[Flyerdon]

I've been an avid rider of motorcycles since 1965 and I've also seen a lot of trends since that time. One that was around then and still is to some extent, is to scrap the stock air intake system and replace it with the most minimum contraption available, including open bell mouths in some cases. Why, is the big question. A lot of people simply want easy access to whatever is over, under, or simply beyond the air box or think minimizing the stuff on the bike makes it look faster. I've done it myself quite a few times ( mostly back in the 80's when carbs were about the only fuel mixers in use). A few times it worked if I was able to re-jet and get it right but there were also some down right duds mixed in that had to go back to stock.

Kevin Cameron had several articles in Cycle World (you can still look some of them up) and he technically explained why modern air boxes are made to actually tune the intake system, not just to make a holder for the air cleaner(s). I haven't seen it mentioned on this forum very much but recently did see a post where someone ditched the stock setup for individual foam units. If you follow some of the info in this article, although some of the replies are from Snow mobile people, you'll get a good idea of just how hard it is to get it anywhere close to how good the stock setup is right from the factory.

Airbox design/theory by Kevin Cameron - Mach Z / Mach 1 / Formula III Triples

Page 1 of 2 - Airbox design/theory by Kevin Cameron - posted in Mach Z / Mach 1 / Formula III Triples: Some of you know (and might be tired of hearing it!) that when it comes to fast trail sled tuning Im a proponent of running the stock airbox. More than a dozen years ago I ran across this story...

www.dootalk.com

We have to face it, along with making the vehicle so it clears all the required, mandated EPA laws, mother Yamaha has all the expensive stuff it takes to build a system that makes the best power over the broadest possible range. It's simply all but impossible to do what the factory does with the individual's tools we all have in the garage, even the guys who have just about everything. Not many people (well actually no one) I know has a dyno so they can check the output on their bike after making any performance changes. Far too many riders make changes to their intake and/or exhaust systems because they look or sound "cool" but actually decrease power output and some times by a lot. So if you are looking at changes for performance gains, make sure you are getting gains nd not reductions, no matter how cool you think you made your ride.

 

[Slonomo]

Woof I feel called OUT😂😂😂 I'll be the first to admit I'm a bit of a dumb ass. I'm ok with that. You are absolutely correct in everything you just stated. Don't think for a second I think I know better than years of research and development. But damn. Again. Called OUT😂 just let me be an idiot in peace hahaha

 

[SleviN]

what is your opinion of those who have modified the airbox, mainly just removing the snorkel and found it to be less restrictive and allowed for more power?
I haven't messed with the airbox at all on mine but I've seen interesting results from others.

 

[Toxana]

I'm guessing that there are others like me that would trade off (some) raw performance and efficiency for looks or sound. As long it doesn't compromise "ridebility", i.e. big dips of power or jerky response etc. That is why I contemplated getting some TCK80 when I'm ridding 100% on tarmac. The other no go is reducing security (probably why I didn't get the TCK80 so far).

I love modifying and riding my modified bike. It's inexplicable how amazing it makes me feel riding something I dream of and turn it real. That feeling is worth many bhp to me.

I guess what I want to say is that people value different things and like different things. And that is ok.

I do really appreciate also that many of you more knowledgable and experienced riders and mechanics take the time to educate the rest on pros and cons of some changes. This is help us make better (conscious) decisions. Thank you.

 

[KLX678]

I'll confess that I am doing an exhaust system without any thought for performance. It is about looks and tone. I want better lower tone from the exhaust, not volume, but tone. I also want a better looking pipe for my preferences. If it does anything for performance I doubt I will really notice it.

I will also confess that I've blown roughly $700 on suspension components which I do want to affect performance since they won't be prominent by any stretch tucked in the forks and buried in the frame. I spent a whole lot more on the suspension.

 

[Flyerdon]

I try to bring up issues like the air box only because I've gained a lot of knowledge over the past 56 years tinkering on bikes. When we start out we know a very little and start the learning process by trying things we see and in many cases we follow trends or fantasies that simply don't deliver what we think they will. As someone who both won and lost at trying new things I just try to point out what seems to work and what doesn't. Each person can do the same but it is helpful to get some basic advice when it's available and have a good understanding of what a result is likely to be when working with a very complicated machine that was designed to function to the maximum extent and still meet the mandated requirements to make it legal for street use. There are places where the EPA regulations are upheld and violators fined and that may be somewhere outside your own area, especially when traveling. I try to keep that in mind because I cross local and state boundaries every year, even countries when I scoot up into Canada.

 

[Slonomo]

I try to bring up issues like the air box only because I've gained a lot of knowledge over the past 56 years tinkering on bikes. When we start out we know a very little and start the learning process by trying things we see and in many cases we follow trends or fantasies that simply don't deliver what we think they will. As someone who both won and lost at trying new things I just try to point out what seems to work and what doesn't. Each person can do the same but it is helpful to get some basic advice when it's available and have a good understanding of what a result is likely to be when working with a very complicated machine that was designed to function to the maximum extent and still meet the mandated requirements to make it legal for street use. There are places where the EPA regulations are upheld and violators fined and that may be somewhere outside your own area, especially when traveling. I try to keep that in mind because I cross local and state boundaries every year, even countries when I scoot up into Canada.

So for the sake of educating all us who know nothing about bikes and internal combustion engines, what is it that you've learned from modifying bikes for the last 56 years? How have you found modified airboxes to be detrimental to performance? What are the symptoms? And on what bikes have you found these results?

 

[Slonomo]

I should note. I'm not trying to be disrespectful or question your knowledge, merely begin discussions and further a collective knowlage base.

 

[Renzo750]

I'm prepping right now to do some dyno work.

My choice of pipe is a Leo Vince (I started with both db killers in) and have now left the muffler db killer in and took the one between the pipe and muffler out (It looked pretty restrictive). Like KLX678 I did this to dial in the sound and tone - it's throaty and has a nice tone without being overly loud and obnoxious.

Now I'm evaluating the airbox. My plan is to do the first pull with the stock air box for a base; then swap to the (expensive) DNA kit (opens up the top of the airbox); I do not plan to remove the internal snorkels as I expect that we will find that they are important for intake velocity.

Once the kit gets here I'll post some pics and measurements

The bottom line is this kind of work really needs to be done on a dyno and with programing and full mapping capabilities. I'm fortunate to be friends with one of the very best tuners in the county and we've worked together on other bikes with amazing results. Doug is always looking forward to a new project and we've talked about the plan. I'm not after absolute max power in the sense that I'm doing more engine mods - I just want to have as efficient of air pump as I can get and have everything that can be had via professional dyno tuning.

How to Tune and Modify Motorcycle Fuel Injection Systems : Doug Lofgren : 9780760330722 (bookdepository.com)

 

[Flyerdon]

So for the sake of educating all us who know nothing about bikes and internal combustion engines, what is it that you've learned from modifying bikes for the last 56 years? How have you found modified airboxes to be detrimental to performance? What are the symptoms? And on what bikes have you found these results?

The very worst situation I ran across was a 1978 Kawasaki KZ650 custom that ran like a champ when it was stock. Then I got the bright idea of putting K&N filter pods on it, and I believe I also put a Kerker header on it. The bike "looked" good but mid range was rough and full tilt was horrible. I rejetted and rejetted but never did get it to run anywhere as good as stock. I had a 2004 Harley Superglide that I put a Harley kit on with Hines sure shots and an aftermarket air cleaner (the Kit was actually a displacement increase up to 92 cubes I believe and a cam change. When it was dynoed, it actually made about 10 h.p.less and the torque was way lower. It's been my experience that carbed engines are much harder to get right but that doesn't mean the FI engines, especially motorcycle engines, don't come from the factory just about as good as they are going to get and I mean across the range from Idle to full on max. You don't have to take anyone's word but just do some reading and studying the guys who make a living trying to get engines to outperform the OEM units. A rule of thumb used to be about $100/h.p. but it's far more than that now, probably five times that.

 

[Slonomo]

The very worst situation I ran across was a 1978 Kawasaki KZ650 custom that ran like a champ when it was stock. Then I got the bright idea of putting K&N filter pods on it, and I believe I also put a Kerker header on it. The bike "looked" good but mid range was rough and full tilt was horrible. I rejetted and rejetted but never did get it to run anywhere as good as stock. I had a 2004 Harley Superglide that I put a Harley kit on with Hines sure shots and an aftermarket air cleaner (the Kit was actually a displacement increase up to 92 cubes I believe and a cam change. When it was dynoed, it actually made about 10 h.p.less and the torque was way lower. It's been my experience that carbed engines are much harder to get right but that doesn't mean the FI engines, especially motorcycle engines, don't come from the factory just about as good as they are going to get and I mean across the range from Idle to full on max. You don't have to take anyone's word but just do some reading and studying the guys who make a living trying to get engines to outperform the OEM units. A rule of thumb used to be about $100/h.p. but it's far more than that now, probably five times that.

It doesn't really matter what type of machine it is, any OEM vehicle or engine is tuned to max HP while still confirming to EPA regulations. Generally there is HP to gain if emissions equipment is tampered with. Where I'm from, that's not a big deal to anyone. Unless you're driving a big diesel truck that billows black smoke everytime you look at the throttle. The province just started handing out $1000 environment fines for the diesel bros. For those who have to deal with emissions testing, keeping your bike stock is about the only way to keep it insurable. I have a local motorcycle shop that has a dyno. I'm really curious about how different intake set ups will change the power band and overall power output. The plan is to put this all to rest with actual evidence. That may take a few months as it was -37°c here this morning and I ain't bringing the bike over to the shop till it's sweater weather. Internal combustion engines are just big air pumps. Rule of thumb is if you can flow more air, and supply enough fuel, it will at the very least run more efficiently.

From what I can gather, the xsr's airbox is designed to be a choke point. That helps it run lean, and it smoothes the power band out to feel very gradual. Which is why when people do exhausts and intakes on the bikes, they notice a good/bad difference in power. As soon as you get rid of the factory air box, the factory tune will no longer supply enough fuel to run efficiently. It is very important to get proper tuning done when messing with integral, specifically designed components. Not only tuning but hardware as well. Does anyone know the flow rate of the factory injectors? I can't find that info anywhere. With a free flowing exhaust and intake, do the stock injectors have enough flow rate to keep everything healthy? All stuff I'll figure out on the dyno, but makes me curious just the same.

 

[REXxsr700]

I've been an avid rider of motorcycles since 1965 and I've also seen a lot of trends since that time. One that was around then and still is to some extent, is to scrap the stock air intake system and replace it with the most minimum contraption available, including open bell mouths in some cases. Why, is the big question. A lot of people simply want easy access to whatever is over, under, or simply beyond the air box or think minimizing the stuff on the bike makes it look faster. I've done it myself quite a few times ( mostly back in the 80's when carbs were about the only fuel mixers in use). A few times it worked if I was able to re-jet and get it right but there were also some down right duds mixed in that had to go back to stock.

Kevin Cameron had several articles in Cycle World (you can still look some of them up) and he technically explained why modern air boxes are made to actually tune the intake system, not just to make a holder for the air cleaner(s). I haven't seen it mentioned on this forum very much but recently did see a post where someone ditched the stock setup for individual foam units. If you follow some of the info in this article, although some of the replies are from Snow mobile people, you'll get a good idea of just how hard it is to get it anywhere close to how good the stock setup is right from the factory.

Airbox design/theory by Kevin Cameron - Mach Z / Mach 1 / Formula III Triples

Page 1 of 2 - Airbox design/theory by Kevin Cameron - posted in Mach Z / Mach 1 / Formula III Triples: Some of you know (and might be tired of hearing it!) that when it comes to fast trail sled tuning Im a proponent of running the stock airbox. More than a dozen years ago I ran across this story...

www.dootalk.com

We have to face it, along with making the vehicle so it clears all the required, mandated EPA laws, mother Yamaha has all the expensive stuff it takes to build a system that makes the best power over the broadest possible range. It's simply all but impossible to do what the factory does with the individual's tools we all have in the garage, even the guys who have just about everything. Not many people (well actually no one) I know has a dyno so they can check the output on their bike after making any performance changes. Far too many riders make changes to their intake and/or exhaust systems because they look or sound "cool" but actually decrease power output and some times by a lot. So if you are looking at changes for performance gains, make sure you are getting gains nd not reductions, no matter how cool you think you made your ride.

I've been an avid rider of motorcycles since 1965 and I've also seen a lot of trends since that time. One that was around then and still is to some extent, is to scrap the stock air intake system and replace it with the most minimum contraption available, including open bell mouths in some cases. Why, is the big question. A lot of people simply want easy access to whatever is over, under, or simply beyond the air box or think minimizing the stuff on the bike makes it look faster. I've done it myself quite a few times ( mostly back in the 80's when carbs were about the only fuel mixers in use). A few times it worked if I was able to re-jet and get it right but there were also some down right duds mixed in that had to go back to stock.

Kevin Cameron had several articles in Cycle World (you can still look some of them up) and he technically explained why modern air boxes are made to actually tune the intake system, not just to make a holder for the air cleaner(s). I haven't seen it mentioned on this forum very much but recently did see a post where someone ditched the stock setup for individual foam units. If you follow some of the info in this article, although some of the replies are from Snow mobile people, you'll get a good idea of just how hard it is to get it anywhere close to how good the stock setup is right from the factory.

Airbox design/theory by Kevin Cameron - Mach Z / Mach 1 / Formula III Triples

Page 1 of 2 - Airbox design/theory by Kevin Cameron - posted in Mach Z / Mach 1 / Formula III Triples: Some of you know (and might be tired of hearing it!) that when it comes to fast trail sled tuning Im a proponent of running the stock airbox. More than a dozen years ago I ran across this story...

www.dootalk.com

We have to face it, along with making the vehicle so it clears all the required, mandated EPA laws, mother Yamaha has all the expensive stuff it takes to build a system that makes the best power over the broadest possible range. It's simply all but impossible to do what the factory does with the individual's tools we all have in the garage, even the guys who have just about everything. Not many people (well actually no one) I know has a dyno so they can check the output on their bike after making any performance changes. Far too many riders make changes to their intake and/or exhaust systems because they look or sound "cool" but actually decrease power output and some times by a lot. So if you are looking at changes for performance gains, make sure you are getting gains nd not reductions, no matter how cool you think you made your ride.

I haven’t replaced or modified the aspiration of any of my motorcycles since the use of computer controlled fuel injection. I cannot justify the cost of time and money for the small increase (or loss) of performance. Granted, some aftermarket systems took and sound great, but.

 

[Flyerdon]

It doesn't really matter what type of machine it is, any OEM vehicle or engine is tuned to max HP while still confirming to EPA regulations. Generally there is HP to gain if emissions equipment is tampered with. Where I'm from, that's not a big deal to anyone. Unless you're driving a big diesel truck that billows black smoke everytime you look at the throttle. The province just started handing out $1000 environment fines for the diesel bros. For those who have to deal with emissions testing, keeping your bike stock is about the only way to keep it insurable. I have a local motorcycle shop that has a dyno. I'm really curious about how different intake set ups will change the power band and overall power output. The plan is to put this all to rest with actual evidence. That may take a few months as it was -37°c here this morning and I ain't bringing the bike over to the shop till it's sweater weather. Internal combustion engines are just big air pumps. Rule of thumb is if you can flow more air, and supply enough fuel, it will at the very least run more efficiently.

From what I can gather, the xsr's airbox is designed to be a choke point. That helps it run lean, and it smoothes the power band out to feel very gradual. Which is why when people do exhausts and intakes on the bikes, they notice a good/bad difference in power. As soon as you get rid of the factory air box, the factory tune will no longer supply enough fuel to run efficiently. It is very important to get proper tuning done when messing with integral, specifically designed components. Not only tuning but hardware as well. Does anyone know the flow rate of the factory injectors? I can't find that info anywhere. With a free flowing exhaust and intake, do the stock injectors have enough flow rate to keep everything healthy? All stuff I'll figure out on the dyno, but makes me curious just the same.

The manual only has fuel line pressure going into the injector lines but I doubt the rate of flow at the injectors would be a problem because usually the way you get more fuel into the combustion chamber is by lengthening the duration the injector is open and that only takes a vey small amount of time. If a person is using a PC3, 5, or similar device the tables allow you to increase that duration up quite a bit.

 

[Domster]

Flyerdon I think you have articulated very well what I, deep down, thought all along about fiddling around with machinery that cost billions of yen to develop properly. I like the idea of a slightly different note for the exhaust, but the fugly thing we have been given is going to stay on mine. Instead I'll stick on some new Pirellis, dump the shock for a Hagon (changed the fork springs already) and then just ride the thing.

 

[hombacher]

I like the idea, that all those parts like airbox, cat, the exhaust with its muffler is only invented and built in your bike is done to treat you.
The more North America you come, the more it is a common sense and it is burned in the brains. The idea that there was a demand in regard to a sustainable solution to reduce the toxic exhaust gases to avoid acid rain and to keep us alive on that globe, that does not come in mind. No this is only restrictive and for sure only limits the possibilities of my actual ride.

The fact is, since 2014 little CP2 engine is available and can be purchased in different types of motorcycles. But I did not find one successful modification, in which a bunch of hidden cavalli or horsepowers were found, because of restrictions. I did not find one write up or dyno run in which electronic limiters were programmed in to create some artificial restriction such as gear limiters or comparable.
I only found things like ripping away the airbox, install a full open exhaust and then start to heal what was damaged. Either by piggy pack solution or reflash of ECU, it is reported of some 10% power gain at top of the powerband. 10% or for about 7 to 8 HP that does not even meet the conservative tuning calculation, as the changes listed before are about 1000 bucks.
And that is the real point of pain, the power gain is at the top end, yeah!



In these days motorcycle journalists got the chance to test ride new Euro 5 MT-07. It is the same story as already told with new Tracer 700, which was shown last year already. The nominally horsepower dropped from 75 HP to 73 HP, but nobody gets aware of it, when riding. Yamaha just created the top power peak some 250 rotations lower and everybody rides felt the same powerband as before, responsive on every twist of the wrist and continuously reving to top into the limiter at top.

That is one thing what I am missing, I need a flash light for my shifting points...

 

[Flyerdon]

From the very outset, if you look at the early advertising for the XSR line, personalizing the machine was something Yamaha had up their sleeve. There are some pretty nifty versions done by shops that customize as a business but like all things, the process of customizing is also personalizing and therefore it limits how the thing will be used so what is my "cup of tea" may not be yours. There are new bikes in the 700 class that make a little more power or have "better" suspension or fancier electronics but for the most part, the XSR and the MT version are pretty darned good bangs for the buck and for the number of bucks I have to spend on a bike, I'm pretty satisfied.

 

[Renzo750]

DNA Air Box Kit compared to OEM.
Plan to get on the dyno next week

 

[Flyerdon]

That should be interesting to actually see how the new setup compares to the stock setup. I'm running a K&N filter but left the rest of the intake as stock. After I put the K&N in, I also changed my exhaust to a Yoshimura R77 and I removed the external snorkle. I also had my ECU reflashed. Does it seem to have any more power? It's really hard to say but I've never had a dyno run so until I can find a place that will put it on their dyno, I'll just leave it there. The local H.D. dealer isn't very excited to run a competitor's bike on their dyno.

 

[Renzo750]

OK - so dyno work is complete. The base run was done with the Leo Vince pipe and one of the two db killers left in. (The can db killer is in, the pipe/can junction db killer out). Sounds perfect which is why this configuration was maintained. The fueling was decent with only the pipe but did have some minor fluctuations from ideal. The pipe alone would not have "required" remapping, but it could have been unproved upon.

The DNA filter was added and fueling was VERY lean between 4500 and 5500 - DNA states in no uncertain terms that a remapping is required - they are absolutely correct, running this filter without remapping will end badly.

Once the mapping was worked out the DNA filter added considerable low end and mid-range performance from the bottom all the way up to about 7500 rpms. At the top we technically lost a little power but the power drops off flatter. The reason seems to be the intake snorkel length/flow is the limiting factor within the air-box - I left them in as my goal was met by the improvement of low and mid-range power - that will be a very noticeable improvement in overall rideability.

The one thing that was interesting is that as the rpm's reach redline the bike "over-fuels" to soften the hit of the rev-limiter. The cylinders also do not use the symmetrical fuel maps; this accounts for the 270 degree crank - we maintained the factory relationships and linked the mapping to concur with the factory variances between cylinders.

Overall I'm very pleased with the results, while I was "expecting" some peak power increase, when one of the very best tuners in the country spends as much time adjusting individual data points to precisely manage idea fueling it's worth every penny to know that the engine working at it's very best fuel/air mixture throughout the entire rev range, even if I didn't realize an increase in peak power. The bike gained considerable HP and torque where it's most important (low to upper mid rpms) and will enhance smoothness & rideability tremendously.