Lets talk tuning

[madjack]

In responce to a reply questioning what V.E. calculations have to do with JB's an ecu's. First let me say, I do not consider myself a expert in any way. I have been intrested, an active in the tuning of v-twin engines for many years, an still seek the knowledge of some of the best in the industry, weekly.

With Volumetric Efficiency (V.E.) being used as a measure of a engines ability to fill the cylinders with air/fuel mixture. it's usually adressed as one of several tables that are adjusted in a process on a dyno to achive the best possible. The Procdure starts with the flow bench or known cfm numbers. If one was intrested in the knowledge I would try a find someone with The V-twin tuners handbook, by D. William Denish, Published by Crystal publications, Mesa Arizona. This book was what help me from the intrest to the beginning of understanding, whats involved in the tuning of the beloved v-twin

Now lets talk about the effects of changing the length of the inlet runners on the Rotax 990. Not having the heads pulled off of one at this point, my measurement is just a close estimate. but it's close to 11.5 in, from the top of the velocity stack to the inside edge of the exhust valve. By taking 2 in. out, you have dramaticlly changed the wave pulse that was designed into enginnering, thats comprized in the overall flow of this high rev air pump.

I've seen 6-10 hp lost by the removeal of a 1 in. spacer from a 120 ci 130hp/145tq v-twin, this is why I question the removeing of the velocity stack in the replacment of the (p.i.t.a.) air box before its been, properly tested on flow bench an dyno, thanks Gene

 

[boborgera]

In responce to a reply questioning what V.E. calculations have to do with JB's an ecu's. First let me say, I do not consider myself a expert in any way. I have been intrested, an active in the tuning of v-twin engines for many years, an still seek the knowledge of some of the best in the industry, weekly.

With Volumetric Efficiency (V.E.) being used as a measure of a engines ability to fill the cylinders with air/fuel mixture. it's usually adressed as one of several tables that are adjusted in a process on a dyno to achive the best possible. The Procdure starts with the flow bench or known cfm numbers. If one was intrested in the knowledge I would try a find someone with The V-twin tuners handbook, by D. William Denish, Published by Crystal publications, Mesa Arizona. This book was what help me from the intrest to the beginning of understanding, whats involved in the tuning of the beloved v-twin

Now lets talk about the effects of changing the length of the inlet runners on the Rotax 990. Not having the heads pulled off of one at this point, my measurement is just a close estimate. but it's close to 11.5 in, from the top of the velocity stack to the inside edge of the exhust valve. By taking 2 in. out, you have dramaticlly changed the wave pulse that was designed into enginnering, thats comprized in the overall flow of this high rev air pump.

I've seen 6-10 hp lost by the removeal of a 1 in. spacer from a 120 ci 130hp/145tq v-twin, this is why I question the removeing of the velocity stack in the replacment of the (p.i.t.a.) air box before its been, properly tested on flow bench an dyno, thanks Gene

:agree::agree::agree:

 

[Sarge707]

:agree::agree::agree:

:agree: Seat on the pants will Always feel better when you have spent Big Bucks$$$$. BRP Engineers know what their doing!!:shemademe_smilie:

 

[Firefly]

Interesting ideas.

Wouldn't the increased diameter at the top of the stacks also affect things?

In my situation, with the Evoluzione race air intake setup - I believe Ken (EV owner with tons of years in the auto and MC industry) ran it on a flow bench - not sure about the Dyno. He has sold the same units on Aprilla bikes for years - which essentially use the same engine.

I can ask him about this if you like....

I can tell you the throttle response was day and night better after installing this setup.

 

[madjack]

firefly, yes increasing or decreasing will change airflow velocity, my thinking would lean me to, incorperateing either the stock velocity stacks or evolution system to the Kewmetals. Atleast for a good starting place for testing.

I need to correct my previous thread, the measurement should be from the top fo the velocity stack ti the edge of the intake not the exhuast valve, sorry for that.

 

[BLACK WIDOW]

Theory

In response to a reply questioning what V.E. calculations have to do with JB's an ecu's. First let me say, I do not consider myself a expert in any way. I have been interested, an active in the tuning of v-twin engines for many years, an still seek the knowledge of some of the best in the industry, weekly.

With Volumetric Efficiency (V.E.) being used as a measure of a engines ability to fill the cylinders with air/fuel mixture. it's usually addressed as one of several tables that are adjusted in a process on a dyno to achieve the best possible. The Procedure starts with the flow bench or known cfm numbers. If one was interested in the knowledge I would try a find someone with The V-twin tuners handbook, by D. William Denish, Published by Crystal publications, Mesa Arizona. This book was what help me from the interest to the beginning of understanding, whats involved in the tuning of the beloved v-twin

Now lets talk about the effects of changing the length of the inlet runners on the Rotax 990. Not having the heads pulled off of one at this point, my measurement is just a close estimate. but it's close to 11.5 in, from the top of the velocity stack to the inside edge of the exhaust valve. By taking 2 in. out, you have dramatically changed the wave pulse that was designed into engineering, thats comprised in the overall flow of this high rev air pump.

I've seen 6-10 hp lost by the removal of a 1 in. spacer from a 120 CID HP/145tq v-twin, this is why I question the removing of the velocity stack in the replacement of the (p.i.t.a.) air box before its been, properly tested on flow bench an Dino, thanks Gene

I think that your theory is technically sound; However, it is my understanding that the design of the BRP air box was not a design necessarily for performance but compromised for noise abatement/reduction. This practice is not uncommon for production models sold to the general public, be it automobiles or motorcycles. The length of the intake stack to include the size and shape of the air box is to produce a quiet running machine (as much as possible) and to keep the intake noise down. A good example might be the air filter itself, it is not necessarily designed for performance but rather to be easily replaced and keep chunks of dirt out of the engine--Not for performance. There are many on this forum that would not buy the performance air systems just as there many that won't buy a performance exhaust simply because of the increased noise; regardless of the increased performance. Personally I can feel the increased power with my Hindle, JB, and KewlMetal air intake. What I cannot tell is what might be the optimum set up without extensive testing on a Dyno but its not hard to tell that the performance is certainly better than stock in more ways than one.nojoke

Michael:doorag:

 

[truck 85]

The biggest claim for velocity stacks is usually about straightening and smoothing (reducing turbulence) the incoming airflow at higher RPM's, helping to achieve maximum cylinder fill. Long stroke, large displacement V-Twins are especially susceptible to intake disturbance. I've wondered how critical they are on a smaller displacement, short stroke, multi valved engine, with much larger throttle bodies.:dontknow:

dont know about the throttle body size but on are 2006 Kawasaki we add about 3.5 inches to the velocity stacks.really helps adds about 5-10 hp. (but that is on alcohol never tryed it with gas)

 

[madjack]

Here's my theory at work. My ZX-14, at sea level, made 181 hp stock. With stock air box, d&d slip-ons, P.C. 190hp. With nothing other than playing around with 3 different length stacks, we ended up at 196hp.

My 02 ultra 103, forged heads D&D fatcat wild thing 26g cams,SERT tuner, 57mm tb,/1" spacer 123hp,127tq

My 02 kawa vulcan meanstreak, P.C., v&h big shots. air box converson, throttle body bored. 2.5 in velocity stack, 125hp, 101tq.

So theory or not, like I said, I'm no expert, just a guy that has spent some time an investment capital in this sport. What I don't do is buy somebodys doo-dad, bolt it on and tell the world how it's the best thing since goats milk. So I'll just crawl back into my little tuners world with all my theorys. See you all when, my wifes Syder can hold its own with my toys Thanks. Gene

 

[BLACK WIDOW]

doo-dads

Here's my theory at work. My ZX-14, at sea level, made 181 hp stock. With stock air box, d&d slip-ons, P.C. 190hp. With nothing other than playing around with 3 different length stacks, we ended up at 196hp.

My 02 ultra 103, forged heads D&D fatcat wild thing 26g cams,SERT tuner, 57mm tb,/1" spacer 123hp,127tq

My 02 kawa vulcan meanstreak, P.C., v&h big shots. air box converson, throttle body bored. 2.5 in velocity stack, 125hp, 101tq.

So theory or not, like I said, I'm no expert, just a guy that has spent some time an investment capital in this sport. What I don't do is buy somebodys doo-dad, bolt it on and tell the world how it's the best thing since goats milk. So I'll just crawl back into my little tuners world with all my theorys. See you all when, my wifes Syder can hold its own with my toys Thanks. Gene

It is obvious that you have good real-world experience and I for one certainly respect that. However, we don,t all have the luxury of having unlimited access to Dynos and the like for unlimited experimentation, so we buy "doo-dads" from people that do have and then evaluate their effect on the street.(against other stock spyders) If you would design a inlet stack that was a bolt on with the KewlMetal system and test it for performance I might buy that doo-dad also.nojoke
Keep us posted, my friend.

Michael:doorag:

 

[Magic Man]

Here's MHO after the last 40 years in bikes and racing

If you shorten the intake on these motors you most likely will see a drop in peak HP no doubt about it.

Now K&N makes some great air filters, and back in the 80s it was very common for guy the rip off the PINA air box from the then hot Suzuki and Yamaha fours and slap on 4 pod sytle K&N filters. Which at the time was common to do as in therory the K&Ns do flow more than the stock filter in the air box could.

It was indeed great to ease getting at and removing the carbs to re-jet 100%. However, when sombody finally put these same bikes on the Dyno, it was found they would not make as much HP as bike with a stock air box that just had the filter removed!

It was found that the rubber velocity stack that was made as part of the connector tube between the air box and rear of carb was the missing link.

This stack when removed in the installation of the K&Ns killed the performance more than the increase flow the filter could provide. It was shortly after that the filter companies started making many more high flow filters that still went into the stock air box rather than the ripping off the box and slapping on 4 pods.

These air box removals usually make the owner "think" his bike runs better" because the intake drone sounds "meaner" and he thinks it somehow runs better. It's kind of like the "King has new clothes" here a bit.

Most factorty air boxes do indeed consider noise reduction in there design 100%. However, just because it helps reduce intake drone dones not mean it automatically reducse it's ability to flow air. Most times the actual paper filter is the restriction not the box itself.

When we worked with GREEN Filter to design the ESI High Flow replacement filter for the Spyders their flow bench testing of the box showed it was more than up to the task of flowing enough air for this motor at 9000 RPMs and it was indeed the paper filter as the "weak link" so to say in the design.

Bottom line from a guy who makes his living designing things that the factory did not think of......

Just because the factory makes it does not automatically mean it is a bad thing.

These other air box replacements do indeed ease getting at things in the engine bay 100%.

But, on a fuel injected, modern day bike you don't have to re-jet adjust timing on, or really even "work on the power plant" that often. I'm not sure this extra ease at getting at things is worth the ripping off of the velocity stacks in doing so, nor the extra noise you have to live with if you do.

I think the "Spyder can't be easily run on a Dyno" excuse is making it a case of "buyer beware 100% " whenever you have to just take anybody's word on how a high performance option will work without cold hard numbers to back it up. Sometimes it's a bit of the "Sham WOW" selling without numbers to back it up.

Remember, just because it is louder, looks cool and sounds "meaner," does not mean it works better, or even as well as stock. :thumbup:

MM

 

[SpyderWolf]

I have been following these threads from a non-motorhead perspective. If you replace the air box, does that make it necessary to get the Juice Box? Is there anyway that the JB is making a bigger difference with the air box ripped out than it would on a stock system?

I have the Hindle exhaust on mine, but no other performance mods and am wondering what would give me the most bang for the buck?

 

[Sarge707]

Here's MHO after the last 40 years in bikes and racing

If you shorten the intake on these motors you most likely will see a drop in peak HP no doubt about it.

Now K&N makes some great air filters, and back in the 80s it was very common for guy the rip off the PINA air box from the then hot Suzuki and Yamaha fours and slap on 4 pod sytle K&N filters. Which at the time was common to do as in therory the K&Ns do flow more than the stock filter in the air box could.

It was indeed great to ease getting at and removing the carbs to re-jet 100%. However, when sombody finally put these same bikes on the Dyno, it was found they would not make as much HP as bike with a stock air box that just had the filter removed!

It was found that the rubber velocity stack that was made as part of the connector tube between the air box and rear of carb was the missing link.

This stack when removed in the installation of the K&Ns killed the performance more than the increase flow the filter could provide. It was shortly after that the filter companies started making many more high flow filters that still went into the stock air box rather than the ripping off the box and slapping on 4 pods.

These air box removals usually make the owner "think" his bike rins better" because the intake drone sounds "meaner" and he thinks it somehow runs better. It's kind of like the "King has new clothes" here a bit.

Most factorty air boxes do indeed consider noise reduction in there design 100%. However, just because it helps reduce intake drone dones not mean it automatically reducse it's ability to flow air. Most times the actual paper filter is the restriction not the box itself.

When we worked with GREEN Filter to design the ESI High Flow replacement filter for the Spyders their flow bench testing of the box showed it was more than up to the task of flowing enough air for this motor at 9000 RPMs and it was indeed the paper filter as the "weak link" so to say in the design.

Bottom line from a guy who make his living designing things that the factory did not think of......

Just because the factory makes it does not automatically mean it is a bad thing.

These other air box replacements do indeed ease getting at things in the engine bay 100%.

But, on a fuel injected, modern day bike you don't have to re-jet adjust timing on, or really even "work on the power plant" that often. I'm not sure this extra ease at getting at things is worth the ripping off of the velocity stacks in doing so.

I think the "Spyder can't be easily run on a Dyno" excuse is making it a case of "buyer beware 100% " whenever you have to just take anybody's word on how a high performance option will work without cold hard numbers to back it up. Sometimes it's a bit of the "Sham WOW" selling without numbers to back it up.

Remember, just because it is louder, looks cool and sounds "meaner," does not mean it works better, or even as well as stock. :thumbup:

MM

:agree: From a background of Many(20) Years of Jet Ski forums and Jet Ski Racing!!! :lecturef_smilie:

 

[Firefly]

Good sharing of information here.

Been awhile since I looked at my stock airbox-- but here are pics of the kewlmetal and evoluzione units showing their stacks. How much difference in height are we really talking about here?

 

[madjack]

As i was hpoing this topic, has produced some good dialoge an info.:chat:

Thanks firefly, for the pics. Can you guess which one I would pick, of the two? opcorn:

Black Widow, wondering, if there is room for a taller filter, between the bottem of the frame, an the top of the kewlmetals system. If thats so, I'm thinking ,by carefully cutting a old air box apart, we could put the stock velocity stacks on. Waa-laahyea:, Anybody have a old airbox, send it, I'll pay shipping, Gene

Pease don't take my replies in a harsh tone, I work better with tools than a keyboard. :thumbup:

 

[BLACK WIDOW]

Stack

As i was hpoing this topic, has produced some good dialoge an info.:chat:

Thanks firefly, for the pics. Can you guess which one I would pick, of the two? opcorn:

Black Widow, wondering, if there is room for a taller filter, between the bottem of the frame, an the top of the kewlmetals system. If thats so, I'm thinking ,by carefully cutting a old air box apart, we could put the stock velocity stacks on. Waa-laahyea:, Anybody have a old airbox, send it, I'll pay shipping, Gene

Pease don't take my replies in a harsh tone, I work better with tools than a keyboard. :thumbup:

The KewlMetal stack (measured from the inside openings to the bottom) is 1 1/2''. The stock stack measures 2''-- 1/2 inch difference.

Michael:doorag:

 

[BLACK WIDOW]

Replies

As i was hpoing this topic, has produced some good dialoge an info.:chat:

Thanks firefly, for the pics. Can you guess which one I would pick, of the two? opcorn:

Black Widow, wondering, if there is room for a taller filter, between the bottem of the frame, an the top of the kewlmetals system. If thats so, I'm thinking ,by carefully cutting a old air box apart, we could put the stock velocity stacks on. Waa-laahyea:, Anybody have a old airbox, send it, I'll pay shipping, Gene

Pease don't take my replies in a harsh tone, I work better with tools than a keyboard. :thumbup:

Certainly no offense taken on anything you have input to this forum, at least not from me. I totally enjoy good dialogue from experienced and learned folks.nojoke As far as room for a taller filter--Not much, maybe could squeeze an inch or so. But the stock stack is only 1/2'' longer than the KewlMetal stack so only 1/2 inch would be all the additional length requires inside the filter. I do think the stock stacks would fit under the filter (with a little trimmimg of the flare). The diameter of the filter is approximately 7''.

Michael:doorag:

 

[Campverdefela]

Why doesn't someone put at least these intake options to the Dyno test and see what is what? Seems like a lot of theory and guessing.

 

[BLACK WIDOW]

Dyno

Why doesn't someone put at least these intake options to the Dyno test and see what is what? Seems like a lot of theory and guessing.

Agreed, that would be the optimum solution, but is easier said than done with the Spyder.


Michael:doorag:

 

[Firefly]

As i was hpoing this topic, has produced some good dialoge an info.:chat:

Thanks firefly, for the pics. Can you guess which one I would pick, of the two? opcorn:

Black Widow, wondering, if there is room for a taller filter, between the bottem of the frame, an the top of the kewlmetals system. If thats so, I'm thinking ,by carefully cutting a old air box apart, we could put the stock velocity stacks on. Waa-laahyea:, Anybody have a old airbox, send it, I'll pay shipping, Gene

Pease don't take my replies in a harsh tone, I work better with tools than a keyboard. :thumbup:

I would guess you would lean towards the Evoluzione unit.

Sorry -- holding onto my stock airbox--- in the corner with my stock exhaust, headlights, etc.

No harshness going on at all--- been some good discussion on it all.

 

[madjack]

the stock air box

went under the knife today. Or should say the heat gun. With heat I removed the velocity stacks an the lid to vent inlet. The inlet is intresting to say the least.very restrive, in the amount of air it allows to pass. It has 2 separrate chambers, 2 small square orfices, for air to pass between.

I will be using the stacks, along with a evolutions race intake, an stock air box, In some testing. Won't be rite away, still have to adapt the dyno to accept the :spyder2:. Hopefully by spring there should be some data, to add to " my therories".lol:yes: Gene