Secondary Butterflies removal review

[bradbusa]

ok, here's a few pages i scanned over from when we were learning about induction tuning for specific power band and the benefits/affects certain techniques provide.

slide 9 on the first scan talks about throttle body design and construction.

the 2nd scan explains the benefits behind tuning the intake for specific rpm ranges.
longer, smaller diameter runners is similar to our engines when the STP are partially closed. same effect.
larger, shorter diameter runners is what our engines actually have. better high rpm operation.
the STP just simulates smaller diameter by limiting the volume of air flowing into the engine.

the 3rd scan discusses air intake velocity.

basically this all explains in detail that it is possible to tune an engine for peak power in specific areas (high rpm operation vs. lower rpm operation.)
manufacturers are able to get the best of both worlds by using STP, variable length intake ducts, or exhaust valves..
this keeps velocity high at lower engine speeds, and opens to allow more volume at high engine speeds, when velocity is already maintained by piston speed.

hope this makes sense

 

[sixpack577]

I think for agressive riding, the secondaries removed is a gain un tuned, and a bigger gain with a proper dyno tune.
And no gain to those who don't like it.
There...Does that settle things?

 

[bradbusa]

good enough for me man!

 

[sixpack577]

I have a gutted converter, cut the mufflers in half(just one chamber now instead of three) a K&N air filter, and obviosly the STPs are gone in my 08, I even have ran Royal Purple since 2500miles, now it's at about 10k. The bike is not tuned. Ooooh, what awesome mods I will have it dynoed with ECU Editor when cash allows. Will it run better then? Of course, it is flowing more air now than the stock tune can provide fuel for.
Have I leaned out the engine? after at least 5k miles, not according to the sparkplugs, engine performance, and yes, even exhaust smell.
Have I lost horsepower and torque with my current set up? At certain rpm's, yes. Have I gained any hp and torque? Maybe a small amount at certain rpm's. Did the power curve in 1st, 2nd, and 3rd gears become less linear(great description in a previous post)? Yes, it now comes on harder, much like an opening 4 barrel carburetor. Did the higher gears change? I'm sure, but I'm either cruising in them, or at wide open throttle. The on the roll acceleration in those gears at 4k to 5k still feels very responsive and impressive.
And most important of all, Do I like the ride and feel of how the engine flows this way? Yes, much better than the way it was stock. It's a preference, and I respect the opinion of those who don't prefer it.
It suits my wants and needs until I have a better exhaust and a dyno tune. Yes, this a compilation of all my posts This a topic I found months ago that was posted by what I feel where very intellegant people. I have searched, but cannot find the posts, and therefor the folks to give credit to. I started a thread again after trying it, because I liked the results. Then Dozer started this thread posting his results. Which I feel are very similiar, and that it's not his current prefernce. I think he got a great thing going here again, some obviously very sharp folks have continued to comment and help revive this thread. Neither side of the discussion is wrong, we just have different preferences.
It seems to have come to a concensus that with the STP's removed and all the great work being done by many on the ECU Editor; that properly tuned for certain riding styles it is beneficial to have them removed. And again we wait and hope for before and after dyno tuning in multiple gear results. Posted maps and showing the graphs with the changes in power curves before and after.
I hope that this post has encouraged someone able to this to do so, and maybe even soon. Until then, there's not much left to discuss. Ramble over Thanks

 

[mungybear]

richard ironically enough 1st gear isn't really limited, its just 2nd and 3rd,

gears 1,4,5,6 and pretty much the same regarding stp opening at WOT

this is what i thought when i bought my 1st gen 2!!! Always ending up using 4th gear to overtake. That's not right is it?


So to correct this Greg, I open advance settings and match gears 2 & 3 to the settings (both stp and fuel???) of the other gears and flash? Please correct me if i'm wrong.

 

[jeepinocala]

ok, here's a few pages i scanned over from when we were learning about induction tuning for specific power band and the benefits/affects certain techniques provide.

slide 9 on the first scan talks about throttle body design and construction.

the 2nd scan explains the benefits behind tuning the intake for specific rpm ranges.
longer, smaller diameter runners is similar to our engines when the STP are partially closed. same effect.
larger, shorter diameter runners is what our engines actually have. better high rpm operation.
the STP just simulates smaller diameter by limiting the volume of air flowing into the engine.

the 3rd scan discusses air intake velocity.

basically this all explains in detail that it is possible to tune an engine for peak power in specific areas (high rpm operation vs. lower rpm operation.)
manufacturers are able to get the best of both worlds by using STP, variable length intake ducts, or exhaust valves..
this keeps velocity high at lower engine speeds, and opens to allow more volume at high engine speeds, when velocity is already maintained by piston speed.

hope this makes sense

This goes back to what I wrote earlier it is faster better and cleaner with them on I love it when people who have no clue to engineering think they can make it better by taking parts off a machine that is engineered for its best performance It reminds me of that poor guy who posted last night of the aftermarket links he put in the rear swing arm of his bike and crashed because they folded up wonder why Look people when things are engineered for their best the only whay to make them faster is to either lighten them up or start replacing parts well or add juice like me

 

[POWERHOUSE]

This goes back to what I wrote earlier it is faster better and cleaner with them on I love it when people who have no clue to engineering think they can make it better by taking parts off a machine that is engineered for its best performance It reminds me of that poor guy who posted last night of the aftermarket links he put in the rear swing arm of his bike and crashed because they folded up wonder why Look people when things are engineered for their best the only whay to make them faster is to either lighten them up or start replacing parts well or add juice like me

And I love it when people make uninformed comments and just accept what is placed in front of them no questions asked . . . I am one of those who advocates removing the butterflies - guess what? I have an engineering background, and am a mechanical engineer by trade. So I guess I am one of those who has no clue about engineering. I am also an engine builder, drag racer, dyno tuner . . . and I have done cylinder head porting for years. Building horsepower is something I have done for over 35 years.

Please realize that not everyone on this board is ignorant. Know that there are many people here with extensive backgrounds, and understand that people have different opinions. Try to express yours without insulting the opinions of others, which, by the way, may be informed opinions.

To say that people who have done this mod with great results have no clue is wrong . . . I respect your opinion, even though it differs from mine. I have done this mod, along with fuel adjustments, and have had nothing but improvements in performance.

Apology accepted!

 

[fallenarch]

Can't believe there aren't drag racers on here that really know the scientific pluses and minuses of this mod. Come on guys, someone must have tried this and dynoed it to get a real idea of it's value.

I personally don't think it is a performance enhancement but I base that on my limited knowledge and will be the first to admit I could be wrong.....

 

[Amode]

This is still going on Interesting. Petrix should know how the the STP work. Weather they are tied into the secondary injectors. Just got back from reno 6 to 9 thousand feet. Nothing runs up there the cows move so slow they get fat no air. It pops now and then, one time with just a little throttle it wanted to quit. Back at 2 thousand feet and below no problems. It does not matter what you have tuned they are all different. I think i will call frank and talk to him i have changed every thing in the ECU. Almost every time i ride i change stuff to see what works all kind of maps.

 

[Amode]

Well let me tell you all something about this STP stuff. This is not new tech. This has been around since about the 70's in the carb's. It has never worked removing the SPT's in the Vacume deal. Vacume Deal Got it. I have worked a great deal on timming, fuel, Stp settings. I have a theory take no prisoners, (Burnt Pistons). I have a lot of fuel, timmining, STP openings. And more to come. I have tryed it all since i got the ECU Editor. Ask me what does work and what does not. I would like to ride with some one who thinks he has a Stock Fast Busa and been on a Dyno. Until then Dream on. The Front office is 6'1. If all the great tuners seen my maps they would ****, And say that won't work.

 

[mountainmotor]

I personally don't think it is a performance enhancement but I base that on my limited knowledge and will be the first to admit I could be wrong.....

Talking street bikes. This secondary throttle design is nothing new. Suzuki first used it on the 2000 year model GSX-R750 . Don't know what all the fuss is about. If your a canyon carver and get caught down in second or other gear at low rpm having to dig it on out of the corner , you'll want to leave the system as is. Same for roll on's in higher gears where it also works well.

The ports are big and the exhaust cam is in at a relative high centerline. Thats the recipe for a low velocity, lower rpm dud . Suzuki helped to make the best of both worlds with the addition of this on the second generation 1340 streetbike and was able to ditch the flapper valve* the first gen Busa used at same time.

* EPA noise

All out drag racer or blowing through the TB's with a turbo will be a different story perhaps but i've seen little evidence over the years to convince me to remove the secondary plates on my Suzuki street bike.

 

[mountainmotor]

These two links should help understand why the first gen Busa used such long center velocity stacks and more about the secondary system. It's dated info but if you were riding/racing Suzuki's back then you can see where the Gen 1 Busa could have been updated way back in 2001-2003.

Suzuki GSX-R 1000 in detail - Page 1

Gsxr 750 k1 2001

 

[2Wheels2Live]

I know that removing the secondaries on the 06-07 zx14 made a HUGE difference for the better. I felt it first hand on my 07 before and after with a properly mapped power commander. It went from a dog below 5500 rpm to a stump pulling, tire spinning wheelie monster from 3000 rpm on up Not a single downside of any kind to that mod ANYWHERE I'm not sure why the busa's secondaries would be that much different? Same basic set-up and idea I believe?

 

[bradbusa]

it all has to do with throttle bore size. if you tune them for high rpm(like the gen2 busa) the throttle bodies are as big as they need to be to feed all the air that bike can move while approaching redline.
wide open throttle bodies are not the best thing however at lower/midrange rpms. this allows a larger amount of air volume than is required by an engine cruising around 3-7k rpms(midrange). hence the STP to maintain air velocity. it doesnt hurt low end grunt, it helps it in our case.

if the TB were tuned to flow best for midrange grunt, the upper rpm range would suffer dramatically. enter the STP.. best of both worlds. maintain air speed when ram air isnt available, and open to allow max volume for high rpm.

in the case of zx13.5 it sounds like they just restricted airflow for whatever reason.. who knows. kawi does weird shiz.

of course, when accompanied with tuning, adjustments to the STP opening ratio will result in great benefit to power output.

 

[BusaDudeBrazil]

After riding my Gen II with the secondaries off for two weeks now, dyno pulls before and after with negligible differences in the power curve and a lot of real world tests, I can honestly say this:

- dyno pulls showed negligible top end power and power curve differences, but they were done in 4th gear (where we believe STP would be 94% open by definition of the ECU settings, did not have a chance to do more dyno pulls on other gears)
- roll ons take a little longer and you can tell the difference the air enters the engine by the way it breathes, the air intake velocity theory is absolutely true, I am now a firm believer in this theory and if you are not gearing race like it takes away some of the grunt the bike has in upper gears and low rpm - not worth if you are just road cruising in 6th most of the time
- HOWEVER, HOWEVER AND HOWEVER, and this is why I LOVED it and will keep mine off, when gearing race like, the bike pulls so much harder that it is hard to believe a simple mod like this can result in such a tremendous difference in performance, it will wheelie so easy in 1st, 2nd and third if you really go at it, AND it will leave other STP on Busas behind easily (even though one can argue that wheelies are not a direct indication of performance increase and the STP on Busas can also wheelie).
- its MUCH, MUCH more of a pleasure to ride now that the way the throttle feedback is so much crispier and instantaneous

With all of that said, I think everyone should try the bike with the secondaries off and see for themselves if they like it that way or not - mine now is unbeatable for the other Gen II I ride with when WOT´ing, it really gets everyone´s attention to get to ask what I´ve done to the bike to make it that way.

I can only hope that the next Gen Busa brings another generation of STP that do not take away throttle crispness and power when you love it most, when you are really going at it.

Hope this helps!

 

[mungybear]

which is why i asked cant you just edit it out in petricks editor to match the other gears. This is the exact alternative surley????
Posted via Mobile Device

 

[BusaDudeBrazil]

which is why i asked cant you just edit it out in petricks editor to match the other gears. This is the exact alternative surley????
Posted via Mobile Device

That is where the trick is, my .02 cents.

I think that even at 94% open, the physical size of the secondary plates makes the air flow slower than without it, with less volume at high revs.

In mode A it is supposed to be wide open from 6k on and I can tell a big difference without them on even on these conditions.

 

[fallenarch]

None of this really makes sense to me. The secondaries definitely reduce air volume in the throttle bodies at lower rpm's, which increases velocity. That means removing them would cause a sort of "bogging" at lower rpm/throttle settings, reducing power and grunt.

When the secondaries open, the plate takes up no more area in the throttle body then the shaft does, so if you remove the secondary plates but leave the shaft there is essentially no change. It the plates are causing turbulance, that would theoretically be a good thing.

So, unless you go to special throttle bodies that don't have the secondary shaft obstruction and are flowed to actually be aerodynamically more efficient, there is really no difference in the top end performance with the secondaries in or out.

So, nothing I have heard or read on intake/injector design supports a performance increase by removing the secondaries for a bike like the Busa that is optimized for top end power then "compensated" for low end performance. My feelings are that the increased growl from the intake stacks caused by the secondaries being out is making people think the bike is doing more than it really is.

Again, if someone would be kind enough to dyno this and post the graphs I would believe it was an improvement.

 

[2Wheels2Live]

I'm also wondering, I have a first gen busa without secondary throttle plates, and I have instantaneous throttle response at all rpms's, with massive low end, and tons of top end. I actually read in a motorcycle mag when the 2nd gen came out, and they tested it back to back with a first gen, that most of the testers felt the first gen had more low end snap. Does anyone know why exactly suzuki went with the secondary throttle plate set-up? Whats the supposed benefits? On the zx14, the rumour was the secondaries were there to "soften" the power delivery and protect us from ourselves. On the 08 and up 14 they dramatically increased the opening speed of the secondaries and gave it much more low end...which kinda says maybe it was a safety thing? I wonder if thats the purpose of the gen2 busa's secondaries as well? If I had one I'd pull those babies out too I like a sharp, crisp right NOW throttle...not a softened up "protect me" throttle. Where's the fun in that?

 

[POWERHOUSE]

Gen 1 Busa: 46mm throttle bodies, no secondary throttle plates;

Gen 2: Bigger motor, more compression, better flowing head, SMALLER (44mm) throttle bodies, secondary throttle plates.

ZX14: 44mm throttle bodies, secondary plates.

The ZX14 keeps its STPs closed up to 6,000 rpm at 100% throttle, which is why removing them shows clear gains on wide open dyno pulls;

The Gen 2 only keeps them closed in 2nd and 3rd gear, which is why it does not show up on wide open throttle pulls on the dyno.

To say that the Gen 2 cannot handle its "big" throttle bodies, and the STPs are there to increase velocity and help the motor transition is ridiculous, since the Gen 1 has bigger throttle bodies and has no problem, even with a smaller motor, lower compression, and its early cylinder head. Again, removing the STPs requires remapping on both the Gen 2 and ZX14 in order to realize the gains. I haven't tried this on either bike with stock pipes, and am not sure I would recommend it.

We would need 3rd gear runs with a Gen 2 on a dyno to see the differences.

Do the math . . .