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Old 11-19-2012, 04:40 AM   #241
roger 04 rt
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Quote:
Originally Posted by def View Post
I have no experience with the temperature sensors on our BMWs but, I would suspect they are NTC thermistors which are relatively accurate temperature sensors. However, measuring the resistance change with temperature is difficult because of the self heat phenomena that takes place with a typical VOM. Thermistors have accuracies to 1 C., some even to 0.1 C.

Using the Steinhart-Hart equation, temperature is calculated using the change in resistance reported by the thermistor.
Your understanding of this is correct. Going a bit further:

In simple terms, the IAT changes resistance as temperature changes, the Motronic then measures the IAT sensor's resistance, goes to a table that tells it (based on the resistance it measured) the temperature, and then how much more or less fuel than a "standard day" (20 degrees C, I believe) is needed. It adds or subtracts roughly 6% more fuel for every 20C it is different from the standard day, although it does it with more precision that 20C blocks.

Here is part of the table that I've measured using the GS-911:
IAT Resistance, Motronic Temperature Reported
700 ohms, 50C
1100 ohms, 40C
1600 ohms, 30C
2.5K ohms, 20C
3.5K ohms, 10C
5K ohms, 0C
8.5K ohms, -10C
11K ohms, -20C
25K ohms, -30C
Here is a longer article: IAT Sensors.

If you look at the Open Loop steps in the Motronic Closed Loop Block Diagram, you can see that an Open Loop (red highlighting) correction for temperature is just one of the adjustments the Motronic makes to the fueling number (e.g. barometric pressure, battery voltage, etc.). When the Motronic is Closed Loop (green highlighting) the IAT sensor, and most other sensors, aren't used to calculate the fuel pulse.

Also in simple terms, the barometric pressure sensor (on the Motronic) and the IAT sensor (in the air intake) let the Motronic calculate with more precision, how much oxygen is in the air going into the cylinder.

If you want a permanent change in AFR, you either have to disconnect the O2 sensor so it doesn't get a vote (which causes other issues) or you have to provide the Motronic MA 2.4 with a richer O2 Sensor. The reason is that the O2 sensor is the ultimate controller of mixture for both Closed Loop (directly using the O2 sensor), and for Open Loop (as it creates correction factors, called Adaption Values).
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Old 11-19-2012, 05:36 AM   #242
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FF and MrC, FYI, here are a couple notes I add to the PC implementation:

5) Because the Powercommander gets its +12V from the injectors/fuel pump and since the fuel pump goes off after a couple seconds, Dynojet recommends hitting the starter button before the fuel pump cycles off.
6) The Powercommander may not take injector dead-time into account (seeking clarification from Dynojet. If that is the case, I will update the sample fueling tables. For example, since there is 1 mS of dead-time in a 2mS injector pulse only a +3% is needed to get 6% enrichment.

In my case since I've boosted fuel pressure to shift the tables, the dead-time is automatically taken into account.
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Old 11-19-2012, 07:01 AM   #243
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Thanks for the extra info Roger. I will not be changing any PCIII tables until I get the AFR gauge. Mr. C it is one of those eBay vendor things, they don't ship as quickly around holidays for some reason. I got it for 68 shipped, though.

What I wanted to do in the mean time was got to 13.5 AFR or lower, then advance the timing slightly and see what happens. Premium fuel only. For science.

Long story short my view of this whole exercise is the following. The Motronic 2.4 is not exactly what one would consider a state of the art EFI system. In fact it is pretty primitive N-alpha though perhaps well-executed. One step up from mechanical injection. BMW and all motorcycle engine manufacturers were faced with increasingly tight emissions regs coming, and this is what they came up with as a band aid. If my experience on german cars is any indication, what was done was significantly detune the engine to meet regs, and force lean AFR's, at great cost to performance. And then make the engine bigger to try to compensate. Amazing how poorly some basically great motors from that era ran when forced to meet emissions with a bad compromise solution. And how well they run when you rip all that shit off.

This is especially hard with air cooled engines, and what led Porsche for example to abandon them entirely late 90's. The point here for the R1150 motor is, it has never run as well as the smaller unrestriced boxer twin with carbs, so extensive was the strangulation with cats and emissions controls and primitive EFI. In BMW's case the boxer twin is somewhat iconic (like Harley and their V-twin) and they could not just abandon it like a lot of Japanese bike manuf did with their air cooled motors.

The fact that the very simple mod of tricking the motor one way or another into running a bit rich equally across all conditions improves things so much (without re-tuning base VE map) to me is a clue as to how badly restricted it was, and how poor the compromises were. In any case I suspect based on many years of doing this with cars with these early attempts at emissions compromises, you remove flow restrictions, get a good fuel map going, advance timing a bit and you completely transform the character of the engine, with better drivability, fuel economy, and a LOT more power.

That is the hypothesis at least.
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Old 11-19-2012, 07:53 AM   #244
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Originally Posted by fred flintstone View Post
...

The fact that the very simple mod of tricking the motor one way or another into running a bit rich equally across all conditions improves things so much (without re-tuning base VE map) to me is a clue as to how badly restricted it was, and how poor the compromises were. In any case I suspect based on many years of doing this with cars with these early attempts at emissions compromises, you remove flow restrictions, get a good fuel map going, advance timing a bit and you completely transform the character of the engine, with better drivability, fuel economy, and a LOT more power.

...
Although I prefer to think of the Wideband O2 as a reprogramming of the Lambda setting (rather than tricking anything), I agree with your conclusion ... the 1150 Oilhead runs a lot better with only a little additional fuel. I'm running 6% more but as little as 4% more makes a much bigger difference than one would expect--8% more fuel even improves things further. And you get a much different result with a Wideband O2 than you get merely changing the fuel pressure or air temperature.

My experience says the fuel mileage suffers a mile per gallon or so but it is hard to tell because it's easy now to run one gear higher than before.

I think most 1150 owners would get a good band-for-the-buck with only a WB O2.


I've run a few different Coding Plug trials and have put that aside. I just don't see a meaningful difference and the timing seems odd. It appears to me that the Base VE map and spark timing are pretty good as delivered so I will be running the stock Coding Plug. This has been very interesting.
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Old 11-19-2012, 08:24 AM   #245
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Originally Posted by roger 04 rt View Post
Although I prefer to think of the Wideband O2 as a reprogramming of the Lambda setting (rather than tricking anything), I agree with your conclusion ... the 1150 Oilhead runs a lot better with only a little additional fuel. I'm running 6% more but as little as 4% more makes a much bigger difference than one would expect--8% more fuel even improves things further. And you get a much different result with a Wideband O2 than you get merely changing the fuel pressure or air temperature.

My experience says the fuel mileage suffers a mile per gallon or so but it is hard to tell because it's easy now to run one gear higher than before.

I think most 1150 owners would get a good band-for-the-buck with only a WB O2.
Definitely agree with this conclusion, and at the price point of the LC1 (under $200) I think that is the best solution of the 1 degree of freedom type. Esp since you can set it higher or lower and have data acq. The PCIII wideband is a different animal with the programmable trim tables, but the jury is still out as to whether that is useful. I'd like to hear from folks who used the LC1 with cat delete, lot of stuff going on here we don't understand fully yet WRT base maps on various r1150 permutations.

I was fortunate to pick up a PCIII for cheap, I don't think I'd lay out $500 for it now that I know the LC1 is available. However at $150 it was a screaming deal.

Anyway thanks to Mr C for the original recommendation and to Roger for all the subsequent insights. Hope to post up some experimental results soon if weather & times permits.

One thing I did want to make clear, a lot of particular issues with my bike and lean/pinging conditions could be altitude related. Esp on the air cooled motor where you lose cooling capacity because of thinner air, above 8k ft and hot temps, slow riding behind tourists on narrow mountain roads put that poor old motronic into a corner of its adaptation tables the motor does not like very much.
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Old 11-19-2012, 11:33 AM   #246
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FF and MrC, FYI, here are a couple notes I add to the PC implementation:

5) Because the Powercommander gets its +12V from the injectors/fuel pump and since the fuel pump goes off after a couple seconds, Dynojet recommends hitting the starter button before the fuel pump cycles off.
6) The Powercommander DOES take injector dead-time into account.

In my case since I've boosted fuel pressure to shift the tables, the dead-time is automatically taken into account.
I just heard back from Dynojet. They do take dead-time into account within the PC III USB, they said.
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Old 11-19-2012, 01:41 PM   #247
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Roger, I have a question, actually several;

My 2001 GS runs well for its age and consistently delivers 42+ MPG (mostly running errands, rarely sees the E gear ratio). Currently it runs smoothly, starts reliably and has all its life. The engine is stock with OE exhaust, CAT and code plug. I perform all the tuning, maintenance and repair myself (stock settings for all adjustments).

What will I gain by modifying the fueling? Improved MPG? Increased BHP? Smoother running?

What fueling modification should I make to achieve the improvement?

How much will it cost?

Should I monkey with ignition timing, valve lash settings, Lennie's sprockets?

Thanks for your thoughts and comments.
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Old 11-19-2012, 02:06 PM   #248
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Reading and learning.
In simple words, understood the lambda pertinence after this article.

http://www.enginebasics.com/EFI%20Tu...%20Basics.html

Thanks Roger
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Old 11-19-2012, 03:19 PM   #249
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Roger, I see reference to a pressure sensor in the Motronic.

When did the Motronic get a barometric sensor? I thought that Lambda was the only way O2 was calculated???

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Old 11-19-2012, 08:34 PM   #250
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Hi Def, I'll do my best to answer these questions. It sounds like your GS is in similar condition to my RT. I began the project when I realized my motorcycle ran a bit stronger during warmup than after Closed Loop. My experience with mixture management in my Bonanza left me wishing for a similar control for the motorcycle.

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Roger, I have a question, actually several;

My 2001 GS runs well for its age and consistently delivers 42+ MPG (mostly running errands, rarely sees the E gear ratio). Currently it runs smoothly, starts reliably and has all its life. The engine is stock with OE exhaust, CAT and code plug. I perform all the tuning, maintenance and repair myself (stock settings for all adjustments).
Your bike seems like a good candidate for a richer mixture.

Quote:
Originally Posted by def View Post
What will I gain by modifying the fueling? Improved MPG? Increased BHP? Smoother running?
Same MPG, I get 42/43 around town. Although I've gone 6% richer on the mixture, between 14.7 and 13.8 you get about 3% more power for 6% more fuel. And because you're shifting up at lower RPMs you are often running at a more efficient BSFC. Net net I may suffer one mpg.

More usable torque between 2000 and 3500 RPM. I am in 5th gear between 35/40 and in 6th gear by 55. It's hard to explain but easy to experience the sense that when you roll on the throttle, the bike wants to accelerate. It feels more like a big twin and, pardon me, less like a two stroke. 4th gear is responsive by 2100 rpm, 5th gear by 2200 rpm and 6th gear by 2700 rpm. The engine is happier at a richer mixture, no feeling of holding back.

Top power is the same. The WOT afr was already at or near Best Power Mixture.

Probably less vibration due to richer mixture more equally consuming the available O2 in the cylinder. Once the O2 is gone fuel imbalance doesn't effect power balance. And this will sound strange but a huskier exhaust note--I know, who cares?

Quote:
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What fueling modification should I make to achieve the improvement?
The PCIII USB is easy to implement and costs about $400. The Innovate LC-1 needs some wiring before installation. I've got a thread on it, here, $160 at amazon. I've tried to list the pluses and minuses near the end of my Wideband o2 thread. If you go with the LC-1 you get faster adaptation with something to shift the fuel table like a 3.5 Bar regulator or a BoosterPlug. I went with the pressure regulator. You can find 35 bar used for $30 or $40, no plumbing.

Quote:
Originally Posted by def View Post
How much will it cost?
Under $200.

Quote:
Originally Posted by def View Post
Should I monkey with ignition timing, valve lash settings, Lennie's sprockets?
Other than changing the Wideband and maybe boosting the pressure, everything else remains stock. Stock Coding Plug.

Quote:
Originally Posted by def View Post
RThanks for your thoughts and comments.
Quote:
Originally Posted by def View Post
Roger, I see reference to a pressure sensor in the Motronic.

When did the Motronic get a barometric sensor? I thought that Lambda was the only way O2 was calculated???

The MA 2.4 (and 2.2 I believe) have always had an onboard Bari pressure sensor for calculating one of the terms in the OPEN LOOP fueling path.

For Closed Loop fueling, most sensors aren't used once it has converged. The O2 sensor is paramount in closed loop but a quickly moving TPS throws it back to open loop. I've posted some block diagrams if you want to look at the various fueling paths.

When you shift lambda richer, warmup and wot also get richer by the same amount. 6% richer doesn't seem to be a problem but I wanted to mention it. I settled on lambda = 0.94 (13.8:1) but 0.96 and 0.92 also work pretty well. I may try 0.92 again because I think there's still a bit of cruise power I'm leaving on the table.
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Old 11-20-2012, 04:29 AM   #251
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Originally Posted by def View Post
Roger, I have a question, actually several;

My 2001 GS runs well for its age and consistently delivers 42+ MPG (mostly running errands, rarely sees the E gear ratio). Currently it runs smoothly, starts reliably and has all its life. The engine is stock with OE exhaust, CAT and code plug. I perform all the tuning, maintenance and repair myself (stock settings for all adjustments).

What will I gain by modifying the fueling? Improved MPG? Increased BHP? Smoother running?

...


Thanks for your thoughts and comments.
Def, A guy named Steven Mullen runs a Harley Modifying company called Nightrider.com. Steven is a very straightforward guy and holds a patent on a series of IED products that he's designed that shift the effective switching points of stock narrowband O2 sensors connected to Delphi ECUs. He's written a ton of stuff and has helped me to understand a few points in my process. Here is a comparison chart he did for Harleys. The only thing we don't agree on is MPG. He basically says any added fuel is wasted and hits MPG. My tests say that the combination of slight extra HP and the ability to shift to higher gears sooner almost offsets all the extra fuel

Here is a comparison chart for various O2 shifts and then an LC-1 install video.

IED Nightrider Product Line

Add an LC-1 Video

Here are some lambda shift advantages he lists:
Lowest Exhaust Temp
Lowest Engine Temp
Improved Throttle response
Decreased engine ping
Fully programmable
WBO2 AFR gauge available
Advanced tuning tools
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Old 11-20-2012, 04:40 AM   #252
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Just opened this thread and really don't want to read 17 pages of posts. What caught my eye was another IAT discussion. Ran a Booster Plug with limited to no effect. There are several articles on IAT devices and my summary of them is that the best you get is a small shift in your map. It works for some people, it doesn't work for others and IMO fools a lot of folks into thinking it did something. The OP was worried about ping, IMO ping usually boils down to one of two things: bad/wrong gas or the way the rider applies the throttle.
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Old 11-20-2012, 04:53 AM   #253
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FF and Mr.C,

There was an issue with the way that I was taking data on the Coding Plugs so I am going to rerun the tests over the next few days. In short, I had left my Battery Tender connected since I was on the stand (none of my prior tests were influenced this way) and it held the Battery +12V to 12 volts for the first two minutes of the test. On the 30-87a plug test, two minutes was enough time to get to closed loop so I couldn't see it on the printouts.

However, yesterday I ran a 30-87 test, at the 3:20 point you can see AFR step down (into what I had expected it would be). Some searching showed that the battery voltage jumped from 12v to 14v (normal). When it did the mixture stepped to a richer level.

What was happening?

1) The Motronic measured the low battery voltage and responded by increasing the length of the injector pulse and lengthening the dwell interval. Injection time during the low voltage period was about 0.2 mS longer than usual but the Open Loop calculation that added time doesn't add quite enough. The dwell was increased from 14 degrees to 24 degrees to give the coil enough energy.
2) At the lower voltage, the injectors need a lot more time to open, maybe another 0.3/0.4 milliseconds. When this event happened on the 30-87a test the bike had already warmed to Closed Loop and the Closed Loop routine added enough fuel that until I parsed the data I couldn't even tell it had happened. The fuel was roughly 20% higher at the low battery voltage but AFR was rock steady. Dwell was up to 24 degrees but it didn't seem to affect the AFR.

Moral of the story; No more tests with the Tender connected! And more importantly, the Motronic has a lot of functions to protect the bike that we're still unaware of: Low Voltage leads to longer Dwell. But there's another message. Closed Loop is a powerful part of the Motronic's capability with many unseen benefits.

Here's the AFR chart of the 30-87 Plug run. The run began with a dead cold engine from overnight.
-40 seconds to 1 minute is the Start-Up Enrichment Phase
-1 minute to 3:20 is the Warm Up Enrichment period with the battery at 12V. Notice that at 1 minute the engine looks leaner than at 3:20. This is because until the engine warms a bit a lot of the fuel condenses on the wall and doesn't get burned. The data up till 3:20 was all shifted higher by the battery voltage at 12V affecting the reduced amount of fuel put out by the injectors at low voltage.
-Then note the AFR step down at 3:20. That is where the Battery Tender let go and the voltage jumped to 14V. From their on the mixture was then leaned out by the motronic as the oil temperature got warmer. From 3:20 onward (after the battery voltage goes to 14V) the data is all as I would expect.
-At 5:10 you can see the Motronic lock on to Closed Loop at 13.8:1.

I will start reruning the Coding Plug start-up measurements.
RB

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Old 11-20-2012, 06:14 AM   #254
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Originally Posted by legasea View Post
Reading and learning.
In simple words, understood the lambda pertinence after this article.

http://www.enginebasics.com/EFI%20Tu...%20Basics.html

Thanks Roger
It's a good teas, thanks. The interesting shaded region called Best Power on the graph is what this is all about. Using the WB O2 to shift the cruise running point from a lean 14.7 toward Best Power, not all the way to Best Power, just a shift in that direction.
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Old 11-20-2012, 06:26 AM   #255
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Just opened this thread and really don't want to read 17 pages of posts. What caught my eye was another IAT discussion. Ran a Booster Plug with limited to no effect. There are several articles on IAT devices and my summary of them is that the best you get is a small shift in your map. It works for some people, it doesn't work for others and IMO fools a lot of folks into thinking it did something. The OP was worried about ping, IMO ping usually boils down to one of two things: bad/wrong gas or the way the rider applies the throttle.
Because the O2 sensor gets two votes: 1) It sets Closed Loop fueling and 2) it creates adaptations for Open Loop, it is nearly impossible to get a consistent amount of added fuel without an O2 shift--unless you permanently disable Closed Loop.

I have found my BoosterPlug to be useful in connection with a lambda shift. The BoosterPlug can reduce the amount of adaptation work that the Wodeband O2 and Motronic have to do. An example of that say at a certain rpm and TPS the Motronic outputs a 3 mS pulse and expects that pulse will yield an afr of 14.7. In a lambda shift system to 13.8 it would take a 6% longer pulse to hit 13.8 (6% times the 3 mS pulse minus its 1mS dead time means add 0.12 mS), a pulse of 3.12 mS.

You can either get to 3.12 mS by letting the Motronic figure it out in closed loop, or shift the air temp so that instead of start at 3mS and adjusting, it started at 3.12 mS. Apologies if this sounds like double talk.

The other thing you can do to shift the fuel tables is increase fuel pressure so that a 3 mS pulse at the higher pressure produces the same amount of fuel as a 3.12 mS pulse at standard pressure. Is your head spinning?
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