that everyone thinks I did some big mods to the bike recently. I'm still laughing at the $30. big mods.

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