My Version of the Airbox Mod to my '08

[Boneman]

What's an Air Box?

Sorry, had too. It's Friday and I'm bored....a dangerous combination! :rockon:

 

[jtarkany]

4 posts in this thread claim better performance, including yours:




And your own claim:


It might be semantics, but in my world better throttle response = performance gain. I know that if any of you felt that throttle response was worse you would consider it a negative impact on performance so the opposite must also apply.

I guess perception is reality...

You're right I should define. When I said throttle response was better that is a small performance improvement.

When I used to throttle up quickly my FZ would bog down for a second and then rev up, that is now gone.

 

[SovietRobot]

You're right I should define. When I said throttle response was better that is a small performance improvement.

When I used to throttle up quickly my FZ would bog down for a second and then rev up, that is now gone.

That's the first thing I noticed too.

It's a small, but noticable improvement, and it didn't cost anything.

 

[Wavex]

OK so here are the correspondences I've been having with the different Yamaha dealerships so far (start to read at the bottom of each post and make your way up):

===========================================
[email protected]
todavid******@gmail.com

dateFri, Apr 17, 2009 at 2:01 PM
subjectRe: FZ6 technical question


David,
The answer to that is yes and no. It depends on your motor and tolerance with that kind of mod. Tolerances very up to 3mm in a exhaust or intake port. This means you will have to try it. You may have to add a Power Commander for further adjustment. You will need to take a plug reading and look for popping at decell.

Johnny- Hide quoted text -

In a message dated 4/17/2009 9:50:57 A.M. Pacific Daylight Time, david*****@gmail.com writes:

Thanks Johnny for the response! However, I was trying to get a more accurate response about whether or not the FZ6 ECU and temp/pressure sensors would be able to adapt to a drastic increase in airflow from the Airbox... I have called Yamaha Motor's customer service line but they mentioned I'd have to call a Yamaha dealership, and if the dealership cannot answer, then I understand that you have a direct "tech line" you can contact. Could you please be so kind to forward them the questions to get confirmation?

Thank you again,

Regards,

David


On Wed, Apr 15, 2009 at 9:03 AM, <[email protected]> wrote:

David,
You are on the right track. This can cause a lean condition for sure. All the motors can have tolerances difference. In some cases this would make it perform better. In other cases the fuel injection could run lean. You friend may want to take a plug reading to see how it is burning. Another indication of a lean condition is popping at deceleration. Hope this helps answer you question.
Best Regards,
Johnny

Pacific Motorsports
1358 Pacific Coast Hwy.
Harbor City, CA. 90710
310-891-6990
310-891-6997 fax
www.pacificyamaha.com



To whom it may concern,

I own a 2007 Yamaha FZ6 and I have 2 friends with the same bike. One of them decided to modify his air box and effectively cut a big hole on the air box cover (before the air filter). The bike sounds a bit "throatier", and my friend claims that it increased the performance of his bike, but my other friend and myself are unsure about whether or not the FZ6's fuel injection system can compensate for this increased airflow to the engine to avoid a "lean" condition. The FZ6 does have a temperature sensor in the airbox, along with a pressure sensor in the intake manifold, but are these sensors enough for the ECU to automatically adjust its FI map? I read online that the FZ6 has a fixed FI map, so how would these sensors make the necessary adjustments if the map is fixed?

This has been posted on an online forum and we received a LOT of different opinions, but I am hoping a real Yamaha tech can help us establish the facts!
Your help is greatly appreciated!

David *******
18** ******* AVE
Long Beach, CA 90815
Cell: 714-***-****
david*****@gmail.com
===========================================

 

[Wavex]

Another correspondence with another dealership:

==============================================
fromDavid *******<david******@gmail.com>
toChristophe Convert <[email protected]>

dateTue, Apr 21, 2009 at 10:24 AM
subjectRe: FZ6 technical question
hide details 10:24 AM (0 minutes ago) Reply

Thanks Christophe,

Well opening the airbox cover allows for much more air to get to the engine... people are saying that it made their throttle response better and the engine "breathes" better as it is getting more air. The stock airbox cover is quite restrictive, so we are assuming that removing that restriction will in turn increase the amount of air available to the engine. If that's the case, there would be a risk to trigger a lean condition if the FI does not adapt.

I've emailed a couple of other Yamaha dealerships, and got 3 different responses... one of them states it will definitely make the engine run lean and we need to use a PCIII... the other ones says it's a matter of testing it because there are too many "engine tolerances" that come into play, so he recommends to check the plugs often and listen for deceleration popping... and finally your answer which basically states the opposite.

Again, we've been having these discussions for quite some time on our forum with everybody giving their own opinions on the matter, but we are still struggling to get the facts... I am not questioning your responses, but would it be possible for you use your "yamaha tech line" and have one of their technician send us a confirmation?

Thanks again for your time and help, we really appreciate it.

Regards,

David ******

fromChristophe Convert <[email protected]>
toDavid ******* <david******@gmail.com>

dateFri, Apr 17, 2009 at 3:29 PM
subjectRE: FZ6 technical question

hide details Apr 17 (4 days ago) Reply


As far as I can tell, the air box sensor should always read atmospheric pressure ahead of the filter. Why a sensor there? Because some days are 110degrees and others are 65. This will change the intake air density and therefore fuel must be adjusted to compensate. A filter by nature is restrictive and since it is the last hurdle for the airflow until the manifold, what else is there that could affect air speed?
Bottom line is normally aspirated engines operate in vacuums. Turbo charged engines manage to get 1 to 1.2 atmospheres of manifold pressure and they spin at over 100,000rpm!!!. What do you think you will get from cutting a hole in an air box aside from noise?

Sincerely.

JCC

From: David ****** [mailto:david******@gmail.com]
Sent: Friday, April 17, 2009 11:21 AM
To: Christophe Convert
- Hide quoted text -

Subject: Re: FZ6 technical question
- Hide quoted text -

Thanks Christophe, we agree on the "backyard mechanics"...

However, what makes you think that modifying the airbox ahead of the filter will not effect the volume of air being sucked in? If you are right, then it means there would be NO performance difference between before and after right? In other words I could have the bike dyno_ed before and after the mod and I wouldn't see any difference right?

I understand that most FI systems use a MAF sensor (Mass Air Flow) to determine the volume (or mass) of air that comes into the cylinders so that the FI can adjust accordingly... the FZ6 has a pressure sensor, or MAP sensor (Manifold Absolute Pressure) sensor which I understand is used to infer the mass air flow coming into the engine and make adjustments to the FI accordingly... so why have this sensor if the engine will "suck in" the exact volume of air it needs independently of the design of the airbox? What if I add a ram air to my airbox and increased the pressure inside the airbox (which is kinda what my friend is doing by cutting his airbox cover open and elliminating all restrictions the stock cover offers)? More pressure means more more air density, and in turn means there will be more air coming into the engine for each "suck in" cycle, right?

This is quite an interesting discussion and we've been going back and forth on the internet about this topic... lots of ppl have opinions, but I am confident we will find the facts somewhere!

I appreciate your help!

Regards,

David

On Fri, Apr 17, 2009 at 10:42 AM, Christophe Convert <[email protected]> wrote:
Dear David,

Anything you modify ahead of the air filter will have no effect on the volume of air been sucked in.
You will change the intake noise and that’s about it in my opinion.

Keep in mind that Yamaha spent millions of dollars to make your bike as perfect as possible under most driving circumstances. Playing around with an exacto knife to gain the extra ½ horsepower is a dangerous game that can end in costing you a fortune. We see backyard engineers coming to the shop regularly and trying to get their manufacturer’s warranty to foot the bill for their experiment. “it was like that when you sold it to me…”Huhh!
Any true technician will tell you: IF IT IS NOT BROKEN, DON’T FIX IT. And if you pretend to outsmart Yamaha’s engineer with an exacto knife, you are on your own…

Sincerely.

Hahm Motorsports

From: David ******* [mailto:david******@gmail.com]
Sent: Friday, April 17, 2009 9:54 AM
To: [email protected]
Subject: Re: FZ6 technical question

Kind Reminder.

Can anyone help? I bought my FZ6 from you guys!!

Also, I just called the Yamaha Motors customer service line and they mentioned I have to call you... and that if you can't help me, you have a direct "tech line" you can contact to get help...

Thanks,

David
On Wed, Apr 15, 2009 at 8:51 AM, David ****** <david*******@gmail.com> wrote:
To whom it may concern,

I own a 2007 Yamaha FZ6 and I have 2 friends with the same bike. One of them decided to modify his air box and effectively cut a big hole on the air box cover (before the air filter). The bike sounds a bit "throatier", and my friend claims that it increased the performance of his bike, but my other friend and myself are unsure about whether or not the FZ6's fuel injection system can compensate for this increased airflow to the engine to avoid a "lean" condition. The FZ6 does have a temperature sensor in the airbox, along with a pressure sensor in the intake manifold, but are these sensors enough for the ECU to automatically adjust its FI map? I read online that the FZ6 has a fixed FI map, so how would these sensors make the necessary adjustments if the map is fixed?

This has been posted on an online forum and we received a LOT of different opinions, but I am hoping a real Yamaha tech can help us establish the facts!

Your help is greatly appreciated!

David ******
18** ******* AVE
Long Beach, CA 90815
Cell: 714-***-****
david*******@gmail.com

 

[Wavex]

Another one:

===========================================
On Tue, Apr 21, 2009 at 8:46 AM, [email protected] <[email protected]> wrote:

David,

Your sensors are there to do minor adjustments and yes the FI map is fixed on the ecu, meaning it stays somewhat constant all the time, but to sum things up, you would definitely create a “lean” effect by letting more air in (cutting holes in the box) at greater amounts, as compared to your stock air box. The sensors only alter for elevation changes and air density. The correct way of doing a mod like this would most likely be to purchase a power commander, then you can adjust air/fuel ratios to make up for more air being sucked in.




From: David ****** [mailto:david******@gmail.com]
Sent: Friday, April 17, 2009 9:55 AM
To: [email protected]
Subject: Re: FZ6 technical question

Kind reminder. Can anyone help me?

I understand from Yamaha customer service line that you have a direct "tech line" you can contact for such questions so please help!

Thank you,

David
On Wed, Apr 15, 2009 at 8:49 AM, David ****** <david*******@gmail.com> wrote:
To whom it may concern,

I own a 2007 Yamaha FZ6 and I have 2 friends with the same bike. One of them decided to modify his air box and effectively cut a big hole on the air box cover (before the air filter). The bike sounds a bit "throatier", and my friend claims that it increased the performance of his bike, but my other friend and myself are unsure about whether or not the FZ6's fuel injection system can compensate for this increased airflow to the engine to avoid a "lean" condition. The FZ6 does have a temperature sensor in the airbox, along with a pressure sensor in the intake manifold, but are these sensors enough for the ECU to automatically adjust its FI map? I read online that the FZ6 has a fixed FI map, so how would these sensors make the necessary adjustments if the map is fixed?

This has been posted on an online forum and we received a LOT of different opinions, but I am hoping a real Yamaha tech can help us establish the facts!

Your help is greatly appreciated!

David ******
18** ********* AVE
Long Beach, CA 90815
Cell: 714-***-****
david*******@gmail.com

 

[Wavex]

As you can see, even Yamaha dealerships can't agree on this topic!

I am still waiting for responses from a couple of them... I am looking forward to reading one of them in particular, since he assured me he knows "a really good yahama tech, but he is on vacation until next week"... we shall see.

 

[jtarkany]

As you can see, even Yamaha dealerships can't agree on this topic!

I am still waiting for responses from a couple of them... I am looking forward to reading one of them in particular, since he assured me he knows "a really good yahama tech, but he is on vacation until next week"... we shall see.

Thanks for doing all of the legwork on this question. I really appreciate it, as I'm sure alot of others do as well.

 

[SANGER_A2]

As you can see, even Yamaha dealerships can't agree on this topic!

I am still waiting for responses from a couple of them... I am looking forward to reading one of them in particular, since he assured me he knows "a really good yahama tech, but he is on vacation until next week"... we shall see.

Thanks for this. I bet they're never all gonna agree though! This is one of those topics everyone has an opinion on and all backed up by different experiences/info/knowledge/guesses/rumours etc!

 

[urbanj]

i'm in the middle of getting a wideband setup with an egt probe as well. i'm going to use it for everything and anything but i will use it to datalog the differences between these mods and others. probably wont be for a month at least though since i have one usable arm from surgery

 

[Wavex]

i'm in the middle of getting a wideband setup with an egt probe as well. i'm going to use it for everything and anything but i will use it to datalog the differences between these mods and others. probably wont be for a month at least though since i have one usable arm from surgery

Sweet! That should settle the case!



Another email from Long Beach Motorsports this time:

=============================================
from M Sidner <[email protected]>
to david******@gmail.com

date Tue, Apr 21, 2009 at 4:22 PM
subject FZ6 tech question

hide details 4:22 PM (13 minutes ago) Reply



Hello David,
Thank you for inquiring to us about this issue. I would not advise that you modify your airbox. What I would advise you to do is get a Power Comander and that will increase performance. Also get a K&N air filter which will allow for more airflow as well as better performance. If you have any other questions please don"t hesitate to ask.

Sincerely,
Michael Sidner
[email protected]
=============================================

 

[Hellgate]

Can I jump in the fray too????

I've been reading a great book on four stroke performance tuning. There are many things that influence the performance of a given engine but the bottomline is that they must work in concert in order to get good overall performance.

The heart of any motor is the internal combustion area of the motor; piston dome shape, head shape and squish area. The key to performance within that is the squish area, that will determine how the air and fuel is combusted. If you've got a crap squish area you will be limited on the total potential of the motor. If you've got a good one you can really add good performance gains over the stock configuration if other factors are tuned correctly. Removing restriction from both the intake and the exhaust will help if it is done right. Rules of physics govern what will help and what will harm, period.

Over the past 10 years or so the tuning of motors has become much more precise instead of rumor and a "black art". For example, for years and years tuners used flow benches to "port and polish" the heads of a motor. Then the bike was taken to the track and the rider said, "Yeah I guess its better, it must be because we spend $1,200 on head work." Typically the tuner ported the head to flow the maximum air volume on the flow bench. This is great if all you wanted was the head to flow more air in a bench. The fact of the matter is many of the "experts" back then guessed based on rumor and wives tales.

What they were forgetting was Bernoulli's principle. In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. In other words, if you take porting past the size of the value you lose velocity of the fuel and air and the mixture is not thrusted into the cylinder at the correct speed and you loose power and $1,200. This holds true for the exhaust system and the intake system.

The other factor that is often not considered is the shape and the laminar flow in the given path (intake/exhaust). This must also be coupled with cam profile and lift. If not nothing is in sync and you spend a lot time and money of for not.

So what the heck does this have to do with the air box mod?

The snorkel of the air box is intentionally shaped to create a smooth laminar flow of the air. As the air passes through the opening the velocity of the air is increased and pressure is decreased. Once the air enters the airbox the opposite happens, the velocity deceases and the pressure increases (in relative terms) as the air fills the airbox. This provides a nice even spread to the air to each intake runner and have and even charge of air resulting a nice running motor, which the FZ6 is. If you remove the snorkel you will get more sound but you will disrupt the very beginning of the shaping of the air within the airbox and in will most likely have negative impact on overall motor performance. Why? The correct flow of air and fuel is not being delivered to the cylinder and the squish area can't squish is correctly.

Whew....

So don't mistake increased sound with performance and make sure changes are in concert with the whole package.

 

[maverick1970]

Wow that was a mouth full hahaha.... thanks for the explaination.

 

[urbanj]

What was the book called? i love reading new material.

 

[Hellgate]

What was the book called? i love reading new material.

Four-Stroke Performance Tuning by: A. Graham Bell, published by Haynes. It's written at university level and very, very detailed with specific tuning examples with dyno results of various changes. Fred lent it to me.

 

[Wavex]

Can I jump in the fray too????

Please do... and next time, please do it earlier you'll save me some work :thumbup:

Thank you for the great post.

 

[Fred]

Four-Stroke Performance Tuning by: A. Graham Bell, published by Haynes. It's written at university level and very, very detailed with specific tuning examples with dyno results of various changes. Fred lent it to me.

You're gonna love the sequels.

 

[Motogiro]

Is anyone saying that there's a performance increase WITHOUT fuel modification(PCIII/dynotune)?

The only experience I can attest to is I modified my air box, installed a K&N filter and got the bike bike dyno'd. I went from 87 RWHP. to 91 RWHP.

I already had 2Bros. exhaust & PClll installed.
Also I didn't have the stock Map running in the PClll because I was using the "Butt Dyno" and experimenting try to find a close MAP that would seem to work better with the 2 Bros. exhaust. (Not accurate at all)

So we're at basically at the same place as far as actual proof scientifically that this air box mod improves performance. We still need some one to dyno stock, make the airbox mod and dyno again.

I have to agree that unless you actually measure these performance ratios scientifically it's hard to actually say what the performance gains or losses are.

I'm also not saying the "Butt Dyno" can't tell performance gains, but I like the more scientific approach. It works in a more dynamic arena including accurate
air to fuel ratios which are also critical to the longivity of the motor.

Unfortunately it's not cheap to do. Fortunately it does make a big difference if done correctly.

 

[hiway]

From my quick read of the thread and my understanding of various aerodynamics and engineering background I think there are many "truths" being presented by about everyone.

The only way to really dispel this is to test how much air is introduced before/after mod. The dealership saying that it doesn't matter due to the air filter is part correct and part in correct. Due to various aerodynamics of the intake that the filter can draw upon etc. The filter does provide a buffer of sorts to limit the overall amount of air being introduced, but the opening that allows it to get air can affect this.

Venturi effect can create pressure from the aerodynamics of the intake which in theory could force more air also.

Quite a few variables involved...

A simple straight up dyno/map analysis would show what really is happening.

 

[SANGER_A2]

The only experience I can attest to is I modified my air box, installed a K&N filter and got the bike bike dyno'd. I went from 87 RWHP. to 91 RWHP.

I'll tell you a great experience after doing this mod. Get up to 6th gear and then slow down to 10-15mph. Then lay on the gas. You can hear the bike sucking in the air hard and it sounds great! :rockon: