ECU

[Guest Steve_W]

Aaaiiieeee! Too many numbers! Head spinning...

 

/runs to door, breathes 25-degree-F air deeply

 

Thanks, guys. You just had to remind me why I'm a Liberal Arts major.

 

Grumble, grumble...

[emry]

Here, to help some of you out with this topic. This site "http://www.autoshop101.com" has a wealth of info, auto-directed, but none the less use full. Much comes form the Toyota Curriculum. Of particular interest.

Combustion

Combustion II

 

From moto's post it is clear that he is tuning for best power. Great, looks very nice on a inertial dyno. But the rich mixture does not always work best for more sedate driving.

 

Best power is not always the best target.

 

Using closed loop is not a perfect solution, but it is better at achiving good combustion efficiency over the long term under a wider range of running conditions. Will this always make the most power, NO, but neither will tuning for a target CO on a dyno, which is a very poor simulation for actual running conditions. Driving around with your 5 gas straped to your seat could be a very expensive experiement. (Even though I have done it.)

[dlaing]

Thanks for the links Emry.

It also seems pretty clear that Moto is bringing up the point that CO may be a better indicator, not just for power, but for tuning for the A:F that works best for our bike.

According to a chart on the first PDF that you linked to, CO gives a better indication of A:F when the A:F ratio is below 14:1, while O2 gives a better indication of A:F above 15:1, and both O2 and CO give good indications in the 14-15:1 ratio, which is where a car would want to be, but not our bikes.

Of course I am merely making the assumption based on the slopes of the curves in the charts. But, Moto's data seems to corroborate that the CO is the better indicator when one is pursuing the A:F in the 12:1 to 14:1 area that we want to run our bikes at, not just for power, although that does appear to be what he was targeting.

It does seem like a five gas analyzer would give our bikes better running maps.

Of course many people have had great improvements using the tuning link which only analyzes one gas. (or am I wrong?)

[emry]

Of course many people have had great improvements using the tuning link which only analyzes one gas. (or am I wrong?)

 

To my knowledge the tuning link only uses O2 sensor voltage becuase that is the only sensor that has a fast enough response time to be used on a inertial dyno. O2 sensors are chemical in nature and thus respond quickly to changes, CO, CO2, NOx are measured using a IR scanner or laser sampling method on the high end machines. The best response time I have seen for those is

 

In summary I would believe that on the road tuning using O2 is the better than nothing, which is the only other option. On dyno tuning setting a CO target probably will get you better results quickly as CO is a better indicator of a rich condition. Although I would be careful to also keep an eye on the other gases. CO is a result of incomplete combustion, and can be greatly effected by poor combustion design, which our Guzzi are plauged with. I would expect a Guzzi's CO to always be much higher than an Aprilia's at a given A/F ratio.

 

And actually Moto I would be curious to see the other gas data you have from the Aprilia and what type of dyno was used. Good choise in 5 gases, I used to use one and found it to have very consitant accurate results, but be careful they don't like dirty filters.

[JuhaV]

Hi,

 

It seems that we have gone quite chemical in this threat I am just thinking aloud below in order to understand this gas issue a little bit better.

 

In practise the only measurable gas on the road seems to be oxygen, because there are no practical gas sensors for the other important gases. The main problem when measuring CO is that in those infrared cells the gas needs to be in controlled temperature and without too much water vapor. Those will namely interfere with the CO absorption spectra and ruin the measurement accuracy. This means that CO measurement can not be done in situ in the exhaust channel. Therefore, CO measurement is done by sampling, which inherently leads to slower response.

 

If we go back to the combustion chemistry. We put in into cylinder air (nitrogen N + oxygen O) and fuel (hydrocarbons CxHx, i.e. hydrogen H and carbon C in diffent combinations). Out comes different things in different combustion situations.

 

Perfect, stoichiometric combustion would produce only water vapour H2O and carbon dioxide CO2, because the fuel and air are in correct ratio and all fuel will be burnt. Nitrogen goes mainly through without chemical reactions, a small amount forms nitrogen oxide NO, which is harmfull but nowdays removed by the catalyser.

 

Fuel rich combustion produces carbon monoxide CO in addition to CO2, because there is not enough oxygen to fully oxidize (burn) all carbon to CO2. So, CO indicates rich mixture. And what is important here is that CO is a combustion product, which means that it is truly produced in such combustion where there was not enough air reacting with the fuel. In other words, if you see CO in the exhaust it for sure means that some part of the combustion is taking place too rich.

 

Fuel lean combustion produces hydrocarbon emissions, because some part of the mixture is too lean to burn at all and can cause even misfire. Also, in this case there is residue O2 in the exhaust, because there was not enough fuel to use up oxygen.

 

Why O2 is not perfect to indicate the status of the combustion process. My understanding is that it is because O2 is not a combustion product. In other words, if you see O2 in the exhaust you cannot tell for sure that this O2 has been even trying to participate the combustion process. It might be there because of exhaust system air leaks or travelling throught the cylinder without ever "meeting" hydrocarbon molecules" to oxidize.

 

The combustion phenonema inside the cylinder is not homogenous and happens very rapidly, therefore the chemistry may not have time to go all the way through to the equilibrium values ? The inhomogenousity means that the are always leaner and richer spots inside the cylinder, especially in these Guzzi engines Even if we but in fuel and air in perfect ratio, because of the non-ideal mixing the result will not be perfect.

 

Hope this is doing any sense.

 

br, JuhaV

[emry]

Yep.

 

Nitrogen goes mainly through without chemical reactions, a small amount forms nitrogen oxide NO

Normally this is formed when combustion temperature gets to high, either through too much ignition timing, lean mixtures, or poor cooling. (All of which our Guzzi's have at some point it seems.) During our Guzzi's infamous "pinging" during accel, NOx levels rise precipitately.

 

Here is some good reading.

 

An older thread on that touch this subject.

[moto]

From moto's post it is clear that he is tuning for best power. Great, looks very nice on a inertial dyno. But the rich mixture does not always work best for more sedate driving.

 

Best power is not always the best target.

 

Using closed loop is not a perfect solution, but it is better at achiving good combustion efficiency over the long term under a wider range of running conditions. Will this always make the most power, NO, but neither will tuning for a target CO on a dyno, which is a very poor simulation for actual running conditions. Driving around with your 5 gas straped to your seat could be a very expensive experiement. (Even though I have done it.)

41045[/snapback]

I am absolutely tuning for best power, but I don't use an inertial dyno. I'm not sure what made you think I do, since no one (at least that I am aware of) manufactures an inertial dyno with an integrated EGA, as it's very difficult if not impossible to sort out the delays properly. What makes you think the mixture is rich in the data I provided? What criterion is used to make this judgement? As far as I'm concerned, if I'm making best bower at a particular throttle position and rpm combination, the mixture is not rich. Once again, I have to ask the question, why do we tune in the first place if it is not to make power?

 

As originally stated, the data in the last chart I posted is at 100% throttle. Why are we talking about sedate driving at 100% throttle? None of that data has anything to do with those throttle positions which one might consider "sedate". But even at those throttle positions I tune to best power when possible, and I see no logical reason why I should not. Here's the Futura's final rear cylinder data at 12% throttle (which I'm sure we can agree is "sedate"), pulsewidths again tuned to within ±.1 to ±.2 hp of best power:

 

Rpm HP ft/lbs CO O2

1455 7.30 26.41 3.4 0.4

1902 9.80 27.11 4.1 0.5

2355 10.61 23.61 3.9 0.5

2653 13.21 26.11 4.4 0.6

3005 14.81 25.91 4.0 0.4

3304 15.71 25.01 4.2 0.7

3604 16.51 24.11 3.8 0.9

4005 17.51 23.01 3.5 1.6

4405 17.71 21.11 3.1 0.7

4906 19.91 21.31 2.7 1.8

5405 20.01 19.41 2.8 0.5

6002 18.31 16.11 4.0 0.5

6401 20.11 16.51 3.9 0.4

6805 20.21 15.61 3.9 0.8

7104 18.91 14.01 3.8 0.5

7402 18.01 12.81 2.7 0.5

7810 17.71 11.91 2.3 0.4

8310 15.29 9.60 4.4 0.7

8805 11.47 6.86 2.8 0.7

 

If best power is not the best target, then what is and why?

 

What is the argument that closed loop is always better at achieving good combustion efficency based on?

 

True that tuning fuel to CO targets on a dyno will not always produce the best power, but it will produce better power than using O2 (or "A/F ratio") targets, especially before timing and/or stagger issues have been adressed. But why use gas content targets as anything other than a rough guide when one can tune to best power?

 

An EGA will only produce meaningful data during steady state conditions, so you would have had to produce steady state conditions in your car. What is the difference between producing steady state conditions in your car and producing them on a dyno? If anything, many steady state conditions that are no problem to produce on a brake dyno are very difficult to produce while driving around.

[moto]

Could the O2 readings be wrong because you are not holding it the setting for a full 40 seconds?

http://www.andros.com/6800spec.htm

Or am I reading the specs wrong, and that

Also the O2 sensor is accurate + or - 0.1 % which is fine, but we should not be nitpicking between a 0.1 and a 0.3%...but then again, I'll bet that on a given day the accuracy is much greater.

the plus or minus point one probably is against a standard rather than the same machine against itself.

41038[/snapback]

How quickly an EGA can respond depends to a large degree upon the speed whith which one can deliver the sample to the sensor. Andros uses fairly low volume pumps because water vapor has a greater chance to condense and filters stay cleaner longer (there may be reasons having to do with the other fields their analyzers are used in). This is fine for emissions testing, but not for performance tuning. I use a very high volume pump (comparatively), which speeds the sample delivery rate considerably, use a sample cooler to get the moisture to condense before it gets to the bench, and change the filters often. It's also important to note that the

[moto]

It also seems pretty clear that Moto is bringing up the point that CO may be a better indicator, not just for power, but for tuning for the A:F that works best for our bike.

According to a chart on the first PDF that you linked to, CO gives a better indication of A:F when the A:F ratio is below 14:1, while O2 gives a better indication of A:F above 15:1, and both O2 and CO give good indications in the 14-15:1 ratio, which is where a car would want to be, but not our bikes.

Of course I am merely making the assumption based on the slopes of the curves in the charts. But, Moto's data seems to corroborate that the CO is the better indicator when one is pursuing the A:F in the 12:1 to 14:1 area that we want to run our bikes at, not just for power, although that does appear to be what he was targeting.

It does seem like a five gas analyzer would give our bikes better running maps.

41056[/snapback]

Amen, brother.

Of course many people have had great improvements using the tuning link which only analyzes one gas. (or am I wrong?)

I think that depends on how one defines "great improvements". I think in many cases where an engine has been modified, a tuning link generated map has a chance of being somewhat better than retaining the stock map.

[moto]

To my knowledge the tuning link only uses O2 sensor voltage becuase that is the only sensor that has a fast enough response time to be used on a inertial dyno. O2 sensors are chemical in nature and thus respond quickly to changes, CO, CO2, NOx are measured using a IR scanner or laser sampling method on the high end machines. The best response time I have seen for those is

41077[/snapback]

My EGA responds to CO in ~2 seconds. However this relatively unimportant, because the delay is just set appropriately in the software and the particular rpm step is held until the traces level off.

 

In summary I would believe that on the road tuning using O2 is the better than nothing, which is the only other option. On dyno tuning setting a CO target probably will get you better results quickly as CO is a better indicator of a rich condition. Although I would be careful to also keep an eye on the other gases.

Agreed.

CO is a result of incomplete combustion, and can be greatly effected by poor combustion design, which our Guzzi are plauged with. I would expect a Guzzi's CO to always be much higher than an Aprilia's at a given A/F ratio.

I might expect that as well, except that some engines that you would not expect it of run best with seemingly high COs and that I find the correlation to "A/F ratio" to be irrelevant.

And actually Moto I would be curious to see the other gas data you have from the Aprilia and what type of dyno was used.

Futura data including HC and CO2 for 100% throttle with pulsewidths tuned to within ±.1 to ±.2 hp of best power:

Rpm hp ft/lbs CO HC CO2 O2

1904 15.97 43.91 4.2 668 11.3 0.5

2353 18.76 41.82 4.2 156 11.4 0.3

2655 24.75 48.90 4.2 182 11.5 0.3

3005 31.54 55.09 2.6 427 12.0 0.7

3306 36.13 57.39 3.3 647 11.4 0.7

3606 39.62 57.68 3.6 618 11.3 0.7

4004 44.01 57.68 3.7 596 11.3 0.8

4407 47.01 55.99 4.0 743 10.9 0.8

4906 55.59 59.48 2.7 459 11.7 1.0

5408 63.17 61.28 4.1 599 11.0 0.8

6007 67.56 59.08 4.7 174 11.0 0.2

6406 75.25 61.68 4.2 189 11.5 0.2

6810 85.08 65.66 3.8 596 11.1 0.4

7108 91.18 67.36 4.1 592 11.0 0.3

7408 95.49 67.66 5.1 599 10.6 0.2

7808 98.69 66.36 4.4 469 11.1 0.1

8309 103.29 65.26 3.2 428 11.7 0.2

8809 105.39 62.86 4.3 435 11.0 0.1

9309 107.60 60.70 3.4 306 11.9 0.3

9807 106.40 56.93 4.3 405 11.4 0.4

 

I use a Factory Pro EC997a.

[emry]

but I don't use an inertial dyno

I should have know better, sorry.

 

What makes you think the mixture is rich in the data I provided? What criterion is used to make this judgement? As far as I'm concerned, if I'm making best bower at a particular throttle position and rpm combination, the mixture is not rich.

High CO is very common for a rich mixture. Rich is a common term when more fuel is present than the available O2 required to burn it. The avegae of your total run of HC is 464 ppm. Quite high. What is the current limit for states that mandate emissions testing? Anyone from CA or AZ know? Have these states started to implement the IM240 yet? When I lived in AZ they were starting it but wouldn't let me use the roller, insurance.

 

As originally stated, the data in the last chart I posted is at 100% throttle. Why are we talking about sedate driving at 100% throttle?

The only motorcycle I have ever considered sedate at 100% throttle was a JR50 with the restrictors still in it. We are talking about sedate driving because all of us ride under sedate conditions on the street. I have never met anyone that rides at 100% for very long period of time. Even professional racers only average around WOT 20% of the time at most tracks. Drag racing being the obvious exception. Using a O2 in closed loop can tune for these sedate conditions, where a rich mixture is not desirable, efficiency is. I would think that a Futura owner would like to get better mileage while cruising on the interstate.

 

What is the argument that closed loop is always better at achieving good combustion efficency based on?

It is a reactive engine control, which can tailor a map for current running conditions. Something which no dyno can reproduce. Although I should change "always" to normally.

 

An EGA will only produce meaningful data during steady state conditions, so you would have had to produce steady state conditions in your car. What is the difference between producing steady state conditions in your car and producing them on a dyno? If anything, many steady state conditions that are no problem to produce on a brake dyno are very difficult to produce while driving around.

Exactly. Using O2 sensors do not require steady state conditions.

 

I have not had a chance to work with one of the newer Factory dyno's. What is the max brake rating (tq) and isn't tire slip a problem?

[moto]

High CO is very common for a rich mixture. Rich is a common term when more fuel is present than the available O2 required to burn it.

41115[/snapback]

Right, but by what criterion is the CO on the charts high? As far as I am concerned if I am producing the best power I can at that CO, then it is not high. Most motorcycles produce somewhere in the 3% to 5% range when tuned for power.

The avegae of your total run of HC is 464 ppm. Quite high.

High by what standard? According to the thousands of runs in my database for every type of motorcycle you can imagine in various states of tune 464ppm is on the low to average end except for when a cat is used.

The only motorcycle I have ever considered sedate at 100% throttle was a JR50 with the restrictors still in it. We are talking about sedate driving because all of us ride under sedate conditions on the street. I have never met anyone that rides at 100% for very long period of time. Even professional racers only average around WOT 20% of the time at most tracks. Drag racing being the obvious exception.

Right, that's why I'm wondering why you would talk about the CO shown in a chart for 100% throttle indicating rich mixtures during sedate driving. Also, see the CO for the 12% throttle run. The CO is comparable. I agree with you about most riding happening in the 20% and below throttle range. That's why the Futura's ECU was mapped on the front and rear cylinders individually to within ±.1 to ±.2 hp of best power at 100, 92, 82, 73, 62, 49, 39, 29, 22, 16, 10, 6, 4, 2, and 1% throttle (all throttle positions the ECU interpolates from) at the rpm steps shown in the charts (to where the engine would rev out at the smaller throttle openings). I'm more than happy to post the final runs (and the prior runs) for whatever throttle position anyone is interested in. I do think that at the larger throttle openings are where people have their fun, and that it's anticlimactic for the rider if the engine does not work well there. Plus, you've got to tune 100% throttle for bragging rights, no?

Using a O2 in closed loop can tune for these sedate conditions, where a rich mixture is not desirable, efficiency is. I would think that a Futura owner would like to get better mileage while cruising on the interstate.

Again, by what criterion is the mixture you see on the charts rich? And again, what are we tuning for? While it may be possible to improve mileage from best power by tuning specifically for that, in my opinion the increase in mileage will be small enough to make it a waste of time. I think most people ride a motorcycle primarily to have fun, not to achieve a certain fuel economy.

It is a reactive engine control, which can tailor a map for current running conditions.

An open loop ECU is certainly a reactive engine control. Modern open loop motorcyle ECUs monitor rpm, throttle position, engine temp, ambient temp, airbox pressure and relative humidity at least. With a proper map to make adjustments from, that's more accurate than using an O2 sensor. One thing that people forget is that O2 sensors were not introduced to help performance. They were introduced to assure the proper amount of oxygen in the exhaust gasses to keep a catalytic converter functioning optimally. Also, if stagger issues and timing have not been adressed in the base map, the ECU will meter the wrong amount of fuel in response to O2 sensor inputs.

Something which no dyno can reproduce.

I'm not sure I follow. Can you clarify?

Using O2 sensors do not require steady state conditions.

In my opinion the lack of correlation between the proper amount of fuel and O2 sensor output makes this fairly irrelevant.

I have not had a chance to work with one of the newer Factory dyno's. What is the max brake rating (tq) and isn't tire slip a problem?

The max brake rating is sort of a soft limit. The problem is heat. The cooler the brake, the more HP it can contain. What ends up happening is that at really high HP, the brake can't get rid of the heat quickly enough and then it will gradually let go. I think mine is probably good for 200 and some without additional cooling. How much more it could contain with extra cooling depends on how much was provided. Factory has models available for various applications and with various HP ratings. I'm sure that if they didn't have exactly what you needed, they would build it for you. For example, BRG's model MD-750 dyno is not listed on the Factory website, but will contain 1000HP. Tire slip has not been a problem for me, as the drive roller is slotted and the geometry of the setup causes the tire to "dig in" proportianately to how much HP is being produced.

[emry]

Right, but by what criterion is the CO on the charts high? As far as I am concerned if I am producing the best power I can at that CO, then it is not high. Most motorcycles produce somewhere in the 3% to 5% range when tuned for power.

Agreed, but should we be tuning for best power or best economy at lower throttle settings.

12% TPS

3005 14.81 25.91 4.0 0.4

3304 15.71 25.01 4.2 0.7

3604 16.51 24.11 3.8 0.9

4005 17.51 23.01 3.5 1.6

4405 17.71 21.11 3.1 0.7

4906 19.91 21.31 2.7 1.8

2000 rpm range with 5hp difference. Typical driving. You only need enough force to overcome wind resistance, tire friction, and internal friction. Are we really concerned about power here? Will the owner appricate 1 more HP here or 1 more mpg.

High by what standard? According to the thousands of runs in my database for every type of motorcycle you can imagine in various states of tune 464ppm is on the low to average end except for when a cat is used.

Perhaps I have been spoiled by the automotive world.

Plus, you've got to tune 100% throttle for bragging rights, no?

Spoken like a true dyno operator. You are behind a rock. No one would pay you to tune their motorcycle to be more effecient, and still offer good performance.We as consumers have been brain washed into more power more power more power. Look at the crap they sell "up to 10 more Horsepower, only $19.95!!!" People only want to see a before and a better after dyno run. It's that HP number that matters!!!!!

An open loop ECU is certainly a reactive engine control. Modern open loop motorcyle ECUs monitor rpm throttle position, engine temp, ambient temp, airbox pressure and relative humdity at least.

To my knowledge most are a "Throttle - Speed" variety. Injector duration is found by taking TPS and RPM and returning a value. This is then modified for altitude, engine temp, and intake air temp. Some do use a MAP sensor along with the TPS and RPM for the inital value. This normally works fine and so does dyno tuning. But what take into account the dirty air my engine breathes when plugging along in rush hour traffic, or the bad gas I filled up with, or the dirty air fliter I should have replaced 3 months ago, or the oil that is slipping past my worn valve guides. It is reactive to its inputs, not to how well the engine is actually running.

relative humdity

I haven't seen this one yet.

 

I'll have to finish later, bedtime.

[Cliff]

Well those gas charts certainly explain why the common narrow band gas sensor will not work well with A/F below 14/1. This limitation though should not come as a surprise

 

To dismiss all o2 gas sensors as not workable in the richer range though is to ignore the fact that wide band sensors like the Bosch 0258 104 002, that I use, and the newer 5 wire sensors do exist and work very well in that area. They are the basis of many commercial analysers including RacerX's US$2000 sensor.

 

It may also be true that a single A/F target will not give maximum power across the board. However just as you could tweak each map point to with 1HP by adjusting the mixture, what is to stop one similarly tweaking each points A/F ratio to do likewise. No I don't have that capability today. I could have it tomorrow. One thing I would be sure of though. Which system would still be within 1HP six months down the track.

 

WRT to what do we tune for.

Would I be happy with a 2% drop in power for 5% better economy. You bet.

Would I be happy with a 5% drop in power for 20% better economy. You bet.

Do I care that I get 95HP rather than a 100. No

Do I care that the throttle is responsive and there are no misses at. Yes

I'm considering dual plugging in the future but not because of the HP increase.

 

The good thing is I can have all of those features above, including the 100HP if I want.

[dlaing]

$2000 for a tuning link's O2 sensor?!!!

How much is the Bosch sensor that you use?

Could you bundle it with an accurate* LED meter that would tell me how lean my bike is running and sell it to me for under US $200? (*accurate from 12-15:1 ratio at 0.5 increments. So, it would measure 15 or maybe 7 LEDs or 3LEDs and an adustable target range with 0.5 accuracy)

Does the Bosch thread in to our pipes without modification?