Secondary Butterfly Questions

Discussion in 'Rocket Performance' started by Pig9r, Apr 9, 2006.

  1. Pig9r

    Pig9rLiving Legend

    Country:
    United States
    Messages:
    4,925
    Featured Threads:
    204
    Media:
    193
    Likes Received:
    165
    Trophy Points:
    763
    Location:
    Kansas City, MO USA
    I was spending some quality time with the Rocket III service manual and came across the description for the second throttle stepper motor. In that description it states "The second butterfly optimises engine torque by maintaining intake air flow speed. It does not act as a choke for cold start purposes."

    So I started to google search the topic and found that Suzuki uses the same for its bikes to increase torque and smooth throttle response.

    Quoted from http://www.media.suzuki.com/svlaunch/fuel.htm

    Upon further reading from other sites much of the same reasons are given however I found on the 2005 GSXR-1000, Suzuki has added a second set of injectors just below the secondaries that spray at higher rpms.

    Also found that the Triumph Daytona 600 has secondaries. Jamie I wonder if your 675 does.

    The Caviga Raptor 650 also: "It now has a dual throttle valve fuel-injection system with secondary 39mm butterfly valves housed in each throttle body throat to control air intake and maintain air-flow velocity to match power output."

    The logical arguement to these claims would be that if they don't limit power then why do they stay open in third, fourth and fifth gears? Well a potential retort is that torque isn't as big of a factor once your rolling at a higher speed, that is where hp matters. Right? So is it possible that the secondaries are in place to deliver more torque in the first couple of gears?

    Does Triumph's use of the term "optimize" to mean smooth delivery or highest potential?

    I know Tom can attest to the fact he felt more power off the line once they were removed. Anyone dynoed before and after? Are the secondaries just to smooth throttle response at lower RPMs and the other claims just propaganda? Do the secondaries increase velocity and help with fuel atomization? What was the origin of the 7% power limit?


     
  2. SteveRed

    SteveRed.060 Over

    Messages:
    120
    Featured Threads:
    17
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Sydney, Australia
    Speaking with Wayne from Tuneboy... He reckons it is a mistake to remove the secondaries. They are there for a number of reasons, NOT just to slow the bike down! Even when they are removed the mapping system thinks they are still there and delivers fuel etc as if they are in place! The fuel mix is different in first and second. I think you are on the right track here Pigman!
     
  3. Rayvin

    Rayvin.060 Over

    Messages:
    166
    Featured Threads:
    6
    Likes Received:
    22
    Trophy Points:
    18
    I know I'm exhuming an ancient thread here, but since everyone here seemed to agree that eliminating the secondaries (by removing them physically or via the ECU with Tuneboy/Tuneecu) is a no-brainer performance mod, it was one of the first things I did when I got my '06 Classic a year and a half ago. The bike had D&Ds on it and, once I installed a suitable tune (I believe it was 20050), the bike had the awesome power you guys all know about, easily lifting the front end (a time or two unintentionally with the wife on the back-she wasn't too thrilled) and smoking the 240 at will. This was all with just an underseat K&N (ductwork on bottom of seat removed) for the intake. It was, however, way too loud for me so I opted to sell the D&Ds and reinstall the stock mufflers along with a cat-bypass and proper tune. This was also much more suited to the RV campgrounds we stayed at throughout this past summer. Using TuneECU I've switched a time or two between enabling and disabling the secondaries, and what I've found is that (and this is only a seat of the pants observation) with the secondaries enabled, the beast seems to have more torque in the first 3 gears at the lower rpms I usually ride in (2 to 3.5k, especially when 2-up). Is this actually true? I plan on keeping the current set up, not going with triple K&Ns or high performance (and noise) pipes, and aren't looking for best quarter mile times. Oh, and I also like the additional engine braking with the secondaries enabled. Any input is, as always, appreciated.
    Vin
     
  4. Hardy

    Hardy.040 Over

    Messages:
    94
    Featured Threads:
    7
    Media:
    31
    Likes Received:
    40
    Trophy Points:
    18
    Location:
    Homburg-Saar - Germany
    Interesting discussion.

    I planned to reinstall my secondaries for another reason. Without the secondaries I get a chirping noise during the excellartion. It's a nontypical sound for a motorcycle and I dont like it at all.

    think if I will correct the secondaries I have still the possiblitie with TunECU.

    But to learn that is eventually consuming power - well thats different to all what I read before.

    I will keep a eye to this particular thread.

    Secondaries removal DIY
     
  5. Evil Mitch

    Evil MitchLETS RIDE

    Messages:
    4,091
    Featured Threads:
    53
    Likes Received:
    2,923
    Trophy Points:
    823
    Location:
    Brisbane Australia
    Ride:
    2004 Triumph Daytona 600
    I noticed absolutely no real change in power with my secondarys removed"seat of the pants observation" it just seemed to have a smoother throttle response is all.
    The GIpro/atre on the other hand woke her up down low because of the ignition timing being changed to that of the higher gears "from what i understand anyway"
    and its those first three gears that wher restricted 7% because of this .
    not because of the secondarys . removing them adds no extra power i think those that report more power from removal just have a vivid imagination lol :rolleyes:
     
  6. CanberraR3

    CanberraR3Living Legend

    Country:
    Australia
    Messages:
    10,936
    Featured Threads:
    30
    Media:
    139
    Likes Received:
    8,508
    Trophy Points:
    823
    Location:
    Canberra, Australia
    Ride:
    Thruxton, Tiger 800, Scrambler, Street Triple RS
    Very interesting. I removed them at the same time as installing a GiPro and commented at the time that I wasn't able to tell which mod did what. But the bike did have more power in 1-3 and most definitiely had smoother throttle response. By smoother I mean more direct; it did exactly what I said, when I said it. I'd probably rather not mess with putting them back in as I'd hate one of the screws to come loose - having been out and put back - but would be very interested to see what Rayvin and Hardy find out.
     
  7. Rayvin

    Rayvin.060 Over

    Messages:
    166
    Featured Threads:
    6
    Likes Received:
    22
    Trophy Points:
    18
    Now that makes more sense (seat of the pants sense) to me, Mitch. Is the GIPro the easiest way to change the timing in gears 1-3 (other than getting a PC5), or can I do it with TuneECU?
     
    Evil Mitch likes this.
  8. CanberraR3

    CanberraR3Living Legend

    Country:
    Australia
    Messages:
    10,936
    Featured Threads:
    30
    Media:
    139
    Likes Received:
    8,508
    Trophy Points:
    823
    Location:
    Canberra, Australia
    Ride:
    Thruxton, Tiger 800, Scrambler, Street Triple RS
    And yes, what Mitch said. The GiPro unlocks the 7% by 'fixing' the timing. Neither mod actually produces more power and until now I hadn't heard that removing (or eliminating) secondaries could have a negative effect.
     
  9. Rayvin

    Rayvin.060 Over

    Messages:
    166
    Featured Threads:
    6
    Likes Received:
    22
    Trophy Points:
    18
    Let's not forget that this thread originated in 2006. Not sure if that makes Wayne's comments to SteveRed in post #2 (regarding the mapping) moot since we now have TuneBoy/ECU, etc. to modify the fuel mapping. No?
     
    Evil Mitch likes this.
  10. Triple Trouble

    Triple TroubleThe Duk

    Country:
    Canada
    Messages:
    1,931
    Featured Threads:
    22
    Media:
    139
    Likes Received:
    2,216
    Trophy Points:
    323
    Location:
    Orchard Beach. Ont. Canada , London England
    Ride:
    '05 Rocket III '69 650SS, '63 Matchless G80CS
    Exactly! simply removing the secondaries does not change the fuelling. If the ECU thinks that the throttles are opened 60% then it will supply the appropriate mixture for that. Using TuneBoy or Tune ECU then the proper mixture can be supplied . Having said that I know there were quite a few that removed them and reported power gains with no ill effects.
     
    Evil Mitch likes this.
Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice