PAIR valve blockoff

Discussion in '6th Generation 2002-2013' started by Def-E-nition, Mar 22, 2007.

  1. j.davis

    j.davis New Member

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  2. Spike

    Spike New Member

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  3. Spike

    Spike New Member

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    Along the same lines as this, has anyone come up with something to get rid of the ungly overflow canister at the bottom of our bikes?
     
  4. Def-E-nition

    Def-E-nition New Member

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    Pic ? What does it look like ?
     
  5. NorcalBoy

    NorcalBoy Member

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    Just take it off, remove the hoses and unplug the associated electrical connectors. I wrapped the connectors with electrical tape and zip tied them in place. You need to remove and remount the outside mounting bracket off of the cannister, as the right side fairing lower bolts onto it. I have removed all of the items associated with the emission controls, but I have saved all of the pieces in case I need them due to future regulations. It removes close to 5 pounds off of the bike.
     
  6. OKCVFR

    OKCVFR New Member

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    Sorry Def, but you are incorrect in the process of how the air injection works and it's affects. This is an emissions item yes, but the valve does not open and inject air accept on DECELERATION. It in no way effects the O2 sensors, this is a terrible mis-nomar that has been circulating for too long. Hence the reason you are not noticing any difference. By removing the pair valve, the only thing you are doing (besides inllegaly disabling emissions system :rolleyes: ) is removing a little weight, and very little at that.

    If you want to remove it and do away with a little decel popping that occurs that is great, but in the grand scheme of things it is doing nothing for you in terms of performance. And with the little, and I mean little, weight loss it provides, you gain absolutely nothing.

    Another thread on here I believe asks what mods are a waist of time and money, well this is one of them.

    Sorry to those who believe otherwise, but it is fact that the air injection is only happening upon decel and the only time the O2 is sensing anything and giving input to the ECM is when the throttle position sensor indicates throttle opening on accel.
     
    Last edited: Feb 28, 2008
  7. OKCVFR

    OKCVFR New Member

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    Sorry Friend, but your sequence of events above is incorrect. If you really look at the pair valve setup, you will see that it is vaccum controlled. When you let off of the throttle and decel the vaccum opens up the valves allowing fresh, filtered air to into into exhaust manifold. At this point the O2 sensor is not in the equation and not effecting the ECU.

    I undestand that when blocked that the decel goes away and it may slightly improve drivablitly but ever so slightly. There is absolutely no peformance gain. Don't believe me? take your bike to a dyno stock, make several pulls, then block the pair valves and make several more runs. The average of the pulls before compared to after will be the same.
     
  8. Def-E-nition

    Def-E-nition New Member

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    Can someone tell me if the overflow canister is on 6th Gen Models please ?
     
  9. RGonVFR

    RGonVFR New Member

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    I've seen a lot of info on this PAIR valve thing and noticed all of you are on 6th gen bikes with VTEC. Anyone with a 5th gen do this mod with any difference? Or do the 5th gens not need it because of the lack of VTEC?
     
  10. Ghost 1

    Ghost 1 New Member

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    Jev, I was just looking at your avatar.... I'm sorry, what were we discussing here again?:clap2:
     
  11. mello dude

    mello dude Member

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    Id like to find out on this one too - seems all the scoop is about 6th gens.
    Then again - I really havent found any reason to wanna screw with it either. My ride is smooth bottom to top.

    MD

    - Maybe start a 5th gen only thread on this?
     
  12. keeena

    keeena New Member

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    If PAIR only operates upon 0% throttle, why do dyno operators disable the PAIR for dyno tuning?
     
  13. junktionfet

    junktionfet New Member

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    Interesting thread...

    On every modern pulsed air injection system I've ever seen, the system is only used when the engine is cold and in open-loop mode. The oxidation reaction not only reduces HC emissions, but the heat generated by the reaction helps the catalytic converter start working sooner. However once the engine reaches a certain coolant temperature, the system is shut down because it adversely affects the readings from the O2 sensor.

    Has anyone checked to see if the PAIR solenoid is energized when the engine is warm? You can't check it with a VOM because the load is too light and normal leakage current from the transistors in the ECU will give you a false reading. You'd have to check it with an incandescent test light or the solenoid itself.

    This is more than likely the case, which raises the question why do some people claim to feel a difference with the hoses blocked off? Do you all ride with the engine cold or something? Or is it just a placebo effect?

    EDIT: I do recall one application where secondary air injection was used partially at idle on a "high performance" engine at operating temperature to help smooth out the idle (by providing the ECU with a false lean signal). A microswitch in the throttle disabled it off-idle though. This would also have an effect while coasting. Worst case, the VFR might use it this way. Some real tests would prove one way or another exactly how Honda uses it. The shop manual is worthless.
     
  14. NorcalBoy

    NorcalBoy Member

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    You have a very valid point there!.........Way to go Keeena, I think you might be on to something :biggrin:
     
  15. junktionfet

    junktionfet New Member

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    I've just proved exactly how the PAIR valve works on my '06. I needed to check the air filter anyway :)

    When the engine is below about 160 degrees F, the PAIR valve is always open--closed throttle, open throttle, revving, etc. This introduces fresh air in the exhaust ports, oxidizing CO and HC, and producing extra heat to light-off the catalytic converter.

    When the engine is above about 160 degrees F, the PAIR valve CLOSES as soon as the throttle is slightly opened. It OPENS again when the throttle is shut, regardless of RPM. This is probably done to provide a little richening at idle to smooth out the recommended 1200 RPM idle speed.

    Therefore, any change in the engine behavior by blocking the PAIR valve would have to be a coincidental thing right off of idle. It certainly makes absolutely NO difference in horsepower or torque.

    Regarding dyno "tuners"... they are clearly misled, unless of course they make a habit of tuning an engine that isn't completely warmed up--which is totally wrong anyway.

    On a side note, I noticed that my Variable Air Intake Valve (the thing on the air filter lid) is ALWAYS open no matter what. It should be closed below 5500 RPM according to the shop manual.

    I tested the vacuum hoses and the solenoid itself, so I know they are all good. I test the diaphragm as well and it works. I checked continuity between the ECU and the two pins in the solenoid connector, and that checked out. Clearly there is a failure somewhere else in the system, so I suppose I will have to get the dealer to check it out.
     
  16. Desblaze

    Desblaze New Member

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    So my take from these findings is it would make a differents in off idle throttle response. I have a stock 06 model and it is annoyingly jumpy coming off idle. Not nice when having to take corners slowly because of slow car drivers in front and its jumping about in a jerky fashion.

    It was so obvious when I first rode my bike I was thinking of getting something else. On the same note I previously owned a 04 VTR1000 and the pairs mod was all the rage there as well. it was even suggested by my local honda mechanic to do it down the track.

    What should I do with my jumpy throttle response off Idle?? do you think a pairs mod will help??
     
  17. junktionfet

    junktionfet New Member

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    Blocking the PAIR valve may very well affect the response off-idle, but I can't say for sure. What's actually happening is the mixture goes from artificially rich to normal as soon as you crack the throttle open. It seems like that would cause a null in the response, but who knows. The ECU is probably mapped to respond a certain way when the throttle is cracked anyway.

    I've heard that adjusting the starter valves (on each throttle body) using the old style procedure will help that notchy throttle response. Apparently Honda now recommends that each starter valve be adjusted to match that of cylinder 4, but the older procedure called for cylinders 1 and 2 to be adjusted differently (I think?). This presumably feeds the cylinders asymmetrically at very small throttle angles, thus making it a little less coarse.
     
  18. OKCVFR

    OKCVFR New Member

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    WINNER! You're one of the few that understand when the PAIR vlaves open and what they do. Congrats, I've been preaching this and know one is listening. There is absolutely no gain in blocking the PAIR valve. And a very minute loss in weight by it's removal.

    Could blocking or removing it make for a smoother throttle, very possible since vaccum is effected, especially off idle. :wink:

    On a secndary note, the ECU will only adjust A/F at open throttle, so when the PAIR valve is open the throttle is closed and the ECU is not utilizing the O2's.

     
  19. yoda6669

    yoda6669 New Member

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    :bounce: :bounce: :bounce: Just completed the pair valve blocking on my VFR. I actually mistaken the vacumm hose for the pair valve hose, I figured that out when checking the 2002 VFR800 service manual. The Hose that goes from the air cleaner to the pair valve is on the left side close to the seat lock, but you still have to raise the tank to work better on it. I used one of my son's marbles to block the hose, and clamp it back in place. easy! :bounce: :bounce: :bounce:

    Check page 3-17 of the service manual for more info.
     
    Last edited: Apr 20, 2008
  20. rdrunner

    rdrunner New Member

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    Hey guys I just got done reading all of your chats and I just want to add to it. I have gutted the cat and I noticed a big improvement right away. I took off the exaust and took it to myfriends shop. You cant screw with oem parts on emmisions bikes. But if I take it off the bike no harm done. Back to my cat. I looked inside and it is not like the old cat. this cat is more like a two steel tubes inside that are welded to the outer housing. So they cut it open on the bottom and gridded the welds then weled the bottom back on. there was no way a crow bar would have gotten that out of there. Besdes all that cat does is heat up the eaxaust that is coming out and try to burn the extra fuel. But the O2 does all the real work and I found that I was able to get reed of the hesitation from 4 to 5 grand at quarter throttle:) I also found that the bike reved faster and had more power. I ran it for a month and then took off my header pipe and found that I had a perfect burn(greyish on vtec side in the valve housing. It really could not get better that that I will be putting on the pair kit for the emission. I also took my bike to the track and found out just by the two brother pipe and k/n And a 15 tooth front gear that I could pull away from my friend with a 748 with pipes ecm mods on the straights. It was the best feeling Thanks for the insight on the chat
     
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