Removing secondary butterflys

Discussion in 'Mechanical & Technical' started by BigDZX10R, Feb 23, 2010.

  1. I have heard of taking the socondary butterflys out to give the bike more power but i havent come accross one that had it done.
    Has anybody done it and what difference did it make?
  2. Secondary butterflies are used on some Suzuki and Kawasakis to smooth out the throttle response and/or meet emission requirements. The rider opens the lower butterfly with the throttle, the upper butterfly is controlled by an electric motor receiving instructions from the ECM.

    Removing the upper butterfly will result in a much quicker throttle response and big torque increase in the rpms where the ECM normally would use the butterfly to restrict the air flow to the lower butterfly. It also can create a very lean condition in those rpms under wide open throttle conditions so most use a Power Commander to add fuel to compensate for the extra air flow...and avoid a burned piston.
  3. I have an 08 zx10 with full Leo exhaust and i am running a PCIII usb. That lean condition worries me a bit but i LOVE the torque and quicker thottle response. Sounds like the best bet is to get it on a dino if i do it...Thanks!
  4. Omg. just leave the damn things alone.

    But if you just CAN'T keep from fukking with it, just go to
    dwschultzy likes this.
  5. Im a big guy...I need more power to keep them 180lb kids behind me. Ill check it out. Thanks
  6. Unless you're talking drag racing (and if so, just buy a busa or zx14), spending your money on a good track school will make you a hell of a lot faster than removing the secondary butterflies in the throttle bodies ever will.
  7. Sell it and get a ZX-14 or Busa if you want more power.

    Honestly though, the ZX10 is a beast known for having a monstrous engine. I can't imagine why you'd need more power unless you're drag racing.
  8. kdunk

    Seattle, WA
    I second that, I weigh 205 lbs and my stock 08' 10r still scares me. I shifted it at like 10,000 rpm on the big downhill SR14 West on ramp just east of The Rock in Vancouver, WA and the front end was still coming up in 3rd gear.
  9. Maybe I should have clarified in my first post, the secondary butterflies only reduce air flow at the lower rpms, usually between 2500-5000, and have the greatest reduction in the first four gears. After 5000 rpms the torque and HP curves will be almost the same.

    The downside to butterfly removal is that the throttle response can be too sensitive in the lower gears in low traction conditions. Its hard to be smooth riding in the rain when you have to worry about wheel spin every time you leave a stop sign.
  10. VFRtard did it on his ZX14

    I did it on my Concours 1400

    it was easy ;)

    notable difference down low,
    just adjust your mapping on your PCiii

    after you pull the tank,
    pull the airbox covers
    use a soldering iron tip to heat up the fly's screws (they have blue locTite on them)
    should take you like half an hour

    nobody ever complains about the change (on the concours forums)
    I really liked the extra pull down low
  11. yup, i'm 230 without gear, and my 07 always pulls like a freight train.
  12. ok.. farmer method would be to pull the upper butterflies off.. drill some big holes in them and slap them back on... but that is just us idiots throwing ideas out there. Kind of the half and half solution.
  13. What kind of pussy mechanics are you guys?!?! Grab a hammer and knock them fuckers off.
  14. Sound like there is no duct tape nor baling wire available.. but it is all good :roll:
  15. james1300

    james1300 Track School Dazed

    I hear Banjo's warm'in up!
  16. I got a cousin that has both of his original front teeth... so we don't need to go there
  17. vagrant

    vagrant »-(¯`·.·´¯)-> PNW

    Seattle, WA
    After all of this, if you really really need more throttle response, search for the riflemans's throttle tube or smething like that. He mods the little cam/pulley thingy to make it less of a turn to WOT. Enjoy.

    (no I have not done it)
  18. Lone Rider

    Lone Rider Streetfighter

    :mppoint: funny too funny.

    You can get a PCIII at a dynamite price at fuelmoto. They haz maps too.
    Didnt know flies out was a common mod on the 10.
    Going down a tooth on your countersprocket works gooooood too.
  19. I skipped butterfly removal on my zx-14 and added Ivan's TRE, bike made great power down low.
    10 minute install and no removal of parts from the motor.

    imho leave the gearing alone.

    I wouldn't remove the secondary butterflys on the 10 either but to each there own.
  20. Im 265, not around the middle, and it brings the front tire up shifting into 4th! Custom race map on the PCIII. Ive SMOKED a busa twice and had it to 180 with more to go. Guess i really like the rush. Thing makes huge power but always looking for more... I really appreciate all the input though! Thanks!
    I dont dive a Caddy and i dont want a huge bike....

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