Air Box Mod?

AML

AML

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Just a quick question for a noobie,

What exactly does it do to the bike?

I realize it allows for more air to come into the bike, so is this for extra power?

Does it also help with cooling?
 
Allows the bike to breathe MUCH better. Stock the engine is trying to run while breathing threw a straw. I cut my air box up pretty good and was shocked at the power gains. It may be just me but I saw more improvement from the airbox mod than I did from a slip on and gutting the cat.

Here are my before and after pics

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supersonic said:
The obvious question is. Why would Yamaha build in such a flaw?
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They wouldn't!

I was speaking to my dyno guy about this when I was at his shop last week. In his experience, cutting airboxes only makes the bike sound louder/faster. This is the second dyno guy I've spoke to, both about FZ1's and both told me the same thing.

My thoughts are that Yamaha pay someone tens of thousands of pounds/dollars a year to design these airboxes, they're very well qualified and use all manner of flow meters and other high-tech stuff to design the airbox to suit the bike over all speeds and at all temperatures.
I really don't believe that someone just hacking random parts of the airbox off to 'improve' it really does improve it!
 
Rusty said:
They wouldn't!

I was speaking to my dyno guy about this when I was at his shop last week. In his experience, cutting airboxes only makes the bike sound louder/faster. This is the second dyno guy I've spoke to, both about FZ1's and both told me the same thing.

My thoughts are that Yamaha pay someone tens of thousands of pounds/dollars a year to design these airboxes, they're very well qualified and use all manner of flow meters and other high-tech stuff to design the airbox to suit the bike over all speeds and at all temperatures.
I really don't believe that someone just hacking random parts of the airbox off to 'improve' it really does improve it!
Click to expand...

I agree but i chopped mine anyway, the bike has a nice growl it is worth doing for that.
 
Rusty said:
They wouldn't!

I was speaking to my dyno guy about this when I was at his shop last week. In his experience, cutting airboxes only makes the bike sound louder/faster. This is the second dyno guy I've spoke to, both about FZ1's and both told me the same thing.

My thoughts are that Yamaha pay someone tens of thousands of pounds/dollars a year to design these airboxes, they're very well qualified and use all manner of flow meters and other high-tech stuff to design the airbox to suit the bike over all speeds and at all temperatures.
I really don't believe that someone just hacking random parts of the airbox off to 'improve' it really does improve it!
Click to expand...
This is what is causing me to hold off on the mod. I find it hard to beleive a company with such a history in motorcycle building and development could make such a blunder on the airbox!
Now on the other hand, I have a Micron exhaust fitted to my FZ1. Which MAY require extra air intake?
 
well if you guys have it right K&N has been committing fraud for years---but I don't think so

Opening the airbox and opening the exhaust is a clear way to increase power

Look at Ivan's dyno's

The stock bike is restricted everywhere for emissions and noise standards
 
The stock airbox snorkle is designed for noise control, not maximum power.

I'd be worried about anyone who works at a dyno and thinks stock air boxes are designed to flow all the air needed for a modified engine.

Basicly, all Internal Combustion engines are just air pumps. How much air can you pump so you can burn fuel. (The ratio depends on the fuel used, and the demands of the engine at any given moment.)

The FZ1 in the R1 aplication has a larger air filter opening, and filter. Both contribute to better flow, and thus, the R1 is rated at producing more power.

When you open up the airbox on any stock design, you improve flow within the bounds of the airbox volume, and filter size/area.

Clearly, the snorkle hole on the FZ1 stock box is smaller than the filter area. The filter media can be improved on as well. (Decreased resistance to flow.)

There are many dyno sheets showing the gains of improving flow on this engine. Sure the cams are not the same, static compression ratio is slightly higher and the crank is weighted for tourqe down low v/s high end power and fast RPM changes, but it's the same basic engine that makes 150hp at the rear wheel in the R1, and will make close to that in FZ1 application with the intake and exhaust restrictions minimalized.

So, the dyno guys don't think an improvement from around 125rwhp stock, to over 145rwhp is due to air box changes? LOL (Yes, the slip on/header has part of the job as well, but both combine to improve flow through the motor by reducing restrictions to get the air in, and exhaust out.)

And it's not just peak power either, you improve on the power everywhere it's used with these mods. I see no downside, unless you really don't like a bike that makes any more noise than stock. (Sure, there are many versions of opening up the air box too. Look at what Dale Walker reccomends, just a few extra holes.. Lars has the snorkle cut off, and both have improved power figures to show the mods add power.)

I suppose if you just wanted to keep most of the noise control, try Dale's mod, and go from there.

I'm actually replacing my de-screened stock filter with a Pipercross one, and will take the Lars mod another step further, as I think there is air to be gained with Dale's side hole idea. Look at how the airbox sits in the frame. And then look at where the air has to flow from to get into the box. I think opening up those paths can't hurt flow, and I don't mind the noise. :)
 
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Ok I will add my :2cents: to this discussion...

The way Ivan explained it to me was that the opening of the stock airbox was big enough to support the engine's level of HP power. However, because the way the air comes in to the airbox and has to turn you tend to lose velocity and therefore the amount of air that enters is somewhat limited by this. By opening the airbox you alleviate this condition a bit and it results in more power.

As those that have done the airbox mod can attest to there is a significant increase in intake noise. I think that Yamaha thought (correctly) that the majority of riders wouldn't want this additional noise and so the airbox was designed to support a certain level of HP while reducing noise. Everything that the OE manufactures do is a compromise of some sort, be it for noise, emissions or fuel economy.

For those of us that don't mind, and actually enjoy, the extra noise mod away :D
 
the stock air box as well as the entire bike is a compromise. The air box is designed to work the best it can and still be quite, pass epa standards and fit in the space aloud. It is designed for how it is sold. If you start adding and modding. Things change.

For maximum HP all the changes add up. Some do not work alone. But the fact is cooler intake charge adds power. More available air, the more you can add fuel. Just an air box mod, may not do anything but make it louder. But combined with a PC3 and Exhaust mods. Yes you will see a difference on a Dyno. I have seen it. It does work. But only if you use the extra air you’re giving the motor.

As for the Air filter, if you use the stock filter (and you can). You may want to remove the metal screen. That screen it self is very restrictive.
Just remember Yamaha has to jump through hoops (EPA) as well as make a bike that as many people as possible will like.
So it’s all a compromise.
Do what's right for you:)
 
NJFZ1 said:
Ok I will add my :2cents: to this discussion...

The way Ivan explained it to me was that the opening of the stock airbox was big enough to support the engine's level of HP power. However, because the way the air comes in to the airbox and has to turn you tend to lose velocity and therefore the amount of air that enters is somewhat limited by this. By opening the airbox you alleviate this condition a bit and it results in more power.

As those that have done the airbox mod can attest to there is a significant increase in intake noise. I think that Yamaha thought (correctly) that the majority of riders wouldn't want this additional noise and so the airbox was designed to support a certain level of HP while reducing noise. Everything that the OE manufactures do is a compromise of some sort, be it for noise, emissions or fuel economy.

For those of us that don't mind, and actually enjoy, the extra noise mod away :D
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Dam you beat me to it...lol:tup:
 
Im a little worried that the mod would affect the outcome of the M.O.T (Sha-ken) in Japan.

(They check for noise levels)

It might be wiser to buy a second air box and mod that. Use it till its time for the shaken then replace it with the stock.

I was also wondering about doing a partial mod like drilling holes to allow for more air but without changing the overall shape?

Also I read that a PCIII would be needed too.

Overall it sounds like more trouble than its worth!!
 
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I'm here to say, that my 2006 FZ1 runs excellent with the following mods.

1) Lars mod to the air box, and descreened stock filter.

2) Re-routed the wire harness to open up the holes/space in the frame for air flow.

3) Akrapovic slip on muffler, and removed the header cat.

4) Ivan's FCE.

5) My own design cut down flies mod. (Basicly, you remove them, and cut off the side that rotates up, and then put them back in. When you are done, 1/2 of the flies are gone, air flows better at low/mid range throttle, but you still keep some of the restriction, and that helps with the noise harmonics that reverberate up through the intake without them in there at all, or zip tied open.)

Leave the stock O2 sensor hooked up, and doing it's job.

Runs great.

With 16 tooth front, better control that throttle, or the front tire is lofted with ease... :)

I'm sure the Pipercross filter I have on order is really just a few hp more if anything, but hey, it's power... Besides, I'm pulling the tank up to put the Speedo DRD on, so it's time to upgrade the air filter... LOL

I really like the idea of having a stock airbox lid around if you have inspections to pass. Great news, they are less than 20.00 last time I looked. :)
 
I was apprehensive about cutting up the air box too. Before I started I called my local Yamaha dealer and priced a new air box bottom...$40 Canadian. For that price I thought, what the hell. I modified it. If I didn't like it I'd buy a new one. I LOVE it. I can't comment on the power increase because it wasn't dyno'ed. It "feels" more powerful in the midrange. But the intake growl is pure evil music!!! :wilynily:
 
I look at it this way... I've seen a lot of I-4 bikes that are not EFI where the rider has ditched it all and went with four individual aftermarket air filters. It they can let that much air in, so can I dammit! :D

Besides, just as a few have stated, I LIKE the sound! Let my "Girl" breathe!!!
 
Mods and Dyno

Has anyone out there done a full analysis of each mod (airbox, cat gut, slip on)? I mean, air box then dyno, then slip on then dyno, then cat gut then dynothen PCIII and dyno. If this were done, along with an exhaust analysis, a clear picture would be present of all mods and what is still in the realm of being legal with the best possible performance. Just curious. I personally do not have access to a dyno and this would be great info to have. I know from modding small block V8s and from what was stated early, for an engine to breath correctly, if you increase airflow in, use that extra air for more power, you must increase airflow out proportionally or a bottleneck is created.
 
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