Intake Air Control Valve

[btreaves]

Okay fellas...Here's a question for you. I hope you guys can help me out.

About 2 weeks ago I performed some routine maintenance on my 2000 Hayabusa (28,000 miles, changed spark plugs, coolant, etc.). Well in changing the plugs I had to remove the airbox of course and in doing so I noticed that the hose that's suppose to be connected to the "Intake Air Control Valve" wasn't connected. In fact I couldn't even find the hose to reconnect it. I've been riding the bike for many miles and I'm wondering what affect this little hose had on my bikes performance. I mean...The bike still runs hard as poop, but I was reading the service manual and apparently this little hose controls how much air is allowed into the airbox at low to mid range and then from mid range to high range, by operating a little flapper.

I have since taken the bike apart again and I have found the little hose to connect to the "Intake Air Control Valve" and will be putting everything back together tonight.

I also noticed that this same little hose is connected to the "PAIR Valve" which I assume is some kinda emmissions control device (aaaarrrggg).

Anyway, if anyone has any information they can share with me on this please send it along...I'd really appreciate it.

My main question is this, how much of a RWHP loss was I taking with that hose off (I guess I'm really only loosing top end HP) and do I even need that stupid PAIR VALVE (aaarrrggg!)

Thanks in advance for any information you can provide on the subject!

This is a great site!

 

[Johnnycheese]

Which hose the one to the flapper valve?

Plug the Pair of and save weight
Reaper has the kits

 

[SierraFlyer]

I agree, take off the PAIR. It is used to pump air into the exhaust manifold to help burn off emissions. What it really does is cause backfires and may damage the engine (It WILL scare old ladies to death). Get "Block-off plates" from any Busa performance shop. Muzzy, Shnitz, hayabusazone.com, etc. No more decell explosions. It saves 2 pounds+.

The flapper hose you are going to reconnect is not worth much in my opinion. Yours was disconnected so the flapper was in the full open position. Good for high end and supposedly bad for low end. The other thing you had was a bad vaccuum leak. That would hurt high end and low end and idle quality too. Plug the tube without reconnecting the flapper first to see what improvements you get then hook up the flapper and see if that makes a difference? I cut my flap out completely and diconnected the line.

 

[btreaves]

Wow Sierra,

You are a wealth of information. I reconnected the vacuum hose last night and took the bike out and it ran much better than it has in the past. What you said about a bad vacuum leak must have been true, because the bike pulls my harder and much quicker...It really feels much better now that the flapper valve is hooked back up. I wonder how much that was hurting my hp.

I don't know why, but I thought that the flapper was in the full closed position with that hose disconnected, but I guess I was wrong. I was thinking that my baby wasn't getting enough air at high speeds and high rpm, but either way it wasn't getting what it was suppose to get.

I like to keep my bikes completely stock. That way when I beat riders in my area with souped up bikes they can't say anything but, "damn...I lost to a stock bike with a better rider". I'd much rather work on my riding skills than spend money on my bike.

I'm gonna do what you said though about blocking off that flapper hose...I have a buddy with a dyno and we're gonna do some tests to see what works best...Should be interesting. I'm also gonna see if this BMC filter is worth the price.

Thanks for the information...I really appreciate it. Keep it coming. You have a great attitude.

 

[SierraFlyer]

I bought the BMC race filter based on what I read here on the boards. The race filter has deeper pleats that allow more air to flow. others have done a side by side with K/N and the non race BMC. The BMC race made the most HP. I don't know if they re-tuned between filters though.

 

[SierraFlyer]

I bought the BMC race filter based on what I read here on the boards. The race filter has deeper pleats that allow more air to flow. others have done a side by side with K/N and the non race BMC. The BMC race made the most HP. I don't know if they re-tuned between filters though.

I have been wrenching on the Busa since I got it. I had the same problems as you are finding. Once you do a few things to the bike it really is not that hard to figure out the problems. It is not as complicated as it looks.

 

[SierraFlyer]

I bought the BMC race filter based on what I read here on the boards. The race filter has deeper pleats that allow more air to flow. others have done a side by side with K/N and the non race BMC. The BMC race made the most HP. I don't know if they re-tuned between filters though.

I have been wrenching on the Busa since I got it. I had the same problems as you are finding. Once you do a few things to the bike it really is not that hard to figure out the problems. It is not as complicated as it looks.

 

[SierraFlyer]

I bought the BMC race filter based on what I read here on the boards. The race filter has deeper pleats that allow more air to flow. others have done a side by side with K/N and the non race BMC. The BMC race made the most HP. I don't know if they re-tuned between filters though.

I have been wrenching on the Busa since I got it. I had the same problems as you are finding. Once you do a few things to the bike it really is not that hard to figure out the problems. It is not as complicated as it looks.

 

[SierraFlyer]

Sorry about the multiple posts, It said I had an error and I reposted a couple of times. It must have been getting through anyway.