Vtec PAR valve removal???

Like the title says, is it worth pulling all the PAR valve pieces while my bike is apart and if so what are the effects?

Thanks kids! :goofy:

BR

[image: View Post]BaileyRock, on 20 July 2010 - 08:37 PM, said:

Like the title says, is it worth pulling all the PAR valve pieces while my bike is apart and if so what are the effects?

Thanks kids! :goofy:

BR


I can't believe that no one's anwsered your question yet... unless they PM'd you..... But that's not helping the rest of us....

IIRC someone hooked a light up tp the PAIR solanoid and discovered that the only time the PAIR valve was shut, was at idle. In theory it should do bugger all to your performance. It's just there to put fresh air into the exhaust to help burn any unburnt fuel so it will pass the emission tests.

Im sure someone who knows more than me will chime in and correct me. I just ride the damn thing.

The only time the PAIR system allows air into the exhaust is at idle.

It is mainly there to warm up the CAT quickly to reduce emmissions at zero throttle.

If you have no Cat, ie aftermarket headers or removed cat, there isnt much point except it will still aid the combustion of any unburned gases in the exhaust.

If you have your bike dynoed, they will disable the PAIR to stop getting false AFR readings during its operation.

One downside to the PAIR system is it does make the idle exhaust louder due to the combustion which is going on in the exhaust system at idle. this may be an issue if you are running an aftermarket exhaust with no baffles. (like most people).

Personally, I think its just one more piece of emmission control junk that contributes to preventing the bike from being at its best, so on my bike its all gone.

[image: View Post]dogman, on 21 July 2010 - 04:59 AM, said:

The only time the PAIR system allows air into the exhaust is at idle.

It is mainly there to warm up the CAT quickly to reduce emmissions at zero throttle.

If you have no Cat, ie aftermarket headers or removed cat, there isnt much point except it will still aid the combustion of any unburned gases in the exhaust.

If you have your bike dynoed, they will disable the PAIR to stop getting false AFR readings during its operation.

One downside to the PAIR system is it does make the idle exhaust louder due to the combustion which is going on in the exhaust system at idle. this may be an issue if you are running an aftermarket exhaust with no baffles. (like most people).

Personally, I think its just one more piece of emmission control junk that contributes to preventing the bike from being at its best, so on my bike its all gone.



Thanks!
My bike is basicilly all stock except slip-on's and the flapper is plugged. Everything else is still there at 75k.

My mods have almost solely been focused on handling as our VFR's have pleanty of power for solo twisty rippen, not that more power(torque) wouldn't be nice, but that would only improve my wheelies! :cool:

BR

PAIR valve is open at idle and is also open on the overrun (decelerating). Don't believe me? Go for a ride with the solenoid connected, and decelerate (listen to the burbling noise). Then disconect the solenoid and go riding again - no burbling.

Honda Australia themselves were recommending restrictor plates in the PAIR lines for some owners to overcome some fuelling problems caused by PAIR valves.

If you want to tune the bike, disabling them is recommended. Also, if you have an Autotune they're practically a must because otherwise you get completely stuffed O2 readings whenever you're decelerating and at 2% throttle or so.

Hey Kev,
I did some research and there is about 1.21 gigiwatts of horsepower available after disconnecting the valve.
Your welcome.

I've taken the PAIR off my last 2 CBRs and I plan to remove it from my VFR1200 and my CRF250X this winter.

It doesn't do anything for performance but it gets rid of a lot of unneccessary clutter and makes the bike easier to work on.

Question: Does Honda use a standardized unit for street bikes? In other words, are the block-off plates fairly universal? Otherwise it could be tough finding a kit for the 1200.

I blocked off my PAIR valve shortly after getting the VFR and have had no problems to date. One less thing to worry about going bad to appease the CA state emission nazis. You don't need it and it doesn't hurt the VFR in anyway that I know of.

[image: View Post]phobe, on 21 July 2010 - 09:51 AM, said:

I've taken the PAIR off my last 2 CBRs and I plan to remove it from my VFR1200 and my CRF250X this winter.

It doesn't do anything for performance but it gets rid of a lot of unneccessary clutter and makes the bike easier to work on.

Question: Does Honda use a standardized unit for street bikes? In other words, are the block-off plates fairly universal? Otherwise it could be tough finding a kit for the 1200.


All you would need is to measure the opening and get a plate cut to fit. It shouldn't be that hard to do even at home but chances are there will be kits coming out quickly enough.

[image: View Post]tippman, on 21 July 2010 - 09:46 AM, said:

Hey Kev,
I did some research and there is about 1.21 gigiwatts of horsepower available after disconnecting the valve.
Your welcome.

ha, it peaks at 88mph though

I would remove it if I were you, I've taken it off my carb'd bikes and it sounds like the FI versions have the same story (no/slight performance effects, less clutter)
If you're looking for some block off plates I found some Busa emission block off plates work great for the 4th gen, if they changed the spacing all you need is a hacksaw and drill press and some aluminum bar stock to patch up the engine.

[image: View Post]VifferDude, on 21 July 2010 - 12:06 AM, said:

IIRC someone hooked a light up tp the PAIR solanoid and discovered that the only time the PAIR valve was shut, was at idle. In theory it should do bugger all to your performance. It's just there to put fresh air into the exhaust to help burn any unburnt fuel so it will pass the emission tests.

Im sure someone who knows more than me will chime in and correct me. I just ride the damn thing.


There's a lot of misconceptions about the operation of the PAIR. I unplugged the PAIR solenoid and connected a 12v lamp in it's place for a couple weeks on my '06. The lamp would only light when the bike was below 160(ish) degrees and the throttle was closed. Once the bike was up to temp or the throttle was off idle, the solenoid was closed (light off).

It's purpose is to add a little oxygen to the exhaust to help burn left over hydrocarbons. Since the mixture is richer while warming, this would make sense. Burning the extra hydrocarbons while warming, also aids in heating the cat and O2 sensor so they can function properly, sooner. It would seem once warm, the cat does a good enough job without the PAIR. The bike won't go into closed loop until warm, when the PAIR system is not used.

Removing it might extend the time it takes the bike to come up to temp. Removing it also leaves one less thing to go 'bad'. A leaking PAIR could cause a lot of problems in closed loop. I removed mine for that very reason.

[image: View Post]vanion2, on 21 July 2010 - 10:11 AM, said:

I blocked off my PAIR valve shortly after getting the VFR and have had no problems to date. One less thing to worry about going bad to appease the CA state emission nazis. You don't need it and it doesn't hurt the VFR in anyway that I know of.


Results on my 03 VFR800

PAIR Valve with gutted pipe = popping during deceleration
PAIR Valve removed with gutted pipe = no popping during deceleration

I removed the PAIR Valve, sync'd the starter valves, and added the TurboCity High Pressure Fuel Regulater at the same time to eliminate the 4k-5k dead spot and the twitchy throttle.........Not sure which of these cured the problem, but the above stated worked 95% of the time. I later added the power commander to completely eliminate the issues.