Hi all sorry if there's a topic about this already but i havnt found it if there is
What are the benifits of removing the pair system
i've found lots of information on doing it just not the reason for it
thanks in advance
on the 6th gens, it seems to help with the 4-5k rpm flat spot and snatchiness of the throttle. sometimes it takes removing the 02 sensor as well to get it where you like it.
Hi all sorry if there's a topic about this already but i havnt found it if there is
What are the benifits of removing the pair system
i've found lots of information on doing it just not the reason for it
thanks in advance
on the 6th gens, it seems to help with the 4-5k rpm flat spot and snatchiness of the throttle. sometimes it takes removing the 02 sensor as well to get it where you like it.
I haven't heard of any real added power benefits to removing the PAIR system on 3rd and 4th gen bikes. I think it's mostly done to rget rid of weight and also make it easier to service the bike without all that plumbing in the way, like replacing thermostats. You do have to do it correctly so that you do not affect the bikes stock performance. Leaving some of the hoses and apertures open after removing the equipment can make for a non-happy running VFR.
I remember someone weighing the PAIR equipment that he took of his bike some time ago, and it all weighed about 3 pounds. That's about the weight of a moderately loaded up tank bag. I doubt if you can detect any significant gas savings with that little weight off. The PAIR system was meant mostly as an anti-pollution device that teams up with the gas vapor recovery system (the charcoal canister linked to your sealed gas tank) to prevent any unburnt gasoline vaoprs from getting into the atmosphere. The PAIR system introduces (injects) additional oxygen at the base of the headers as they come out of the motor to extend combustion in the exhaust system as they get out of the cylinders. some might think that there might be a scavenging effect brought on by this, because of maybe higher exhaust pulse velocities that might result from the extended burn and higher manifold temps, but I doubt if it is enough to be realized as any additonal power or gas savings.
No. All I have left on my 6th gen is the cat. Removing the charcoal canister makes oil changes much easier. Our little bikes arent going to ruin the enviroment with all the polllution devices disabled.
Eliminates the "thwak" noise when you open and close the throttle.
Eliminates the popping, afterfiring noise, which is especially noticeable with an aftermarket slip on.
Well, I found the bike ran worse after PAIR valve removal: the idle speed dropped 300 rpm or so, and it seemed a bit more gutless. It did seem to have a bit more of a kick when cracking the throttle open, which doesn't make any sense, unless it was because it was running worse up to about 4k rpm.
I reconnected it when I read that the CatCon could be wrecked by disabling the PAIR system. With the Gubmint tightening up on noise and emissions here, I thought I'd leave it connected.
The pair system is one that does what it does POST combustion. It does not affect the air fuel mixture as the air fuel mix has already exploded before the pair syatem injects air into the POST valve exhaust.
This came up in Formula USA on a protest. The results were a 0.0 horsepower gain.
I removed the pair valve and synced the 'start valves' on the same day.... totally fixed my 4-5K surging problems. I had already had O2 elims from the start, but still had the problem. And I'm thinking that it was the pair valve mostly. Too bad we did the start valves at the same time adding one more variable.
Well, I found the bike ran worse after PAIR valve removal: the idle speed dropped 300 rpm or so, and it seemed a bit more gutless. It did seem to have a bit more of a kick when cracking the throttle open, which doesn't make any sense, unless it was because it was running worse up to about 4k rpm. I reconnected it when I read that the CatCon could be wrecked by disabling the PAIR system. With the Gubmint tightening up on noise and emissions here, I thought I'd leave it connected.
did you block off all the fittings? did one or more fall out? if you dont plug up the holes after removel it will screw things up.
The pair system is one that does what it does POST combustion. It does not affect the air fuel mixture as the air fuel mix has already exploded before the pair syatem injects air into the POST valve exhaust.
This came up in Formula USA on a protest. The results were a 0.0 horsepower gain.
using this as logic.. then an after market pipe does nothing too.
all we all know that is crap.any change in the exhaust pipe will have efect on power.
The pair system is one that does what it does POST combustion. It does not affect the air fuel mixture as the air fuel mix has already exploded before the pair syatem injects air into the POST valve exhaust.
This came up in Formula USA on a protest. The results were a 0.0 horsepower gain.
AAAAAAAAAhhh. Thank you. I see. Thank you for your help.
The pair system is one that does what it does POST combustion. It does not affect the air fuel mixture as the air fuel mix has already exploded before the pair syatem injects air into the POST valve exhaust.
This came up in Formula USA on a protest. The results were a 0.0 horsepower gain.
using this as logic.. then an after market pipe does nothing too.
all we all know that is crap.any change in the exhaust pipe will have efect on power.
You would have to show that the miniscule (by volume) amount of injected atmospheric air into the exhaust gasses was somehow effecting the reflected power pulses. I suspect it has zero effect on cylinder mixture (power). But, I would happily look at any evidence you could present.
A more free flowing exhaust system can indeed effect reflected power pulses (the "negative" wave) and thus can have an effect on cylinder mixture (power).
Comparing apples and oranges does not constitute logic.
OK, so if one wants to remove the pair valve system,lets say to simplify the area where it resides and to remove some weight,what does one have to do in order to counteract its removal so we dont make the engine loose power or hurt its throttle response? eddie
On the 3rd and 4th gens, plug a vacuum cap on the carbs X 2, use block off plates above exhaust headers X 4, and plug the two holes on the forward part of the airbox. That's all I did and I haven' had any problems yet(knock on wood). If you don't block off the two nipples on the carb/manifold you will end up with a vacuum leak, which causes the crappy running. Good luck!
End of thread · 19 posts recoveredWayback Machine snapshot 17 Oct 2015