Secondary Butterflies

[Bob Skinner]

Barely able to understand what you all are describing, but I see the issue somewhat differently. Forget the water hose, water isn't compressable but air is.
 my simple mind is seeing the effect the engine feels (with proper tuning of the software) similar to stacking and compressing the air above the secondary flys like to supercharger vs no supercharger.
This all runs into the voodoo around can design/intake manifold tuning/engine volum in automobiles.
My first exposure to this was the old nail head (small valves) Buicks which ran like hell.

[B.D.F.]

Well, I am not quite seeing the relationship. This whole issue is about putting a valve in a circuit that flows a fluid (air) due to low cylinder pressure. A supercharger is a pump that compresses air and quite literally forces more fluid (air) through an engine that it could pump given no restriction whatsoever. A valve can only restrict flow where a pump can only cause more fluid to flow.

But hey, should someone's house catch fire, and the firefighters come to put it out, ask them to close the valves on the truck 1/2 to increase the amount of water they are putting on the house.

 


"A little learning is a dangerous thing;
drink deep, or taste not the Pierian spring:
there shallow draughts intoxicate the brain,
and drinking largely sobers us again."
-Alexander Pope  1709

Brian

Barely able to understand what you all are describing, but I see the issue somewhat differently. Forget the water hose, water isn't compressable but air is.
 my simple mind is seeing the effect the engine feels (with proper tuning of the software) similar to stacking and compressing the air above the secondary flys like to supercharger vs no supercharger.
This all runs into the voodoo around can design/intake manifold tuning/engine volum in automobiles.
My first exposure to this was the old nail head (small valves) Buicks which ran like hell.

[Steve in Sunny Fla]

Relationships are now the question?

  Ok, let's see... how about the relationship between throttle body sizing to fill a 300cc cylinder at 100% efficiency at 9000 rpm, and what's needed to fill the same cylinder at 100% in 4500 rpm. Are they the exact same? could there be a relationship there?

 How about the relationship between not just one isolated cylinder, but 4 cylinders, all drawing from the same airbox. Could there he a relationship there?

 Could there be a relationship between the incoming charge being impeded by a reverse, back flowing charge, because there was enough TIME for that back flow to occur?

  Perhaps there may be relationships going on that aren't quite explained away by the hose / bucket theory.

  And since quotes apparently validate posts, this one comes to mind:

  "everyone has a plan until they get punched in the face"... George Foreman

 Steve

[Steve in Sunny Fla]

Forget the water hose, water isn't compressable but air is.

 my simple mind is seeing the effect the engine feels (with proper tuning of the software) similar to stacking and compressing the air

  This is getting at the meat of it. Steve

[Rembrant]

   
   IMO, since there obviously power to be made by removing flies or reflashing the ecm,  I think the obvious correct tuning procedure would be to have the flies controlled by the ECM, but with optimized opening to create the best cylinder filling at lower rpms. With this in mind, I feel this negates the argument that reflashes are only so someone can have "something to sell". Unless those proposing fly removal can support it's superiority over a proper secondary tune from the ECM, they are only GUESSING.

  Think about it.

 steve

Steve,

I realize you're only posting your opinion here, but there are a lot of people on these forums (like the "engineer types") that do a lot more than just "think about it" and "guess".

The performance differences between a flashed ECU and a PC5 with flies removed is an old discussion now. I had to check the date stamp on this thread as it initially looked like it was from 2011. I think the dyno charts have long proven the power gains of PC5/flies out over a flashed ECM. The fact that the bikes with PC5's and flies out make a significant amount more HP/TQ than a bike with a flashed ECU tell the story all on their own...with no guessing what so ever. Somebody would have to present some pretty impressive data to prove to me that a bike making 145HP has better "volumetric efficiency" than a bike making 160HP.

An off-the-shelf flashed ECU is considered to be a mild power upgrade. Always has been. They're convenient, low fuss, and easy to do for the end user. They're not "the correct" tuning option as you put it....they're just a different tuning option for those looking for a mild upgrade. No more, no less.

You know what a lot of people guess about? They guess about what is being done, or what has been done inside their ECU. People think that there is all kinds of "careful tuning of the secondary flies" going on, and thorough scientific work to create a very specialized map for the flies that optimizes performance. The truth is, the flies are just programmed to open as early as possible...there's really no "tuning" as people typically perceive.

I wish I could show people the inside of their ECU...stock or tuned, so that they could see just how simple it really is. No voodoo...nothing scientific, just graphs and numbers. A highschool kid with good math skills could create a "carefully tuned" secondary fly map in about an hour....likely less. I'm not saying that flashed ECU's are "just something to sell", but if you saw what was in them, you might be just a little bit disappointed in what you're getting for your money.

The people I feel bad for are the guys that had their ECU's flashed an then felt little or no difference at all in performance. To add insult to injury, when they inquire on these forums, they're usually told that there is obviously something seriously wrong with their C14, or they're just a village idiot and they don't "feel" the gains. Meanwhile, the next guy with a freshly flashed ECU comes along and he's doing power wheelies and breaking the back tire loose all the time. Now that's something to think about IMO.

Rem

[maxtog]

The people I feel bad for are the guys that had their ECU's flashed an then felt little or no difference at all in performance. To add insult to injury, when they inquire on these forums, they're usually told that there is obviously something seriously wrong with their C14, or they're just a village idiot and they don't "feel" the gains.

I don't feel bad for those VERY few, I just wonder what is wrong with the way they ride that they can't tell the obvious difference.

Meanwhile, the next guy with a freshly flashed ECU comes along and he's doing power wheelies and breaking the back tire loose all the time.

And although the difference is obvious and nice, it is not that different.

[gPink]

I like motorcycles. I like to talk to people who like motorcycles. I like to listen to and learn things from people who I believe know more about motorcycles than I do. People who know more than me consists of a very big group of people. I like hearing opposing ideas, theories and opinions. It contributes to my knowledge base.

What I don't like is when egos get in the way. It is detrimental to the discussion and diminishes all involved. I find it takes the fun out of the very reason I like these discussions.

So to all...carry on in the way you believe best.

Gary

[Rembrant]

I don't feel bad for those VERY few, I just wonder what is wrong with the way they ride that they can't tell the obvious difference.

If they ride the bike over 4000 RPM often, and use their gearbox to stay in the power range, they likely won't feel any difference. It's simple. The flies opening early gives a boost in power in the 1500-3500 RPM range, which is fine for the guys that usually cruise in the lower rev range. It is often said that high RPM or peak power increases are useless on a sport-touring bike....and that nobody will use that power. I couldn't disagree more. When I'm riding along the highway at 3800 RPM with my wife on the back and the bike loaded with gear, I want my bike to pull hard above that 4000 RPM range when I pull out to pass. At this point and time, the fact that ECU flashed flies were opened early at 2500 RPM make zero difference.

And although the difference is obvious and nice, it is not that different.

That's a different song than you used to sing Max. You used to even use all caps when mentioning the HUGE and MASSIVE power gains you found with your flashed ECU. Now, the difference isn't that much? C'mon Max, at least be consistent...lol.

Rem

[pasini510]

"I don't feel bad for those VERY few, I just wonder what is wrong with the way they ride that they can't tell the obvious difference."

Thought the same thing Max

[Rembrant]

What I don't like is when egos get in the way. It is detrimental to the discussion and diminishes all involved. I find it takes the fun out of the very reason I like these discussions.

So to all...carry on in the way you believe best.

Point taken Gary, you're right.

Rem

[maxtog]

If they ride the bike over 4000 RPM often, and use their gearbox to stay in the power range, they likely won't feel any difference. It's simple. The flies opening early gives a boost in power in the 1500-3500 RPM range, which is fine for the guys that usually cruise in the lower rev range.

I do notice it most there, but I also notice it all the way through about 4500...  although it is diminishing.  And like I said before in the other thread, if you throw it in a low gear and instantly wind up for aggressive driving, I don't think the flies stuff matters much.  But for normal and spirited driving (the words I have used several times now), it makes a huge difference.

That's a different song than you used to sing Max. You used to even use all caps when mentioning the HUGE and MASSIVE power gains you found with your flashed ECU. Now, the difference isn't that much? C'mon Max, at least be consistent...lol.

It *is* a huge difference, in the range that matters, like I explained.  It is not a wheelie making machine, and never implied it was.  It doesn't increase peak horsepower, it lifts a limp area.  I originally described it as removing the wet rag stuck in the intake during the lower to mid RPM.

[Steve in Sunny Fla]

 Rem, I get your point BUT you may have missed the subtleties of mine. I never suggested the reflash, as it is now known, is "properly tuned". My point is that I believe a careful adjustment to the fly map, taking gear selection into consideration, could offer advantages in power vs flies out at 5k and down.

 I would like you to clarify one thing for me though - everything I have read would indicate that flies in or out has zero effect at WOT, as the flies are WOT too. You point out a 15hp difference is achievable. do you know anyone who has used the same bike and the same dyno, and done back to back testing, flies vs no flies? I place no faith in different bikes / different dyno's as a tuning constant.

 A last point, you mention what's inside the ECM. IMO, it's like the guy who got 10,000.00 to fix the printing press, and he only turned one screw to fix it. Why did he charge so much? Because he's the only guy who knew which screw to turn. I think you get my point.

  I'd like to hear your thoughts on cam timing issues I've raised. I've not seen that discussed in consideration of advantages / disadvantages of fly removal. Steve

 

[Rembrant]

I would like you to clarify one thing for me though - everything I have read would indicate that flies in or out has zero effect at WOT, as the flies are WOT too. You point out a 15hp difference is achievable. do you know anyone who has used the same bike and the same dyno, and done back to back testing, flies vs no flies? I place no faith in different bikes / different dyno's as a tuning constant.

No, I don't know anybody that has done this back to back testing. I was merely comparing the data we have been seeing for years with these bikes. Flies out, PC5, exhaust, and dyno tuned, the C14 will usually hit 160HP with relative ease. The same bike, with flies in and off-the-shelf flashed ECU will usually dyno around 145HP. So, that's comparing not just the flies...but fueling also. Originally, a PC3/5 and flies out was THE mod to do to the C14...and they work very well like that. These days, it is common opinion that flies out is an "outdated mod" or more of a hack, and I don't really agree.

I've done lots of testing...not on a dyno, but road testing. Flies in, flies out, PC3 (on my 08) and PC5 (on my 2010), and I've done the ECU flashes with secondary fly mods as well. It is still my own opinion that these bikes work the best with the flies out. I just find that the throttle action, and low RPM acceleration is smoother with nothing but the throttle plates in there. The off-the-shelf ECU flashes are just fine...but I feel that they leave some power on the table that I personally would like to have. The power gains above 4-5000 RPM maybe be useless to some, but they're not to me.

I'd like to hear your thoughts on cam timing issues I've raised. I've not seen that discussed in consideration of advantages / disadvantages of fly removal. Steve

I don't know anything abut cam timing. My experience is mostly outside the engine...with controls. I have no experience with the flow of air into an engine...motorcycle or otherwise. (speaking specifically about the camshaft and valves).

Rem

[Steve in Sunny Fla]

Rem, so your experience is comparing flies out and refueled to the currently available reflash. i appreciate that. It still doesn't change my opinion, I still think a different reflash . carefully made, could outperform flies out. But that may not be the case, because I don't know, either, just suggesting there are other considerations that have been overlooked. Steve

[Rembrant]

It still doesn't change my opinion, I still think a different reflash . carefully made, could outperform flies out. But that may not be the case, because I don't know, either, just suggesting there are other considerations that have been overlooked. Steve

Steve,

I think a big issue is that there is a pretty small window where the secondary flies can be adjusted for optimization.

Since the secondary fly mechanism is used for the high idle, it can only be opened so early. If you try programming them to open too far below approximately 3000 RPM, you will run into problems with the linkage hitting the throttle. I've done it, and it was a bit unsettling at first. While the ramp open may be ok that low, it was the closing that was causing me trouble. If I closed my throttle too quickly, the secondary fly linkage was popping the throttle back open.

So, what you're left with is a window between approximately 2500 RPM and 4500 RPM. Above 4500 RPM, you're going to want the flies wide open, so there's really no tuning there.

What you're left with is a area of secondary fly action where you will want to adjust the opening "ramp". Closed is closed, and open is open, but what you can tune is how smoothly the transition is from one to another. As you know, when you twist the throttle on the C14, the big 1400 blows through that 2500-4500 RPM range like passing a fence post at 100 MPH. This is why I say it's a small window for tuning. When you're looking at the ECU's secondary fly map, there's approximately 14 columns for the entire 90 degrees of plate travel. When you break the graph down to show only the columns you can adjust between 3000-4500 RPM, you're not left with much adjustability.

In looking at a stock secondary fly map, you can see that Kawasaki has already provided the ramp...they just started it later. The tuners really just have to take the ramp, and bump it ahead in the RPM range. You can certainly try to improve upon it, like making the ramp steeper...so the secondary flies open faster, but in my experience opening them faster just makes the throttle action too choppy.

I think if the flies are left in place, you can more or less tune them so that they parallel the throttle plates in action up to approximately 4500 RPM, then program the flies to whack wide open to 100%. Once the throttle is beyond this point in the rev range, there's no worries of the secondary fly mechanism hitting the throttle linkage.

I'm not saying there are no improvements to be made in the secondary fly action...but I believe you'd struggle to make it better than the current aftermarket offering is. Just my 2 cents worth...anybody is more than welcome to correct me here.

Rem

[VirginiaJim]

I just ride my bike and not worry about it.

[martin_14]

I just ride my bike and not worry about it.

stop being peaceful 
 

seriously, Steve has a point regarding erg and valve crossing. I wish my brain was able to take a pick at such subjects without getting dizzy.

[VirginiaJim]

  Is this better?

[texrider]

The nanny throttle plates just soften and delay the motor hit, kind of protecting you from your own ham fisted self. 

[Steve in Sunny Fla]

let me offer another thought. Even BDF has stated many times that he noticed a notable increase in intake noise since removing the secondary flies. As far as I understand it, sound waves are pressure waves, and in this case coming back toward the rider or they wouldn't be noticeable. I think this clearly proves reversion waves are occuring in the intake track, and are stalled by the secondaries. Steve