Air Induction system removal?

[troyw]

Hey guys n' gals,

I noticed a thread on the FZ1 forums about Ivan's air induction system removal. On my Honda VTX 1800, we called it "desmogging". Is this the same thing on the FZ6? Is this system hampering the motor in any way, and should it be taken off?

- Troy

 

[SovietRobot]

There's really only 3 reasons you should remove it on the FZ6

1. Getting the bike dynotuned, it'll give you a better A/F ratio reading
2. If you have a lot of popping on decel, even after syncing the throttlebodies
3. If you have already removed the cat, you should do this too

It's not as bad as it is on the metric cruisers

 

[troyw]

Ok, yeah, I removed the mid-pipe cat. The ones in the header we can't do anything about, at least as far as I can tell. So, how is this done? It was pretty straightforward on the VTX, but required two block off plates and a LOT of patience...and small hands like mine. Ok, it wasn't that easy......but it's really just time consuming.

Thanks!
Troy

 

[Hellgate]

I guess my question is why? Air induction is a good thing and has no negative impact on the bikes performance. All AI does in introduce fresh air into the exhaust system to help the fuel completely burn before going out the exhaust.

 

[SovietRobot]

Without the cat, the exhaust system usually doesn't get hot enough to make real use of the AIS system, and all that extra air and fuel coming out during the exhaust stroke can give you that lumpy idle

I would remove it if I removed my cat converter.

To the OP, the cheap way of doing it is taking the elbows off, flipping the inside valves around, then putting them back on, effectively "blocking" the air from entering the combustion chambers.
The "right" way to do it is to completely remove the AIS equipment(valve, hoses, elbows) and use block off plates on top of the valve cover.

 

[gt89stang393]

These were linked on another site, I will share. One is for removal and the other is to turn the AIS into what I call a pan evac or pulling crankcase pressure from the valve cover. These are both on older R6's. I plan on doing this mod when I do BD's headlight mod.

How-to: Crank Case Breather Modification : Yamaha R6 Forum: R6MessageNet : YZF-R6 Forums

How-to: completely remove AIS : Yamaha R6 Forum: R6MessageNet : YZF-R6 Forums

 

[troyw]

As when the VTX was modded with new intake, exhaust, etc., the air induction became a problem. Not a major one at all, but just annoying with the popping and stuff. Getting rid of it solved that. It's not a horsepower mod, but it does get rid of extra plumbing and mess. I guess it's the same on this bike too. I'll try to find some block off plates and do it right like I did on the other bike. Oh, and it does have a lumpier idle now when cold not that the cat's gone...

- T.

 

[Hellgate]

Hummm...seems to me what is needed is a Power Commander and a proper dyno tune to make all of the changes work in concert.

 

[troyw]

Yep...you would be correct sir!

- T.

 

[SovietRobot]

A power commander, tb sync, dyno tune, in addition to the AIS removal
You will be so happy with the results.

 

[ddg]

By the sounds of this thread since I have Leo's w/cat elim, power commander, and K&N and will be getting the bike dyno tuned I should remove the AIS. I have a lumpy idle now but will be doing the sync shortly. Looks like my riding start just got pushed back because I woke up to more snow, urgh.

 

[ddg]

After spending time researching the AIS, mine has gotta go. The link on the R6 removal was great. Next week I have some time planned to do bike work so I will try to take pictures and do a how-to. I will be doing the snyc at the same time so I'll try to do a write up/pics on that as well.

 

[Wildcard]

Lots of good info here. I have removed my cat pipe and there is lots of popping on deaccel (sounds wicked though) and even after re-synching tb's still have lopey idle. So maybe I'll do this as well.

 

[someone08]

my bother did this for his honda xr650l and it turned into a mess because of something that happend to the carb, but these problems were due to aftermarket jets and other things. after this i would have to say do this at your own risk, because really if it isnt broke dont fix it, but if you want to do it then good luck and i will be happy to see the results. thats my 2 cents.

 

[ddg]

The popping on decel is a bit cool but the deciding factor for me was inaccurate dyno tuning. If I am spending the money and taking the trouble get make sure I get the proper mixture in the engine and the AIS is going to screw the readings up, I'll get rid of it. The lumpy idle almost caused me to drop the bike once as well. I was making a slow speed turn with the bike tipped over and without the constant forward thrust it almost ended up bad.

 

[Fred]

The popping on decel is a bit cool but the deciding factor for me was inaccurate dyno tuning. If I am spending the money and taking the trouble get make sure I get the proper mixture in the engine and the AIS is going to screw the readings up, I'll get rid of it.

AIS only works at idle and during warmup. (Service manual, chapter 7, page 12)

So it won't affect your dyno tuning. Think about it a minute. These bikes have O2 sensors. If the AIS was functioning when the bike was operating in closed loop mode, it would never run right.

The only effect you'll see from removing the AIS is more smog in the air.

Fred

 

[Hellgate]

AIS only works at idle and during warmup. (Service manual, chapter 7, page 12)

So it won't affect your dyno tuning. Think about it a minute. These bikes have O2 sensors. If the AIS was functioning when the bike was operating in closed loop mode, it would never run right.

The only effect you'll see from removing the AIS is more smog in the air.

Fred

Fred hit the nail on the head.

These days "smog" equipment doesn't hurt the performance of your bike. The technology is first rate and the whole package works as a complete system. The CATs that Yamaha uses are some of the best in the business as far as keeping the air clean and not impacting the performance of your bike.

About 10+ years ago European Car magazine took a VW GTI and put on a CAT by pass pipe and then dynoed it. It made LESS HP and less torque with the by pass pipe, that is how good the VW CATs are, really any CAT sold today.

 

[coursonap]

If you want to do this mod here is what needs to be removed, and under the caps the reeds need to be flipped to block off any air.

 

[Fred]

If you want to do this mod here is what needs to be removed, and under the caps the reeds need to be flipped to block off any air.

Yes, and after you turn the reed valves around, the bike's exhaust will be flowing into the airbox during closed throttle and warmup.

Fred

 

[ddg]

This is turning into quite a topic:sinister: With a stock bike I don't think anyone would remove the AIS, as it is designed to work with the full exhaust from the factory. However with an aftermarket exhaust with a cat elim pipe things are changed slightly. I read the service manual and the thing that got left out in the post was the, "Ordinarily" it only allows air flow at idle". Right above that in the service manual it explains the AIS working as "When there is negative pressure at the exhaust port, the reed valve opens, allowing secondary air to flow into the exhaust port." Which I assume mean on decel. The popping that you hear, by all that I read, is caused by the AIS, which is not during idle. So all that popping is unburned exhaust gases finally having their chance to ignite without providing any engine power . I bike tuned on a dyno w/out the AIS would have a more correct air/fuel ratio which results in less unburned gases which would probably reduce fuel consumption and make less pollutants. I know this is not as efficent as the AIS setup with full cats but I have long ago decided to run an aftermarket exhaust and the cat has been removed. As a side note, when you reverse the reed valves you place a hose cap around the hole and clamp it so no exhaust gases are getting into your airbox. All my thoughts on this may be wrong but as of now I am still going though with the mod. Looking forward to responses. Just my 3 cents!!