Page 1 of 2 1 2 LastLast
Results 1 to 10 of 18
  1. #1
    mxl16's Avatar
    Join Date
    May 2005
    Location
    Central NJ
    Posts
    1,590

    prefilter over air intake causing lose of rpms

    just thought i would share some info on prefiler material. ever since the begining of this riding season i have been searching for some lost rpms. After speaking with a few forum members, I decided to do a back 2 back test with and without the prefilter over my rear air intake.

    with prefilter = 7600-7650, without = 7800-7850. 200 rpm difference . i know Dan (rxp'in in mi) has personally been to the outerwears office/facility in MI and was told by an employee that it does in fact restrict air flow.

    i also removed the 2 flow rites i had in the grab bar and that gained me another 50 rpms.

    to solve the problem, i am going to attach a fine wire mesh/window screen over the rear intake where the prefilter material would sit. the mesh would be fine enough to break up any big water drops and keep debris out. i will leave the 2 flow rites in the grab bar for piece of mind since i do ride in rough conditions form time to time. i am going to make a "cover" for the air inlet to be placed on when trailoring so no dust or anything can get in there while on the road.

    btw, i dont have the riva "pro series" prefilter ($159). its just a piece of outerwears i cut to size. im not sure if the riva is the same or not.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	PDR_1202.JPG 
Views:	89 
Size:	344.3 KB 
ID:	24652   Click image for larger version. 

Name:	Rr%20air%20intake1.jpg 
Views:	93 
Size:	870.0 KB 
ID:	24653  


  2. #2
    CRAZEDRXP's Avatar
    Join Date
    Apr 2005
    Location
    PHILADELPHIA
    Posts
    843
    Just to add to this thread A few yrs ago Jerry and I did back to back tests And even waited to our skis cooled off with the pre filters on the original riva intakes , the pre filter made No difference at all we did the tests then called each other up to share results way back ... neither of us lost any RPMs

  3. #3
    HOSS's Avatar
    Join Date
    Aug 2005
    Location
    Kenner, LA
    Posts
    4,759
    +1
    29
    I`ll dare to differ with ya. But I`m a daring kinda dude. In the world of EMS and fuel injection,,,everything counts. Everything has a bearing on everything else. When the mods go up, the little things make a difference.

  4. #4
    ou812's Avatar
    Join Date
    Jun 2006
    Location
    Riverside,ca
    Posts
    6,210
    +1
    198
    Quote Originally Posted by mxl16 View Post
    just thought i would share some info on prefiler material. ever since the begining of this riding season i have been searching for some lost rpms. After speaking with a few forum members, I decided to do a back 2 back test with and without the prefilter over my rear air intake.

    with prefilter = 7600-7650, without = 7800-7850. 200 rpm difference . i know Dan (rxp'in in mi) has personally been to the outerwears office/facility in MI and was told by an employee that it does in fact restrict air flow.

    i also removed the 2 flow rites i had in the grab bar and that gained me another 50 rpms.

    to solve the problem, i am going to attach a fine wire mesh/window screen over the rear intake where the prefilter material would sit. the mesh would be fine enough to break up any big water drops and keep debris out. i will leave the 2 flow rites in the grab bar for piece of mind since i do ride in rough conditions form time to time. i am going to make a "cover" for the air inlet to be placed on when trailoring so no dust or anything can get in there while on the road.

    btw, i dont have the riva "pro series" prefilter ($159). its just a piece of outerwears i cut to size. im not sure if the riva is the same or not.

    I found I was missing 240+ rpm doing what you did but up front.

    Remember, water has to go somewhere when sitting on the screen & it can only go down...Not Good.

  5. #5
    HOSS's Avatar
    Join Date
    Aug 2005
    Location
    Kenner, LA
    Posts
    4,759
    +1
    29
    BINGO,,,this is what I experience evrytime riding witht he rear inatke. I wont ditch it,,but if i rode flat,,,id run no screen.

  6. #6
    Moderator The Bandit's Avatar
    Join Date
    Jul 2006
    Location
    Wilmette, IL
    Posts
    8,373
    I got it up front with a 4 inch intake. no rpm loss with stage 1, but now you guys have me thinking... I will test with/without tomorrow

  7. #7
    HOSS's Avatar
    Join Date
    Aug 2005
    Location
    Kenner, LA
    Posts
    4,759
    +1
    29

    Talking

    Without question,,lemme put a screen in front of your mouth when you breathe. Bet you wanna remove it.

  8. #8
    Moderator The Bandit's Avatar
    Join Date
    Jul 2006
    Location
    Wilmette, IL
    Posts
    8,373
    not if it stops the stems and seeds from going down my throat...

  9. #9
    HOSS's Avatar
    Join Date
    Aug 2005
    Location
    Kenner, LA
    Posts
    4,759
    +1
    29
    my motor turns that to non existence. That means not even ash.

  10. #10
    GTXX's Avatar
    Join Date
    Jan 2006
    Location
    NW, GA
    Posts
    1,776
    on two strokes with Prok flame arrestors the outerwears dropped 60-70 rpm. if the area of the prefilter material is large enough it won't affect RPM.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 2006 RXP Fresh Air Intake in front of seat questions?
    By skigolfnut in forum 4-Tec Performance
    Replies: 4
    Last Post: 01-08-2012, 04:08 PM
  2. can water getting into the air intake cause oily exhaust?
    By djpeetur in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 07-02-2010, 12:03 AM
  3. put on air intake, but lose power and rpms?
    By dreww in forum Kawasaki PWC Performance (4-stroke)
    Replies: 4
    Last Post: 06-18-2010, 12:08 PM
  4. Pics of JK's forced air intake system
    By River Girl in forum 4-Tec Performance
    Replies: 16
    Last Post: 03-09-2006, 10:24 AM
  5. Pics of my fan powered air intake
    By nitro rxp in forum 4-Tec Performance
    Replies: 6
    Last Post: 07-12-2005, 03:40 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •