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Posts posted by moto
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Right, but this is when no oxygen is left over whatsoever, and an engine will rich misfire before no oxygen is left (remember 0.2% O2 with a CO of 12.6%). At that point of course there will be a whole bunch of oxygen left over, which will prompt the ECU/autotuning software/Wideband Commander/tuner who is not paying attention to add even more fuel.Hi Derek,
Don't forget that the WBO2 sensor under rich conditions is actually measuring CO and HC and relying on equations to estimate the air to fuel ratio.
Regards,
Derek
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You can record all of the stuff with the VDSTS untill the cows come home, and the limitations of using an O2 sensor and the fact that you cannot measure horsepower and cannot put a steady load on the engine will prevent you from getting results as good as possible on a proper dyno. Once again, I can test any and all throttle position/rpm combinations one would ever encounter on the street (and some one would never) with step testing. The rate of throttle opening makes very little difference on an injected engine. Think of it this way: At any given time there will be a certain MAP, TP and rpm. If you tune for all of them to be correct, it does not matter at what rate the ECU is moving around between cells. Certainly, you will not be able to get useful information from an O2 sensor under the transient conditions of a moving throttle.As I said, the RPM, throttle position in degrees, ignition timing, Spark advance , Oil temprature,air temprature, battery V., Atm pressure, and a bunch of other parameters if I need are recordered in REAL time riding the bike directly from the OBD of the ECU to the VDSTS software on my PC.
These are the measurments we are talking about, and to these measurments different throttle openings from the same rpm , represent different throttle position degree opening . i.e. a fast snap on the throtle- roll on on 3rd gear at , i.e 3000rpm to 4.200 rpm would have totally different opening in degrees of the ''butterflies'' of the TBs
( T.P. degrees) compared to a slower opening in all rpm in between , therefore different injection timing , soark, fuel, ect.ect.
As well as the AFR from innovate is also as well logged in another log file.
I think we might, as I sometimes have trouble following you, and you sometimes have a hard time following me. Certainly, we would have to repeat ourselves a lot less if we didn't.No we don't have a language problem
These folks and I are in agreement on all points.SO here it is, and so it is in their own words ,http://www.awe-tuning.com/pages/faq/awefaq_main.cfm?FAQ=22
Taken from the above page , also more about Dynos and how-what they measure
I never said that I didn't think temperture had an effect on anything. What I did say is that for me to maintain temperatures accurately is not a problem. I am able see changes that result in as little as .1 to .2 hp on my dyno. This would simply not be possible if the temps were not controlled closely enough.Temperature: engine temp *greatly* affects power output. Dyno runs done during different levels of coolant, engine and oil temps will have drastically different results, with the cooler runs typically producing more power. Some engines, such as the forced induction vehicles, can lose up to 15% of total hp and torque as temps rise. Thus a colder run done after a particular mod will exaggerate gains, if any. Redirecting external cooling fan air can have tangible effects on data, especially when air is concentrated on intercoolers, open air filters, etc. The best dyno operators will use high velocity fans (not just high volume fans) directed at critical areas of the engine and drivetrain in order to mimic real world conditions as much as possible
Let's start from the beginning:I have never imagined a more accurate system for AFR than the innovate LC-1 with XD-16 and the Bosch LSU4 Wideband sensor. The immediate responce on what my engine is doing is awesome.My engine runs healthier than ever because of their assit to the maps I do.Under perfect conditions (i.e. 100% efficiency), there is some amount of oxygen required to burn a known quantity of fuel with no leftovers. Unfortunately, 100% efficiency only occurs under the controlled conditions of a laboratory experiment. There must then be some "average" combustion engine efficiency that is used to calculate "A/F ratio" from oxygen content. So, we've arrived at the first problem: There is no direct correspondence between oxygen (or any other gas) content and "A/F ratio". Second, the ideal "A/F ratio" varies from engine to engine and from one rpm/throttle position/load combination to another. Imagine we equip a vehicle with a fuel flow meter and a mass airflow sensor. We then add or subtract fuel so that we have a stoichiometric mixture (as evidenced by the fuel flow and air mass measurements) at a particular chosen throttle position/rpm. We then screw a wideband "lambda sensor" into the exhaust. Do you think it will show a lambda value of 1.0? We then tailor the amount of fuel to yield some desired BSFC or HP. Do you think the A/F ratio as measured by our fuel flow meter/mass air flow sensor combo and our "lambda sensor" will match, or even be offset by the same amount? Say we try this experiment at a different throttle position/rpm. Do you think the results will match, or the offset from the previous comparison will be predictable, and therefore transferable to other throttle positions/rpm? Say we map this all out so that we know what these values are at all throttle positions/rpm. Will it carry over to another engine of the same model? And what if there have been modifications? Third, I'd like to consider what the goal of tuning is in the first place. Is it to get a particular "A/F ratio"? It's more likely that we would like the engine to make horsepower and be efficient (i.e. get good mileage). Looking at oxygen content has limited use when trying to achieve these ends. However, don't get me wrong, oxygen measurements are actually good for something. Once you have tuned for max power by adding and subtracting fuel, the oxygen numbers can help you to detect a retarded ignition timing, misfire, or stagger issue (all of these produce an excess of O2). If you go straight to a particular oxygen content, you completely ignore these factors. Even once you've corrected these, the oxygen content can still vary substantially (somewhere between .1% to 4%). So it can often help to point you in the right direction, but isn't the final arbiter of anything. CO on the other hand can, once a proper value has been established through bracketing, be used throughout as a target to set the mixture strength close to optimum for power and mileage. CO is also not the final arbiter of anything, but it tells you much, much more about whether an engines map is in the ballpark than O2. You can hit an oxygen target right off the bat while the engine has the completely wrong amount of fuel, a misfire and/or wrong timing, whereas with CO, fuel will be close, guaranteed. As an example, there are spots on two Aprilia Futura dyno charts I have, where the O2 content is 0.2%. One has a CO of 12.6% (this is drowning rich!) and the other has a CO of 3.2% (perfect at this particular throttle position/rpm combination). With 3 to 5% CO being a good range for most motorcycle engines, I'm sure you can draw your own conclusions from this example. Then there are all of the sensor/controller related issues, such as that abrupt changes in probe temperature (on off throttle transitions for instance), minute changes in voltage/voltage offset (turning lights/accessories on and off, changes in charging voltage due to rpm), and changes in exhaust pressure (again on off throttle transitions for instance), will cause inaccurate readings. There has been some work done to minimize these and other errors with sophisticated controller technology and careful calibration/setup. See http://www.bgsoflex.com/pwb/0.95/PWBV0.95_QandA.pdf and http://www.techedge.com.au/vehicle/wbo2/wblambda.htm. I think very few if any readily available WBO2 sensor/controller combos manage all of these factors effectively, and even if they did, that still leaves the inherent unsuitability of O2 by itself for determining suitable mixture strength. Then there are the delay problems, which will vary fairly unpredictably, or else one could just build an appropriate time offset into the controller, logger or ECU. These delay problems mean that an O2 sensor can only really be used to tweak a map at steady throttle and rpm. Unfortunately, this also means that it can't be used when the engine is really making power (unless you are going up hill with a head-wind). So-called closed loop ECUs either only tweak a setting after the engine has been at steady state for a while, confine inputs from an O2 sensor to a narrow band of rpm/throttle positions, or both. Most ECUs that use O2 sensors do so not to keep the engine running at peak efficiency, but to keep a cat functioning properly. If you insist on trying to use an O2 sensor for tuning, you still need to come up with proper sensor target voltages. These targets would be developed by seeing what values exist at peak HP or best BSFC at each breakpoint. But by then, you already have a perfect open loop map that stands to be harmed more than helped by O2 sensor inputs. I've heard people argue that you can use an O2 sensor to build a map that is in the ballpark when you are starting from scratch. Even that is not possible, as the ECU will get similar input regardless of whether an excess of O2 is due to too little fuel or due to too much.
Further recommended reading:
Motorcycle Fuel Injection Handbook
http://www.factorypro.com/dyno/4gasEGAvso2sensor.html
Certainly, the cat will change the readings (after all that's what it's designed to do), and on vehicles equipped with them I install a bung ahead of the cat to take readings from. Why would measuring at the exhaust end be "a great mistake" on non cat equipped engines? Are you thinking that reversion would introduce outside air? If so, not to worry, as I use a probe that sticks up to 30" (760mm) into the exhaust.Measuring at the exaust end is a great mistake, the data taken will be missleading especialy in catalitic vehicles.
Again, how can not allowing the engine to accelerate at all fail to be enough resistance? How can maintaining the engine precisely at whatever temperature you like not be good enough?Now ,since the Dyno is just a simmulation of real time conditions (IF then again it is perfectlly tunned for that.)with the sertain lack of having true drag resistance and real life air cooling on the engine it isn' enough , perhaps good , but not enough for me.
Now you are really confusing me. You say that a dyno is not good enough for you, and then say that yours and others subjective opinions are. That seems totally backwards to me.Personally I trust what I get, and my motor runs best when adjusted to the sertain AFR area I target , and I really don't give a damn about what's the HP it can turn out on a dyno , all I see is that it's pulling like a freight train at any time I want in all real life driving and these are the results that matter to me., and that Mandello mechanic who drove it also confirmed ''the most lively 1100i Sport I have driven.'' well, all these are enough for me.Regards,
Derek
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OK, so what measurements are we talking about then?Nope that has nothing to do with any O2 sensor , These are measurments taken directly from the ECU OBD with the VDSTS diagnostic .
And ohh I think I have to tell you that My bike never had or any kind of O2 controler , or kat, or whatever to interfere it's ECU.
My ECU is OPEN loop . and NO sencor is controling anything(= free and easy).
It's just another way of saying that just because a certain number of people believe something doesn't make that true, and that just because a certain number of people do something doesn't mean you have to do it too.I don't think they are talking about that here.
I thought you were saying that the cylinder head or oil temperatures encountered while riding around would not be as low while on the dyno, because there is not likely to be sufficient air speed over the bike. I was pointing out how this is not necessarily a factor when step testing, and why.I don't understand this.
I think we may have a language barrier here, as now I'm having trouble following.Nevertheless I wanted to pinpoint the differet temps in real life and how these can be calculated in tuning generally from a Load dyno- approach (of best power standard)
What I am saying is that I consider O2 sensor derived AFR to be essentially useless, no matter if monitored on the street or on the dyno.I think we are talking the same thing, and my meaning from the begining was the same , that you can't be based on AFR to tune on a Dyno = Dyno+AFR don't match as, AFR+ Street.
I have not yet seen any measurable differences in exhaust gas content from one temp to another on a injected bike. I think I have either not tested across a broad enough range in terms of conditions, or simply gotten lucky in that the existing corrections were actually pretty good.I think I do it the hard way, but I asked you a different thing, if you have 'tickled' any of these stuff or measured differences in colder (yet acceptable to ride9 and hotter engine situations (and or whether)and if any action took part.
Unfortunately, the results achievable on a brake dyno with 4- or 5 gas EGA will be essentailly impossible to duplicate on the street with O2 sensor derived AFR.It would be usefull to say that , there are dynos and Dynos , and mechanics and Mechanics, and it's not wether is Dyno or street+AFR better, but the target-result on these from the tunner.
Regards,
Derek
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With my dyno in step test mode, the engine is held at a constant rpm and not allowed to accelerate at all.Quote 4= Perhaps air resistance-drag above 100mp/h (OK that's too small letters perhaps that play smal role ?
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This could be because cells adjacent to each other may not all be tuned correctly, and because of the inherent limitations of an O2 sensor.Quote5= I say what I see on my diagnostic mesurments of the ECU data on the street. Can drop you a log file for the VDSTS (if you work with VDSTS-won't open any else) to see what I mean.
Agreed. Higher resolution is better.2,
Yes that's what I mean , the 27C512 of IAW16M has 18 rows (TBs) in 16 different RPM points. If, i.e. it had 32 in 24 repsectively a more smooth approach could be taken.
Put the thing on a brake dyno with a 4 or 5 gas EGA.but then what could one rely upon and take it from there,?
Technically, this is synonymous with "mediator". In this context one could substitute "determiner".(what is the ''arbiter''?)
If a bunch of peple jumped off a cliff, would you?I would add though that, lots of relative in tunning people can agree with my approach here(concerning the AFR).
Certainly, but there are more and less effective approaches.For sure there can be different approaches to the same subject as well,.
Agreed, except in most cases the dyno is a more accurate instrument than perception.Quote=8 I do so, actually I don't trust things , until their value is proven, for that fact I first notice the effect and then look at the numbers if they match then I trust. Difference can be noticed easy ,by instaling other chips with their strange bahaviour and then ,switch on something (supposingly) better, if it is(without any readings) then it is, and the readings are then taken to concideration.
With step testing, the airspeed only needs to be enough to allow a step to be initiated and ended with a reasonable and repeatable beginning and ending engine temp.a) where did the cooling came from? (O.K. the air blowing at the engine,) Does this amount air to speed exist on the Dyno?
In my opinion, you would have to independently control oil and air temp on a brake dyno with 4- or 5 gas EGA to properly tune the compensation tables. Is this compestation difference in the oil temp a bit too big? ....O.K. you got me here too, it depends the compestation of the air temp at that point...but? is it then a bit big , won't it make a difference in the fuel burning and ect.ect.ect. of the bike? (measuring AFR there is a difference shown in the situations.)If I immediatelly stop the bike with this colder oil temp the reading would be different in same slower riding as before 10 minutes or so-not much but some.
Anyways tell me your opinion in based on your methods and experience. And if you have 'messed' around with other Guzzis map temps It would be interesting to know your findings in the subject
Regards,
Derek
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There is absolutely no reason why an engine should not run right when it comes off the dyno, unless it was tuned to an "AF ratio" instead of to best power, BSFC, or even a CO between 3 and 5%, or unless certain breakpoints were neglected.When we were done with the Dyno, there were signifant (to me) area's of lurching or lulls mostly noticed at accelerating up to highway speeds from a stop or on-ramp. Also I had one area where if I was chugging along at maybe 35 mph but in a gear to have the engine above 3000 rpm... you know those straight aways just before the twisties... if I backed off the throttle, just a little, it would actually accelerate. Oops.. Nothing drastic, I'm sensative to it, but it didn't help engine braking I can tell ya that.
Anyway, those are some things to watch for and reason to not rely on just the Dyno machine to tune your bike. Ride it too. I'm not saying anyone isn't doing this here, but I have certainly seen it enough times. People roll the bike off the Dyno, and as long as it doesn't stall or backfire too badly they are done. If you are going to go through the trouble of doing it.... do it right is my opinion.Regards,
Derek
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Not this again...Have you measured the AFR (Air Fuel Ratio) between the different tweaks you did?
My dyno creates whatever load is necessary to to hold an engine at whatever rpm in whatever gear and at whatever throttle position I choose.Dynamometer can't measure load at any given speed and any gear.
Certainly, Mr./Ms. Desdinova's tweaks would show up on my dyno.Therefore , i.e. other gear roll ons- than top gear -(from any rpm) can't show up in the dyno,from the tweaks.
What is to prevent somone from testing various throttle openings on the dyno?On the street is different because of the different TB degrees you have on different kind of accelerations.
This is incorrect as the map is a grid with throttle positions or manifold air pressure along one axis and rpm along the other. The rate of opening is relatively inconsequential on an injected engine, as the engine is not relying on engine vacuum to supply fuel. There are certainly not 30 or more different maps. On an ECU with both TP and MAP tables, there could be over 30 rows per cylinder to tune. Could this be what you mean?Fast opening or slower openings of the throttle are represented by different kind of maps due to different TB opening degrees even at same gear and same rpm. Now most of them are covered with each other (smal differences) cause my chip map is not so sophisticated to have i.e. 30 or more maps that represent different TB openings.
That sounds reasonable in most cases. However on some engines, depending on the state of tune, best power everywhere will make the bike difficult to ride as the HP may increase by 20 hp over the span of 1000 rpm (as an example).When I started my tunning I said O.K. I'll make different maps but at one I would have to have best power the motor can give,at any given RPM at an given gear, at any throttle opening. Because this is also the usable power , in all conditions and mostly at every day use.
Actually, if you want best power, it is best to stay away from supposed AFR measurements, at least by O2 sensor. If you want best power, power, rather that O2 content, must be the arbiter. In fact, looking at AFR as derived from an O2 sensor can mislead severely.How can one know this? by measuring the AFR some say best power is achieved at 12.2 ,while others to 12.6-12.8(pounds of air to liter fuel).
You will be best off with going with what you notice, regardless of the values returned by an O2 sensor.I can notice, the positive power difference of the bike at these values and I do accordingly.
Agreed on all points.Flashing richer maps won't alone do the trick ,and the spark advance has to be also concidered for some fine tunning as well as the tempratures have to be concidered (that's a hot issue
) for having the optimum map with either colder or hotter engine or wheather.Regards,
Derek
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Note the "crankshaft din" business. The engine was tested on an engine dyno (rather than a chassis dyno) or a dyno that measures the driveline losses, or some silly arbitrary "correction factor" was applied.
Regards,
Derek
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What would help your argument would be to ask for the comparisons for all of the other throttle positions including EGA data.
Regards,
Derek
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I think there is a chance a pre-fab map can be correct, but my experience corroberates that the chances are slim. Considering how many breakpoints there generally are in a map (multiplied times the number of cylinders), and in the case of Guzzi, temp & pressure correction problems, there are many chances for errors. I have to wonder where the 100 people you spoke with took their bikes.David, let's just set the record straight that this is just your opinion. That said, yes every bike should really spend some time on the dyno to assure things are ideal... HOWEVER, from *my* experience, with most maps of exact mods and TPS setting, pre-built maps can be amazingly accurate. I've spoken with well over a hundred people that have taken their bikes to the dyno, and were told that there was no need for a custom map.Your "always wrong" statement above is blatantly incorrect, and I'm not sure what qualifies your "experience" with tuning outside of tinkering and taking your bike to a Tuning Link dyno awhile ago. Don't mean to be harsh, but I cannot/will not allow misguided/incorrect information on this subject.
This will be my last post on this topic.
Regards,
Derek
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Realizing that this post was mostly in fun, I still have to say that faith based tuning is precisely what I am against. Don't you want to know that the engine is running a particular way rather than believing it? While I understand and agree that there are no absolutes, it is possible to proceed based on evidence rather than faith. Gathering the evidence requires the equipment most suitable to the task. Would you go have some tea leaves read in order to determine the state of tune of your engine? To each his own, but I don't see it as likely, nor likely to be accurate (you never know I guess). Likewise, you are not likely to have your local shamanic practitioner perform some ritual to to get your engine to run better (unless the "ritual" involves brake dynos, EGAs and maybe flow meters). People do seem to get nearly as defensive about their faith based choices with regards to tuning as they do about their choice in religions (so far, short of killing each other).I guess it is kinda like choosing a religion.Santa, Mohammad, and Jesus all have something good to offer for believers.
But the important thing is not to over-analyze and just have faith.
Otherwise you'll be like me and spend eternity in limbo.
If you choose Tuning Link or Factory Pro, you'll get better results either way...all you need is faith and $$$$, results are proportionally related.
If I had more $$$$, without question, I would get the Mike Rich porting, hotter cam, Carrillo rods, lighter better pistons, engine balancing, and then head up to MotoLab and give them $2000 to tune almost every point on the map to the nearest HP.
I can only imagine what a sweet ride that would be.
I have little faith and less money, so I am going the DIY route....and I am getting closer to perfection.
Marching forward with Derek's and Todd's advice, and with a little help from the available PCIII maps on the internet, I march forth like a soldier in to war, wearing a crucifix, star of david, ahnk, Om, star and moon of Islam, etc.
Ratchet, I think TuneBoy has your DIY name written all over it.
Regards,
Derek
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Hmm, I'm not sure how you could ever get the map to ping, although the engine might...Weather conditions vary the results, so I want to make sure my map is not pinging.
Two of them with logging might.I plan on getting a WBO2 sensor to optimize it better than my natural senses can.The greatest limitation of my senses is the inability to differentiate right/left cylinder differences.
I think the WBO2 will help with that.
I would love to do it. Does anyone want to let me borrow the equipment? It must be noted that this comparison will not demonstrate the problems related to input voltage, probe temperature, pressure variations or transient response, as in order for the EGA to work, testing must be done steady state. The way to include those problems in a comparison would be to "Autotune" (with PC or TuneBoy), let an ECU (such as Cliffs) tune itself in closed loop mode, or manually tune using a WBO2 sensor and then see by how much I could improve the mapping from there.I'd love to see Derek monitor WBO2 readings parallel with his O2 readings and CO readings, to see if the WBO2 follows more in line with the more useful CO readings.Regards,
Derek
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I'm sorry, but I don't smoke.Perhaps you should re-read post #57 again............... Without the doobie!
I had not read post #57 before my last post. I was referring to post #1, where you said "You will note that there was no huge gain in HP or torque, but it flattened the A/F curve nicely. which should result in notably better milage becasue the curve was WAY rich above even best-power." I read post #57 just now, and I consider whether or not you will achieve the results you are after with this method to be debatable (see the ECU thread if you have not already).
Regards,
Derek
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Right, but what I'm getting at is that 100% throttle runs say very little (if anything) about what to expect in terms of mileage.Not a claim, but one of the goals of the whole exercise."...............which should result in notably better milage .........."
Plus..... you will note that I had mistaken the lean numbers for rich in that first post.
Derek
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Hmm. Then I'm confused about the claim of improved milage in your original post.Yes it does.... The Dyno pull was done indoors on Dec 2, 2004. Street tuning runs are proposed for April, when the snow goes!Regards,
Derek
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Does this mean the part throttle runs/tuning ghave not been done yet?It's December here in Canada, so while the answer is "yes", it isn't going to be any time soon!
Cool. What are you up to?We're busy!!
Regards,
Derek
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I would say there are a few shops where this is likely to be common practice. AF1, Wheelsmith/Factory, Evoluzione and World Class Tuning come to mind. If you have a shop in mind, just ask them if they tune other than 100% throttle. Ask them to see the before and after runs for a bike that had all throttle positions tuned. Ignore the "air fuel ratio" trace and review the differences in the HP and torque curves.I'm in Redwood City, CA 94063.
Regards,
Derek
Can you post the graphs that show the part throttle improvements?The bottom line to the PC III tuning effort was to get something like decent gas milage, by losing the over rich section, and to get rid of the flat spot in the WOT accelleration mode.Regards,
Derek
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For a given intersection of TP and rpm, I can't think of any.If you are at maximized HP, theoretically you cannot be running too lean....but there are probably exceptions to the theory.Regards,
Derek
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It will make it to operating temperature no problem if you use a brake dyno, if it is put through a proper warm up sequence, and the fans are controlled properly (left switched off proportionately more than at higher ambient temps).But if an air-cooled bike, like the Guzzi V11, and a water-cooled bike with the most state of the art ECU and thermostat, are dyno'd at 80ºF and then at 30ºF, I would think the power readings for the water cooled bike MIGHT be accurate to 1% or better, but the air-cooled bike might read 85 corrected HP at 80ºF with an optimal engine temperature for producing power, while at 30ºF the engine may never reach the optimal temperature to reach the same corrected HP, and may only put out 80 corrected HP.
Runs without correction are essentially useless, because they can't accurately be compared. It should also be noted that it's possible for a dyno operator to manipulate the numbers to make the results look better by leaving the correction off.I am not sure, but I think it implies standard HP as measured, without corrections for weather conditions.STD is printed Brian's earlier Dyno Graphs.
Regards,
Derek
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"Ever" seems a bit strong. What if the 2 hp make the difference between passing or being passed on the straight? What if you only have 20 or less HP to begin with (raise that number in proporion to experience)?No one will EVER recognize 2hp...
Can you clarify what you meant is "NOT the strong point of the PCIII" then?No.
I'm not sure we're saying the same thing. If the ECU's temp and pressure compensations are correct, the engine temp is constant, and SAE (or other) correction factors are used, the numbers produced on the dyno should repeat. I agree that it's tough to get them to repeat from location to location, especially from DynoJet to DynoJet or between unlike brands. I have, however found my dyno's readings to be within 1% or better compared to Wheelsmith/Factory's.My only point was that depending on temperature, humidity and altitude there will be different dyno/power results, even with the same bike. Every dyno/location are different, as I'm sure you'd agree. We're saying the same thing.Regards,
Derek
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No, I'm on Rolison Rd. between 2nd and 5th Aves.It's been a long time since I stopped in there, but are you by any chance the shop on El Camino Real south of Woodside Road in RWC?Regards,
Derek
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I would say there are a few shops where this is likely to be common practice. AF1, Wheelsmith/Factory, Evoluzione and World Class Tuning come to mind. If you have a shop in mind, just ask them if they tune other than 100% throttle. Ask them to see the before and after runs for a bike that had all throttle positions tuned. Ignore the "air fuel ratio" trace and review the differences in the HP and torque curves.What you indicated above makes complete sense to me. I reckon it'd be the best "real-world" approach to dyno tuning for my purposes. My question is this - Is it common practice anywhere to do dyno pulls at many "real-world" throttle openings as you indicated, or is this unique to your approach?
I'm in Redwood City, CA 94063.I visited your site. Where is your shop located?Regards,
Derek
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What is "STD"?One dyno I believe is STD and the other SAE
It should make it run hotter, as the correct amount of fuel will be provided to match the denser air.The ECU allows for more fuel when the engine and air are cold. Once you get to around freezing there is some enrichment.But I am not sure that is a good thing. I suspect it will just make the bike run cooler and it will make less power and efficiency.
I don't recommend it, unless it is known to be too rich.So my idea is to map the ECU to run leaner when air is cool, I may be totally wrong. But it seems like a good idea to me.
Best not lean it out with no evidence that it needs it.Just want to keep it running smoothly and don't want to burn any valves.Regards,
Derek
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Certainly, a peak power run would have to, by definition, be at 100% throttle. But to my knowlege, neither the Dynojet dyno nor the PCIII limit you to 100% throttle runs/tuning. Or are you saying that for some reason, the PCIII does not allow for tuning of 100% throttle very well?Every peak power "pull", as shown, is at 100% throttle... which is NOT the strong point of the PCIII.Regards,
Derek
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The dyno's SAE (or other) corrections cannot compensate for the ECU's possibly incorrect temp and pressure trims (nor should they).Disagree. Power measurements are a direct proponent of air (and humidity) supplied to the motor. The dyno has "correction" software, but it is obvious that lower (denser) altitudes and low air temps will yield higher numbers.Regards,
Derek
Dynojet tuning of PC III
in Technical Topics
Posted
"For the rich mixture side, where there is no oxygen, the sensor measures the amount of CO and H2 in the exhaust gas"
The way the rest of the text reads, they are trying to keep the cell at 14.7:1 and the oxygen is either pumped away or provided by reaction and pumped in to make this happen. What convinces me that the oxygen must be gone completely for the thing to react CO and H2 is that I don't think the thing can pump oxygen out and in simultaneously. Maybe not all of the O2 on the rich side is provided by reaction? They also say this:
"We have explained the excess-oxygen case where the air-fuel mixture is lean. How does it operate on the oxygen-depleted side, or rich air/fuel ratio side? For this case, oxygen is ‘pumped’ into the measurement cavity simply by reverse application of current on the pump element. Feedback on the Nernst measurement cell indicates when stoichiometric equilibrium has been achieved. Now, something should be bothering your gut right about now…The pump cell operates on oxygen ion transport, but we are in a situation where there is no oxygen in the air-fuel mixture (i.e. we are rich). If we become much more rich, we still do not have oxygen. Super rich, and still no oxygen. How can there be a feedback situation in this case?"
To me, this quote implies that they expect all O2 to be gone when the thing goes from pumping out to pumping in (i.e. on the rich side of 14.7:1). The word "stoichiometric" (which for gasoline is 14.7:1) also implies that all oxygen (and fuel) is used up. Since this is not possible, it would be of some (limited) interest to know just how many percent O2 they expect to be left over at 14.7:1, if not zero. This then brings up that the sensor could only be accurate for one particular level of efficiency, if at all.
Regards,
Derek