VFR800 PAIR mod, snorkel, flapper questions

I know I've been asking a lot of questions lately, but I love the bike and want to keep it for a long time and these are some things I feel I must do to make the bike more manageable.

My bike is a 2003 VFR800

First off, I am experiencing that really weird throttle response below 6,000 RPM. There is a flat spot at that 5k rpm mark as well, and below that it's just really weird. Above the 6k and especially during VTEC the bike behaves properly though.

So anyway... I want to do the PAIR, Snorkel, and Flapper mods. My only questions are really regarding the PAIR system... I heard people say that you can disconnect the wire and just leave it unplugged, but others said that causes the PAIR system to constantly be letting air into the exhaust and that it's better to block it?? I don't know what the truth is though, hopefully someone can help me.

Also I was considering doing an o2 eliminator, but didn't know where I could get one and what the pros and cons to doing that is? I don't plan on installing a power commander so maybe I should forget about that.


A final side note, after doing lots of lurking I noticed that most people who seem to love these mods have the older model bikes (like 02-05) and the people who say that it isn't worth it are those with (06+) newer models... I wonder if honda changed something to correct it? Either way the way they have it right now isn't preferable.

 

On my '07 RWB, I have done the PAIR mod by installing the block-off plates, removed the snorkel, and installed a PC-V, which disconnects the O2 sensors. I left the Flapper active. The throttle response at lower revs is much more responsive with the flapper active than disconnected.

 

I have an 07 as well. The fueling was pretty horrible stock. I first did the easy free stuff, like the pair/snorkel/flapper, which I guess helped a bit, maybe just placebo from extra intake noise and a more accurate 02 sensor reading from blocking the pair valves. Then I deleted the 02 sensors (330 ohm resistors), and this made a decent difference in the steady throttle fueling (no more in and out of open/closed fuel injection), but the vtec transition was still rough. So next I did the normal bolt ons (catless headers, slip-on, airfilter etc) and installed a power commander. It was better with the default map and even better further after getting a custom dyno tune. I later went with Rapid bike and individually tuned each cylinder plus ignition mapping, which was a million times better than a power commander could ever dream of, but a power commander plus custom tune is pretty good.

 

As far as how to do all this, dude there are a million threads. Get acquainted with the search button...

 

I've been reading all day and everyone just keeps contradicting each other... which I guess makes sense...

I'm really only concerned with the PAIR mod, people are saying that if you disconnect the wire it will make the PAIR system constantly pump air into the exhaust which will make it worse and that you should plug it... yet, other places are saying the opposite... so i'm just completely lost. What is the correct answer?? I guess you already answered my other question in regards to the o2 sensor block off. I was planing on blocking it off but again, some people were saying that you needed a PCV in order to block it off or its pointless... idk. I guess i'll just do them and give my personal opinions.

 

In the 5G service manual it states that the PAIR solenoid is open by default (i.e. no signal from the ECM), and closes when there is a signal from the ECM. So if the signal wire is disconnected, no signal, solenoid is open and air can enter the PAIR pipework and thence to the exhaust header.

To me one of the benefits of PAIR elimination is the removal of a whole lot of hoses and cables, so I disconnected and removed the solenoid valve and all the hoses. Then I capped the vacuum port at the airbox, and used blanking plates to seal off at the cam covers. You can get the same effect (stopping air entering the exhaust) by sticking a marble in the vacuum hose and leave all the rest in place.

 

You can easily test the PAIR solenoid valve yourself. Disconnect the hose going to the solenoid from the air cleaner housing and gently blow into it. If you manage to blow air through it the valve is open. My PAIR solenoid valve was open with the wire disconnected, but I have since started to believe it is broken.

The Honda service manual for the 6th gen says that there should NOT flow any air through the valve unless 12V is connected. But maybe the manual is wrong. Best bet is just to check for yourself.

My bike was modded with the wire unplugged when I got it, but on my bike that meant that the valve was open and the PAIR valves constantly supplied fresh air into the exhaust. I have not tested to see if the solenoid closes if I apply 12V to it, I just disconnected the whole thing and mounted silicone caps on the PAIR inlets.
https://www.do88.se/en/artiklar/siliconecap-12mm-black.html

Block off plates are cleaner, but also more expensive and I have read that some people got bent plates that where hard to get to seal correctly.

 

Update.

So I went to do the "mods" and as I was doing the snorkel mod I found a ton of leaves inside the airbox... probably mice or something... although I didn't see any droppings.

Anyway... I vacuumed it all up and it was a K&N filter so luckily I had the cleaning and oil kit so I gave that all a good cleaning.

So I chucked the snorkel out and disconnected and zip tied off the vacuum for the flapper then I disconnected the PAIR plugs and electrical taped them and in addition I also blocked off the hose with a toothpaste cap just in case.


Anyway my conclusions with everything is that the bike is definitely smoothed out, especially on the lower end it did exactly what I hoped it would do. Is it perfect? No i'll probably need a PCV to make it perfect but it's pretty damn good, no longer a complaint...

Too bad I will never know if my issues were the PAIR, Flapper, & Snorkel. Or if it was the blocked filter, or a combination of the two.

 

You should have done the o2 sensors too.

 

Huh... i'll do them next. Something like this will work, right? https://www.ebay.com/p/?iid=331725306627&&&chn=ps

I don't trust in my ability to make my own... also there are 2 correct?

If so, i'll order those tonight and do that next!

 

Yup you will need 2. This will really smooth out the part throttle cruising.