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Discussion Starter #1
A buddy of mine has a 2009 zx-14 with a pcv with autotune,and ti-force full system.
Does anyone know the optimum a/f ratio #s 13/1 14/1 etc...
 

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13:1 is a pretty good starting point for WOT A/F on a NA bike. It's aggressive, but pretty good. I've personally seen pretty good results off the dyno (ie: at the strip) with A/F's in the 12.5-13.0 : 1 range. Please note that those are only for WOT... not part throttle #'s. :)
 

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Air fuel ratio?

to be safe 12.1:1-12.7:1 is slightly rich, i mean slightly. This way you wont burn holes in pistons. 14.1:1 is lean period. my dyno guy shut my run down at 9000 rpm's cause he didn't want me to blow my motor on the dyno. Google the word "stoicheometric" it is the optimum A/F ratio for an internal combustion engine. Then you can form your own opinion about what A/F ratio you want for your bike
 

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to be safe 12.1:1-12.7:1 is slightly rich, i mean slightly. This way you wont burn holes in pistons. 14.1:1 is lean period. my dyno guy shut my run down at 9000 rpm's cause he didn't want me to blow my motor on the dyno. Google the word "stoicheometric" it is the optimum A/F ratio for an internal combustion engine. Then you can form your own opinion about what A/F ratio you want for your bike
As a matter of fact, did YOU googled the word stoichiometric?
Do you know what the A/F ratio is at that point?
Is 14/1 leaner or richer than the stoichiometric A/F ratio?

Please, don´t get confused and translate that to other people and DO your homework first, rather than thinking you are correctly reproducing what your tuner said.

Best power ratio is around 12.7/1, but that ratio won´t give maximum achievable top speed. Going towards stoichiometric will.
 

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Best power ratio is around 12.7/1, but that ratio won´t give maximum achievable top speed. Going towards stoichiometric will.
.......I have to know how tuning OUTSIDE of the "best power ratio" will give more top speed?

Regardless, the bike in question will pull the stock gearing to the limiter (if it's unrestricted) all day long. Running the bike lean @ WOT on the rev limiter to get a mph or two that it has no gear for is, well, stupid.

Listen to Vince if not me... that guy knows what he's talking about. :thumbsup:
 

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Well... you´ve heard about flame speed?

You can achieve up to 10mph by leaning the last 800rpm. Of course, you don´t want to go further than 14.7 (and is useless and from that point onwards the engine is at risk)

The fast guys know this.
Perhaps you might want to give a try and you will notice that your bike goes far beyond that GPS # where it previously stuck.
You think 14.7 is risky.. ok try 14.

Again, no turbo motor.

The 08/09 10R with full exhaust (no PC3/V) is running pretty close to stoichiometric at WOT close to the rev limiter, and are doing GPS197mph with +1front/-1rear every day.

And...this is not a knowleadge contest. I know what Vince knows and he is right. What I said does not invalidate what he said, in fact I fully coincide.
I just added some point that is not usually given out. Take it or leave alone.
 

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stoicheometric is where it will get the best combustion and is a general term that changes with selected fuel use. methanol is around 6.4:1, ethanol is around 9:1, e85 ethanol is around 9.8:1 only problem is that most of us are using an A/F sensor that is calibrated to gasoline. best power usually occurs at around .88 to .89 lambda which on gasoline is around 13 to 1.(14.7 x .88) on e85 like I run in my gsxr .88 lambda is around 8.6 to 1 but will still read 13 to 1 on most a/f gauges because the gauge is taking the lambda reading from the sensor and converting it to an a/f for gasoline. some A/f meters allow you to change the fuel that it uses for its calculation. anyway enough of that, many things effect a/f so there is no right answer but from my time on the dyno I have found that a good place to start to tune to on pump gas and many of the VP race fuels is around 12.9-13:1. on e85 ethanol around 12.6-12.7:1. all of these readings are taken on an A/f meter calibrated for gasoline. 12:1 is way too rich and will probable cost the bike 10+ hp on a naturally aspirated engine. turbo and nitrous will be very happy and safe at 12:1 but not a NA engine. And also I have never seen a NA engine burn a hole in a piston because it was too lean, a nitrous or turbo engine yes but cant see it on a NA engine. your best bet is to take it to a compitant tuner and you will know its right.
 

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.....how am I (or this guy) going to get 10 more MPH on a bike that already hits the limiter in 6th gear... by leaning out the last 800 rpm?

I mean really... let's think about this: an extra 10mph --in addition- to the 190 or so my 06 does at sea level on stock gearing with a big tire on it (and it's still pulling into the limiter...). Leaning out my mixture a full point and a half would give me a 200+mph on a stock bike IF I did have the gear to get there? How much HP do you think that is that you're picking up by going lean like that? And is it honestly worth the risk/complication for a street driven vehicle that sees the limiter in 6th maybe a handful of times per year? That's just plain bullshit. Show me a dyno graph, or anything that coincides. All my graphs and real world testing show otherwise. I HAVE run it back-to-back AND on the dyno: the bike likes it fatter. It picks up 1/4mph and still pulls all the way through 6th. It sure as hell didn't pick up enough hp "in the last 800rpm" to go 10mph faster @ 190ish mph when it was lean. It didn't lose a damn bit of hp when we took it from 14.2 to 13.0... and it went faster in the 1/4 by 1-2mph at 12.5:1 vs 13:1 (dyno #'s, all those).... though I still don't know exactly why.

"The 08/09 10R with full exhaust (no PC3/V) is running pretty close to stoichiometric at WOT close to the rev limiter, and are doing GPS197mph with +1front/-1rear every day."
----show me the same run(s) with the A/F cranked down to the low 13 range and show me that it actually goes slower. I'd like to see that.

...and we're not talking about speed trials here anyway... we're talking about a good, strong, SAFE street AUTOTUNE that the guy can set his bike to and forget about. Even IF (big if here) you're right, it's about usless to this guy anyway. We can all appreciate some pedantic input/bench racing here and there, but this guy wanted some real world info... and it's just responsible to give advice to strangers with a safety margin added in. I sure don't want to be the guy that gave him the aggressive advice and he ends up fragging the top of the piston @ 170+mph because he had a bad load of pump gas. Common sense man.
 

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stoicheometric is where it will get the best combustion and is a general term that changes with selected fuel use. methanol is around 6.4:1, ethanol is around 9:1, e85 ethanol is around 9.8:1 only problem is that most of us are using an A/F sensor that is calibrated to gasoline. best power usually occurs at around .88 to .89 lambda which on gasoline is around 13 to 1.(14.7 x .88) on e85 like I run in my gsxr .88 lambda is around 8.6 to 1 but will still read 13 to 1 on most a/f gauges because the gauge is taking the lambda reading from the sensor and converting it to an a/f for gasoline. some A/f meters allow you to change the fuel that it uses for its calculation. anyway enough of that, many things effect a/f so there is no right answer but from my time on the dyno I have found that a good place to start to tune to on pump gas and many of the VP race fuels is around 12.9-13:1. on e85 ethanol around 12.6-12.7:1. all of these readings are taken on an A/f meter calibrated for gasoline. 12:1 is way too rich and will probable cost the bike 10+ hp on a naturally aspirated engine. turbo and nitrous will be very happy and safe at 12:1 but not a NA engine. your best bet is to take it to a compitant tuner and you will know its right.

That's awesome info Vince.... I didn't know that one about how they figured out the A/F for lambda. :) Maybe that's why Ivan likes runing CO2 readings instead of A/F, eh?
 

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That's awesome info Vince.... I didn't know that one about how they figured out the A/F for lambda. :) Maybe that's why Ivan likes runing CO2 readings instead of A/F, eh?
yep:thumbsup: But to the threadstarter though just tune it to 12.9 and you will be real close. If its a street bike you may want it a lot closer to stoich in the crusing areas of the map(part throttle) to save on fuel mileage but at 80-100% 12.9 will get you near right. :thumbsup:
 

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.....how am I (or this guy) going to get 10 more MPH on a bike that already hits the limiter in 6th gear... by leaning out the last 800 rpm?

I mean really... let's think about this: an extra 10mph --in addition- to the 190 or so my 06 does at sea level on stock gearing with a big tire on it (and it's still pulling into the limiter...). Leaning out my mixture a full point and a half would give me a 200+mph on a stock bike IF I did have the gear to get there? How much HP do you think that is that you're picking up by going lean like that? And is it honestly worth the risk/complication for a street driven vehicle that sees the limiter in 6th maybe a handful of times per year? That's just plain bullshit. Show me a dyno graph, or anything that coincides. All my graphs and real world testing show otherwise. I HAVE run it back-to-back AND on the dyno: the bike likes it fatter. It picks up 1/4mph and still pulls all the way through 6th. It sure as hell didn't pick up enough hp "in the last 800rpm" to go 10mph faster @ 190ish mph when it was lean. It didn't lose a damn bit of hp when we took it from 14.2 to 13.0... and it went faster in the 1/4 by 1-2mph at 12.5:1 vs 13:1 (dyno #'s, all those).... though I still don't know exactly why.

"The 08/09 10R with full exhaust (no PC3/V) is running pretty close to stoichiometric at WOT close to the rev limiter, and are doing GPS197mph with +1front/-1rear every day."
----show me the same run(s) with the A/F cranked down to the low 13 range and show me that it actually goes slower. I'd like to see that.

...and we're not talking about speed trials here anyway... we're talking about a good, strong, SAFE street AUTOTUNE that the guy can set his bike to and forget about. Even IF (big if here) you're right, it's about usless to this guy anyway. We can all appreciate some pedantic input/bench racing here and there, but this guy wanted some real world info... and it's just responsible to give advice to strangers with a safety margin added in. I sure don't want to be the guy that gave him the aggressive advice and he ends up fragging the top of the piston @ 170+mph because he had a bad load of pump gas. Common sense man.
:crackup: I don´t have to tell you forget everything I said.

Perhaps if you read this comment of mine that seems ridiculous to you from another member, you will take it into account.

Just to extend a little bit more the topic, you can´t see the advantage of this A/F ratio on the dyno.
As a matter of fact you can probably see a very slight drop in power, but as the bike is accelerating on the dyno (as it does in the 1/4 mile) you´ll need a fatter ratio to show best power (and accelerate faster).
Once acceleration is not necessary (at 190mph) you can take advantage of the faster flame front inside the combustion chamber, of leaner ratios.
Fatter ratios achieve good power and best acceleration times, but not best top speed.

Then, if you´re hitting the limiter in 6th, continue to drop teeth at the rear until you don´t anymore.
Best 2nd gens here are doing are doing GPS 198mph without internal engine work. You may think that this is pure :bs:, but it´s not. (about the same the 3rd gen does without Pcommander)
08-09 GSXR1K are doing GPS 203mph without the hell of a work.
In every case lambda sensors showing around .76 / .75V close to rev. limiter.

That means something is being done right down here, and in no case, as I consider myself not to be any kind of moron, I will throw here some false info (not even "in doubt" info)

As Vince says, best power is get from a .86V lambda reading. Completely agree with that and the rest you said Vince. Really good post.:thumbsup:
 

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:crackup: I don´t have to tell you forget everything I said.

Perhaps if you read this comment of mine that seems ridiculous to you from another member, you will take it into account.

Just to extend a little bit more the topic, you can´t see the advantage of this A/F ratio on the dyno.
As a matter of fact you can probably see a very slight drop in power, but as the bike is accelerating on the dyno (as it does in the 1/4 mile) you´ll need a fatter ratio to show best power (and accelerate faster).
Once acceleration is not necessary (at 190mph) you can take advantage of the faster flame front inside the combustion chamber, of leaner ratios.
Fatter ratios achieve good power and best acceleration times, but not best top speed.

Then, if you´re hitting the limiter in 6th, continue to drop teeth at the rear until you don´t anymore.
Best 2nd gens here are doing are doing GPS 198mph without internal engine work. You may think that this is pure :bs:, but it´s not. (about the same the 3rd gen does without Pcommander)
08-09 GSXR1K are doing GPS 203mph without the hell of a work.
In every case lambda sensors showing around .76 / .75V close to rev. limiter.

That means something is being done right down here, and in no case, as I consider myself not to be any kind of moron, I will throw here some false info (not even "in doubt" info)

As Vince says, best power is get from a .86V lambda reading. Completely agree with that and the rest you said Vince. Really good post.:thumbsup:
I cant chime in on what you said because I dont do that kind of racing and I have never tried to lean a motor out that much on top because as you said in drag racing the top end extra speed is not needed. also did you mean .96 and .95v lambda in this post? .76 is very rich not lean??? :thumbsup:
 

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Discussion Starter #15
autotune #s

My buddy with the 09` zx14 just finished riding/auto tunning his zx-14,so we opened up his pcv with my labtop to take a look at the a/f #s the auto tune gave,they ranged from 13.4 to 13 all across the map.The 80-100 columns were 13.
We also did a few roll ons 40mph-120ish,and the auto tune really made a big difference in his mid-range,for the first ever I had to catch him and i did right around 80-90mph.
 

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:crackup: I don´t have to tell you forget everything I said.
Eh, if that's the way it is then. If you have something that works really well in what you do, by all means go for it. :thumbsup: It's apparently a highly-specialized area... the exception that proves the rule, as it is. :)

Back on topic: Good to hear the autotune works well... I've been waiting for some good reviews/info on the set-up. :)
 

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I cant chime in on what you said because I dont do that kind of racing and I have never tried to lean a motor out that much on top because as you said in drag racing the top end extra speed is not needed. also did you mean .96 and .95v lambda in this post? .76 is very rich not lean??? :thumbsup:
Vince, I mean reading the lambda sensor with a digital voltmeter.
I´m sure you´re saying the lambda factor. At .8x the lambda factor aprox equals the same figure in output voltage (.8x volts)
Towards 0 volts is the lean side, and towards 1 volt to the rich one.
.75 volts is towards the stoich ratio.

I´ve search the internet for a conversion table (lambda output voltage vs A/F ratio) that I do not have right now in this computer and found this kinda poor graphics..
 

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Vince, I mean reading the lambda sensor with a digital voltmeter.
I´m sure you´re saying the lambda factor. At .8x the lambda factor aprox equals the same figure in output voltage (.8x volts)
Towards 0 volts is the lean side, and towards 1 volt to the rich one.
.75 volts is towards the stoich ratio.

I´ve search the internet for a conversion table (lambda output voltage vs A/F ratio) that I do not have right now in this computer and found this kinda poor graphics..
:thumbsup: OK I was thinking lambda not actual voltage from the sensor. I have this chart it may help some others figure out what we are talking about: range is voltage at the sensor:

Range-------Lambda---- Air/Fuel Ratio-------Output Torque-----Observations

>945mV -------- <0.80----- <12 -------------- <98%----Too rich, power loss
900-945 mV----- ~0.85 -----12.5-------------- 100%----Maximum power
855-900 mV -----~0.90 ----~13.2 ------------ 99% ----Good operation
810-855 mV------~0.93------13.8--------------- 98% ----Good operation
540-810 mV------~0.97 -----14.3 -------------- 98% ----Good operation
225-540 mV--------0.98-----14.4 ---------------97%-----Good operation
180-225 mV--------1.0------14.7 ---------------97%-----Good operation
135-180 mV--------1.02-----15 -----------------96%-----Good operation
90-135 mV---------1.04 -----15.3----------------95%-----Maximum economy
45-90 mV--------1.05-1.25---15.4-18-----------74-94%----Pretty lean
<45 mV----------->1.25------->18 -----------------? -----Too lean, misfires
 

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:thumbsup: OK I was thinking lambda not actual voltage from the sensor. I have this chart it may help some others figure out what we are talking about: range is voltage at the sensor:
So tuning a bike in accordance with that chart would make for good street riding? Run 14.5-15:1 for say anything under 20% throttle, and I've always thought to tune to 12.6-13.1 for optimum power so would this work Vince?

You guys have all brought some awesome information into this thread, thank you all of ya.

sextaafondo, how the hell you getting past those speed limiters?:lol:
 
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