Air Box Part/Mod From Wild Hair

I found this air box part/mod from Wild Hair, while looking for FJR parts on there site. Its kind of the mod that I had already done, except that theres is chrome, and well on my mine, just cut the inside tube from where it goes to the air filter, and took off the snokal, theres is much smoother looking. The outside cover still goes on, as does the body pannel. I know I have read all the post about the air box, and no ones seems to have anything good to say about modding it, but on my 2005, with just the slip ons, and my version of this change, the bike runs out so much smoother and quicker. Oh well, I have a picture from there web site of the part, I just cant seem to figure out how to post it, any one want to help?

Sean

I took the airbox snorkel off my '05 FJR and it does seem to run smoother also.

you mean this from WH?

FJRMGM said:

I took the airbox snorkel off my '05 FJR and it does seem to run smoother also.
you mean this from WH?

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Thats the one, thank you!!!!

And yes, my bike revs smoother, runs smoother, and pulls a fair deal harder than it did before..

No offesense, but I am EXTREMELY skeptical of butt dynos. Where's the before and after dyno results? And how does an engine 'rev smoother'?

In the early days, back in 03 or so, BikeJohnny did extensive testing (with dynos) to try and develop a new and improved intake for the FJR and couldn't.

I too read all the comments, but what I found interesting is that only 1/2 of my air filter would get dirty before removing the snorkel. I really haven't noticed any performance/smoothness gains, but I'm only using part of the bikes capibilities anyway.

I do think its louder now.

the air horn is only there to reduce intake noise anyway..

Intake systems are developed on a flow bench. Screwing with air delivery changes the way intake air is metered. Unless you re-flow the intake system after a modification and change the corresponding table or function that the ECU uses for air:fuel delivery, 9 times out of 10 the results are not positive. This of course applies to only FI. The same principles apply in carburated systems, but the A/F ratio is controlled differently, of course.

In short: don't **** with it.

Also: Air filters with oiled media are bad, and should be avoided.

SkooterG said:

No offesense, but I am EXTREMELY skeptical of butt dynos. Where's the before and after dyno results? And how does an engine 'rev smoother'?
In the early days, back in 03 or so, BikeJohnny did extensive testing (with dynos) to try and develop a new and improved intake for the FJR and couldn't.

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To me smoother is when the motor feels like its breathing better, or easier. So theres more of a willingness to rev.When theres a restricktion on the motor, theres usually a caorseness that you can feel/hear..I know this sounds crazy, but becuase of being a studio engineer/producer my ears/fingers/body tend to pick up on little vibs and noises more than most poeple do, which has a habbit of driving me up the wall...

ngarider said:

Intake systems are developed on a flow bench. Screwing with air delivery changes the way intake air is metered. Unless you re-flow the intake system after a modification and change the corresponding table or function that the ECU uses for air:fuel delivery, 9 times out of 10 the results are not positive. This of course applies to only FI. The same principles apply in carburated systems, but the A/F ratio is controlled differently, of course.
In short: don't **** with it.

Also: Air filters with oiled media are bad, and should be avoided.

Click to expand...

Isnt this mostly true on a pressurised air box? The air box for the FJR is just a place for air to enter the fiter, and the to the "stacks" into the TBs.. Since theres no ram-air on the FJR, the box isnt pressurised. Like the stock box on my CX-7, it was a big restriction, but add a cold air intake, remove the box, and the motor breather much, much better. Im not doubting that there was a lot of dyno work done to see if there was a better way/design for the air box. I have read the post, and seen the results. Im just saying, removing the snorkel, and the little pipe that goes into the air filter, really seems to make some differance. Not to mention, you get to hear the air box a bot more, which is a neat sound...

Sean

leo said:

I do think its louder now.

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Louder means faster, right?

ngarider said:

Intake systems are developed on a flow bench. Screwing with air delivery changes the way intake air is metered. Unless you re-flow the intake system after a modification and change the corresponding table or function that the ECU uses for air:fuel delivery, 9 times out of 10 the results are not positive. This of course applies to only FI. The same principles apply in carburated systems, but the A/F ratio is controlled differently, of course.
In short: don't **** with it.

Also: Air filters with oiled media are bad, and should be avoided.

Click to expand...

...but as already mentioned, if an intake system is designed to reduce noise, as all modern intake systems are, there is usually some room for improvement.

I never put the bike on the dyno either before or after taking off the snorkel but I'd venture to guess I picked up a good twenty HP by doing this mod.

And the oiled Uni-Filter just made it work that much better.

As for this - B.S. on both counts:

Intake systems are developed on a flow bench. Screwing with air delivery changes the way intake air is metered. Unless you re-flow the intake system after a modification and change the corresponding table or function that the ECU uses for air:fuel delivery, 9 times out of 10 the results are not positive. This of course applies to only FI. The same principles apply in carburated systems, but the A/F ratio is controlled differently, of course.

In short: don't **** with it.

Also: Air filters with oiled media are bad, and should be avoided.

MAJ Todd said:

ngarider said:

Intake systems are developed on a flow bench. Screwing with air delivery changes the way intake air is metered. Unless you re-flow the intake system after a modification and change the corresponding table or function that the ECU uses for air:fuel delivery, 9 times out of 10 the results are not positive. This of course applies to only FI. The same principles apply in carburated systems, but the A/F ratio is controlled differently, of course.
In short: don't **** with it.

Also: Air filters with oiled media are bad, and should be avoided.

Click to expand...

...but as already mentioned, if an intake system is designed to reduce noise, as all modern intake systems are, there is usually some room for improvement.

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The intake, cylinder head, header and exhaust are designed as a tuned system. Motorcycle systems are highly tuned for volumetric efficiency, with a sport/tourer typically tuned for low rpm and high rpm resonance points.

Even if you do manage to make a change to a resonance point in the system for an improvement, VE says that you have to give up something at another rpm range. Opening up an induction system for high end breathing will cost low rpm power. Where do you normally spend your riding time? Easier breathing does not have any affect on the engine at low or mid range power settings. If you are saying that the engine is smoother when the throttle is snapped open, well, that is a high range setting, no? If the engine is now inducting more air because of the filter mod, how is the extra air getting out the stock exhaust which is tuned for the stock air flow?

Ya know, I'd be willing to bet that this has been discussed here before :lol:

Edited: It does look like the chrome doohickey will make air filter changes much easier and perhaps makes the air filter a less inviting place for rodents during storage.

kawwikid said:

Isnt this mostly true on a pressurised air box? The air box for the FJR is just a place for air to enter the fiter, and the to the "stacks" into the TBs.. Since theres no ram-air on the FJR, the box isnt pressurised.

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Sure it is. All air boxes are pressurized.

The inlet to the Yamaha FJR airbox is nominally pressurized to 100kPa (~14.5 psi). aka atmospheric pressure. :blink:

Without that pressure there would be no airflow into the engine.

But I'm sure you meant pressurized above atmospheric, as in boost. The pressure in the box should not be of any significance. What would be of importance is what the flow rate through the box is and what resistance the box and filter presents to that flow.

:sarcasm:

FJRMGM said:

I never put the bike on the dyno either before or after taking off the snorkel but I'd venture to guess I picked up a good twenty HP by doing this mod.
And the oiled Uni-Filter just made it work that much better.

As for this - B.S. on both counts:

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:rofl:

Bike Effects said:

leo said:

I do think its louder now.

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Louder means faster, right?

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Louder means safer! "Loud boxes save lives"

Air inlet systems generally get a lot of development time to accomplish the correct flow, tuning and volumes for maximum flow and minimum noise. There are pass-by noise requirements for motorcycles and loud induction honking is part of the equation of meeting passby requirements.

Certainly flow bench work is one way to quantify and develop an air induction system but it is not the definitive way. Flow benches have a very hard time replicating the dynamics of an air induction system with alternate flow paths from different cylinders firing in sequence, the reversal of flow inside the air box, reversion from cam overlap and the firing frequency changing as the RPM changes.

Hard to imagine bolting on an air induction piece and gaining 20 HP on any engine much less an FJR with 1300 cc's. I know Yamaha stubs their toe occasionally but I'd be willing to bet that the FJR airbox is better than that.

In the automotive area we get GREAT amusement out of the "cold air tubes" and "air box" eliminators that are marketed with huge power gains claimed. On OUR dynos they rarely work as well as the production systems and most cause loss in power despite the huge tubes, huge aircleaners and dramatic increase in induction noise. I have no reason to think that systems/mods like that for the FJR are any different.

With the inner tube of the air inlet removed and the cover removed (as in the picture) there will certainly be more induction roar and if you are after that sound then the mods are for you. Loud induction, however, is absolutely NO guarantee of more power. Usually just the opposite.

Changing the flow characteristics, reversion, positive tuning effects, etc. of the air box can also screw up the sensor readings for the Fuel injection system causing large errors in spark and fuel delivery. Not necessarily will this happen but it is certainly possible and often seen. Whether it causes you are the engine a problem (like a meltdown) is open for discussion but it will likely effect it to some extent.

When an engine is at full throttle or wide open throttle the "pressure" in the inlet track should be equal to atmospheric pressure (assuming no real "tuning" is taking place or ram air is present) or the vacuum reading should be zero. This makes it pretty easy to evaluate if an air induction system is making any difference in restriction (which is always the claim.) Run a vacuum line from a vacuum tap as close to the intake port as is possible, hook it to a very accurate vacuum gauge (a magnehelic gauge that will reads tenths of an inch of mercury is best.) Next, run the engine at full throttle/full load/max RPM (just revving it in neutral will NOT do, you have to load it) with the production air intake assembly and record the vacuum reading. Install the "mod'ed" system and rerun the same test. If you see a reduction in vacuum reading then there is a slight possibility that the mod will make more power....at least it will tend to show if there is really a reduction in pressure drop across the system with the mod. Take the time to do this and you will find that many of the classic mods for induction systems just do not work because they do not reduce the restriction. Period.

Trying to develop a better "tuned" system can take months and months and you need an accurate engine dyno and controlled air temp and pressure. Even significant changes in pressure drop and tuning can hardly make 3 or 5 HP on a 400 Hp engine much less 20. Been there, done that. Period. Even significant amounts of ram air (where you can actually measure an increase above atmospheric inside the air box) do not give nearly that much power.

I am personally aware of one case where a port fuel injected artic cat snowmobile engine (it uses a speed density system just like the FJR) would run perfectly fine in stock condition and would foul plugs and run poorly at part throttle with an aftermarket pipe and air box modification. On the flow bench both parts worked well and were an "improvement" but on the running engine the pressure pulses in the inlet system changed and wreaked havoc on the MAP sensor reading causing errors in sparking and fueling. The parts made "more power" at the peak power point but made the sled unrideable because of the negative effect on the sensor readings at lower RPM. Funny thing is that the exact same parts made the carbureted version of the engine run much better. Proof that there are gremlins waiting to bite you with the fuel injection system if you are not carefull.

Wow jestal, you learned me sumptin and I'm not interested in modding my airbox.

worldbound4now said:

Wow jestal, you learned me sumptin and I'm not interested in modding my airbox.

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Yeah -- he almost always learns me something when he's talking about engines.