Is there a performance difference between round, oval or forward facing air filters?

  • Iron Eddie
    Iron Eddie
    13 years ago

    Howdy, just wondering what, if any, difference there is between the styles of air filter.  I'm planning to upgrade the air intake (including the back plate, not just the filter alone) on the bike and want to know if there's any difference.  I'm looking either the K&N units which appear to be the same as the HD Screamin' Eagle jobbies.  I've also come across the NRHS Hurricane filters that take care of oil blow-by (www.nrhsperformance.com/partshurricaneflow.shtml#HurricaneFlow%20Air%20Cleaners%20Installation%20Accessories) units that boast extra power over the other two. 

    I can live with the looks of any of the three, but the bottom line is what's the performance difference.  Does anybody know?

    Cheers for input.

     

     

     

  • slapster
    slapster
    13 years ago
    I saw a thread on another forum where a bloke dynoed the standard stage 1 SE filter against the SE heavy breather on an EFI 883 & from memory the standard SE filter ran about 1hp better over a couple of runs. I'd say the heavy breather would come into its' own though when the two are really pushed, say on a worked 1200/1250. Out of the three you mention I'd be looking at intake design for the smoothest (intake) air-flow, wouldn't think there'd be much in it though between them? The Hurricane looks the biz (would look sick in black finish) & NRHS have a good rep, I went with the round NRHS item though cos I could choose my finish/colour & faceplate design. As for the oil blow-by, you can use breather bolts or similar to adapt most air cleaners to breathe externally.

    My 2c.

    Slap.
  • Iron Eddie
    Iron Eddie
    13 years ago

     Cheers for info Slapster, I had a chat with a Dyno tuner today in Adelaide, he said the forward facing filter will produce more power but also mentioned the inlet size matters just as much as the surface area of the filter (which makes sense to me).  I discussed the NRHS Hurricane, he'd be very interested to Dyno one fitted as he's heard good things about them.  I am just about sold on that option I reckon.  I think i'll go with the round unit for my bike.  I'm happy to post the Dyno result which should show a comparison between the original filter and the NRHS jobbie. Stay tuned.....Now trying to work out the exhaust, want to stay with a 2 into 2 unit although I know 2 into 1 would be best.  

     

  • slapster
    slapster
    13 years ago
    No worries Iron Ed. I've been wanting to get my bike dynoed too, just a matter of priorities, and I really want a big bore kit asap. Definitely be interested to see your results with the NRHS a/c. I looked at the oval Hurricanes but prefer the compacter size of the round unit & the colour/faceplate options. I've got a horseshoe & catch-can oil breather setup on mine, its made no mess on the bike at all after 3000kms, just a light misting on the top of the catch-can itself. Also, if yr gettin the round NRHS, don't forget to have a play with designs/patterns etc for the faceplate, as long as it's not too detailed they can machine it. As for exhausts I was sold on the V&H 2-1 before I even bought my bike, I did look at the Sideshots as well for their "power chamber" design but the deeper rumble of the 2-1 Comp pipe pretty much had me hooked from the start. Hey if you want any more info/pics re the round a/c let me know. Likewise with the pipe if yr lookin at the Comp 2-1 at all. Anyway cheers & keep us all updated...

    Slap.
  • Iron Eddie
    Iron Eddie
    13 years ago

     Pics would be good, I looked the images on the NRHS webiste but would be interested to see how the horseshoe and catch can set up works...if you have time....

    Cheers

     

     

  • slapster
    slapster
    13 years ago

    Catch can product info here - http://www.golanproducts.com/breathers.html

    The horseshoe breather is a Drag Specialties item (includes hardware & hose) & this is the setup on my bike.

    Air cleaner was US$234.95 total incl. black anodised finish. Catch can was US$29 & horseshoe breather kit US$30.

    Cheers.

    Slap.

  • Iron Eddie
    Iron Eddie
    13 years ago

     Thanks Slapster, looking at your images and those in the NRHS website shows they use 2 hoses and catch cans, one for each cylinder by the looks of it, your set up is much cleaner.  I'll contact them and see if they can engrave my user image in the filter cover, that would be heaps cool....I want to keep the black look and would have it anodised either way.

    I really like the look of the RSD air cleaners but at twice the price I reckon the NRHS will do the job just fine.  Having said that the RSD units look the business for sure. www.rolandsands.com/categories/air-cleaner

    After speaking with the dyno guys, i'm changing my mind about the exhaust choice, don't want to take this thread off topic, so will either PM you or add to an existing thread regarding exhaust.

     

    Cheers

     

  • slapster
    slapster
    13 years ago

    Yep, the RSD Turbine Black Ops was on my short list.

    As for the engraving of yr user image, it may be too detailed. They couldn't do my Motorhead warpig logo either. I can however flip the cover & put a decal or sticker on. Probably the Motorhead logo or something Maiden (big fan).

    On a side note see T1 got his Iron dynoed  http://www.hdforums.com.au/Default.aspx?tabid=71&forumid=27&postid=448331&view=topic

    Slap.

  • terroristone
    terroristone
    13 years ago

    My air cleaner is an S&S style type from VPW, the casting is a little rough so i took to it with a dremel and polished it (10 mins work), basicly the base plate is like a trumpet, it will help with air flow/speed which helps with cylinder fill, An extremely free flowing air filter should also be considered. Mine is sponge and oiled lightly. I took what i have learned over the year on cars and put it to use on my bike. if the air quality was better all i would run would be a forward facing trumpet! I belive the NRHS air filter uses a similar base plate as the S&S and a price to match. Also make sure the hole thru the middle is exactly the same as the throttle body inlet, anything that can change flow will!!!!!

    T1

  • Freespaceage
    Freespaceage
    13 years ago

     Just replaced my Screaming Eagle air cleaner with the heavy breather, raining at the moment so will have to wait for a test ride. Looks awesome though.............

    Before.....

     

    After............

     

  • Iron Eddie
    Iron Eddie
    13 years ago

     Kia Ora, you'll have to take it for a blast around the Port Hills!!

    It would be very interesting to see the dyno results when you have it re-tuned for that cleaner.  If you have time it would be good to put them up on here.  I'm going to be getting the NRHS jobbie and will put the results up here.  I know it is difficult to compare different bikes and dyno machines etc, but i'd be looking for the comparitive difference between the original and replacement.  My dyno tuner said the forward facing ones generally produce the best improvement so it would be interesting to see what figures you come up with.

    Cheers

     

  • slapster
    slapster
    13 years ago
    ^ Yep some awesome riding around them Port Hills & over to Akaroa. I miss the South Island roads big time - except in winter gotta watch that bloody ice...

    Anyway yeah bring on the dyno!

    Slap.
  • Iron Eddie
    Iron Eddie
    13 years ago

     @ T1 and Slap, if you guys have the time could you take a pic of the intake and and mounting plate of your A/C, then post them up?

     I noted with interest T1 describing the VPW/S&S mount being similar to that of the NRHS.

    Cheers

     

     

  • slapster
    slapster
    13 years ago
    Iron Ed there's a pic of the NRHS round air cleaner internals on their air cleaner page. Sorry I ain't got a pic handy of mine at the minute.

    http://www.nrhsperformance.com/partshurricaneflow.shtml

    NRHS info - "This filter has been dyno proven to support engines making in excess of 90+ horsepower. And the CNC machined radius ring boosts both velocity and reduces turbulence."

    Cheers.

    Slap.
  • Iron Eddie
    Iron Eddie
    13 years ago

     Thanks for link Slap!