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Discussion in 'GS Boxers' started by Poolside, Nov 18, 2010.
Gotta love these guys! Carry on boys...
<BR><table border="0" cellpadding="5" width="650"><tr><td>When I posted that data acquisition picture, the picture with the stuff on the tank, I didn't want you guys to think that was how complicated it is. That is the development and research setup I use to figure out all of this stuff.
You guys are right though, it isn't pistons and cams. You can go ahead and make those mechanical improvements. But without making changes to how the ECU delivers fuel and spark, the drivability issues will remain, and in many cases they get worse.
At this time there's four products in the works. Following posts are an explanation of the first two products, since they are close to being finished.
I'm sure most of you have a basic understanding of how EFI works. The ECU reads the sensors, air temp and oil temp for example, looks at the motor RPM, checks how far the throttle is open, and injects the right amount of fuel.
This is important:
The air temperature controls the 'open loop fuel mixture'.
The oil temperature controls the 'accelerator pump' feature.
"What do you mean by open loop fuel mixture?"
Here's what I mean. The fuel injection computer reads the air temperature and air pressure, and computes the 'weight' of the air. Then, based on the RPM and how far the throttle is open, it computes how much air is going into the motor. Finally, it squirts the right 'weight' of fuel into the motor to make the right air fuel ratio. For example, the familiar 14.7:1 by weight ratio.
"What do you mean by 'accelerator pump' feature?"
Here's what I mean. I'm pretty sure you understand that Electronic Fuel Injection systems do not have a mechanical accelerator pump like a carburetor. But, EFI does have the 'electronic equivalent' of an accelerator pump.
This bears repeating.
The air temperature controls the open loop fuel mixture.
The oil temperature controls the 'accelerator pump' feature.
Could someone please tell me what are the criteria the R bikes use
to go open, or closed loop? I'm coming from an automotive background,
curious on an air cooled bike what the computer must see to go into
closed loop... and what is the threshold to drop back into open loop, say under
Specifics, like temp above ??? throttle position voltage ???, and so on
Although I haven't experienced any bad running from my Megamoto engine I am aware I need a PowerCommander V or similar if I go ahead and fit a race system.
Stock I really can't fault the fueling on this bike, so I really can't see what your offering can give me that a PCV already can?
<BR><table border="0" cellpadding="5" width="650"><tr><td>In a nutshell if you don't mind, cause JJ and I are going to get into much detail later. Color illustrations too!
When the motor is running at a steady state RPM, and the throttle isn't being moved at all, the ECU is in closed loop.
If the throttle is advanced any amount from that steady state, any tiny amount to make the RPMs rise, the ECU is in open loop. There's a lot of complexity in this 'transitional state', especially with small throttle advancements.
At some point after the throttle angle was changed, the motor 'meets up with the throttle' say, and again maintains a constant RPM. The ECU returns to closed loop.
There's a lot of mythology about what happens during open loop and closed loop modes. Much of it concerns how rich the mixture is in either mode.
You know when you traveling at 50mph on a hot day, and just b-a-r-e-l-y crack the throttle, the motor often immediately pings a few times, or feels like it goes 'soft'? That's part of open loop operation.
The EFI's version of the carburetor's accelerator pump is the majority part of that transition. And that softness cannot be fixed with air temperature adjustment. It can be helped a little that way. Maybe a 30% improvement.
You don't need to fit a PC when adding a pipe. Not really.
And you experience the stock fueling as fine. Good deal. You should know that the majority of the day to day, moment to moment improvements in motor operation comes from the fueling improvements, not the pipe.
So, any accelertion from steady state is in transition and can be helped more by an oil temperature adjustment?
In a single word, yep.
To use more words (and there are even more in the works) there is a complex interaction between all of the influencing factors (thus the algorithm) of which the oil temp is the predominant factor (that we can easily influence) in that one condition.
Let me add that Poolside has a REALLY through understanding of how EFI systems operate. This reaches all the way down into the specific functional and mathematical algorithms that are used for the various portions of the EFI states of operation themselves. Which means that depending upon in which operational state' the engine is running, certain variables become important and thus/can be/are externally modifiable without having to re-write the algorithm itself. This is a decidedly GOOD thing for all of us because it means we only have to fuss with certain knobs to get the desired effects in a particular state of engine operation.
It should also be noted that while we use the term operational state we do so in order to help describe how our modifications plug into certain operational states to affect those specific responses from the engine. These terms and our descriptions of them dont really exist within the EFI nomenclature and are meant to help understand, in a simplified way, what is going on and what we can do to modify the engine's response.
This effort was hinted at years ago in a thread that both of us participated in where I asked for more details concerning the operational parameters. My quest was outlined in post #7 of this thread;
We have come a long way since that thread was started and the desire to come to terms with ALL of that info has been greatly simplified, such that we have come up with work arounds to solve or fix the inherent weaknesses that are apparent in the operation of our engines.
Thus far we have identified 5 states that we can modify to our (as in, us riders) benefit.
And we can specifically target the EFI's normal response to these 5 states and reap the benefits of a much 'healthier' running engine.
These 5 particular states are all 'tweakable' by particular adjustments to the sensor inputs to the EFI or by easily overriding certain programmed logical decisions made by the EFI. In either case we greatly improve the engines response from changes made by the throttle and other normal running conditions.
These 5 states are
1. Steady state operation. (no change to the throttle input to the EFI)
2. Increasing the throttle angle. (as in acceleration)
3. Decreasing the throttle angle. (as in decelerating)
4. Starting the engine.
5. Idling the engine.
By themselves each of these modifications are significant and not only noticeable but welcome improvements.
But when used together the results are wonderful. The engine responds to it's full potential regardless of any and all other mechanical modifications, such as pipes, cams, pistons, intake mods, etc., simply because the programmed limitations inherently built into the EFI have been ameliorated.
And it should be noted that the results of our EFI modifications do in fact interact with each other. And indeed we must design each modification to interact with the other(s), or the results can be as bad or even worse than not adding them in the first place.
In short each of our mods can't just simply work by themselves but they also must work interactively with all the rest of them. And as more modifications are added the more complex/important the interactions become.
In addition to all of this, is the need to keep the kits themselves easy to install, easy enough for anyone capable of performing routine maintenance to handle.
AND we are still researching what other areas of engine improvements are possible.
Here's a couple thing to read while you're waiting for more news.
Interesting stuff here.
<table border="0" cellpadding="5" width="650"><tr><td>Hey there Mike, what's up? I'm a fan of thekneeslider.com site too. Lot's of cool things. There's always a fun custom or three to look at.
That blog entry, and the subsequent responses, are a great example of the classic argument. Old vs. Modern technology. I can sure make a case for either, but the result is a tie. The way I look at it is, an emissions carburetor setup runs as poorly as the first iterations of emissions EFI. Emissions carbs and early emissions EFI feel about the same when you twist the throttle.
When I think about how the throttle response feels on the boxer motor, these are the words that come to mind. Weak, Soft, Hesitant, Dead. I don’t really think Crisp, or Snappy. Nope, do not.
Those of you who lived through the emissions carbureted moto era, you know exactly what I'm talking about. The throttle has this 'dead zone' right at tip in. You think they would have sorted that out with EFI, you know? At least with carburetors, even emissions carburetors, you could lift the main needle, and also adjust the idle and tip-in fuel metering. When you get that done right it put a smile on your face.
That same smile-on-your-face adjustment is available with EFI. Though not with carburetor hardware, with electrical hardware.
On the first page of this thread I made a flippant comment about this being the "poolside plug" but this is obviously much more than just another temp sensor circuit aka "booster plug".
I was about to buy a booster plug but I am going to wait til I see your finished product. Pretty cool stuff you guys are working on here.
<table border="0" cellpadding="5" width="650"><tr><td>It's cool BD, when those products first came out I said some flip things myself about the general product category. When I made those remarks I was thinking about some overstated advertising copy.
Thanks for staying tuned. I don't want to talk you out of buying another product, but let me say this.
The first of these devices I'm designing does alter the air temperature sensor signal. But two things are different about it. First is, it's adjustable. And second, without that adjustability it will not work well with the other products.
Changing the air temperature signal does offer an improvement to some ECU operational states, but it does not reshape the 'accelerator pump' curve. Post 62 has a little more detail on that, and JJ and I have more detailed posts coming.
Messers Poolside & al.
Will this device be vailable shortly or will you taunt us further?
Can you start off buying for instance the AIT sensors and then upgrade?
Knowing Poolside, this is a very finely-crafted marketing scheme, so that when he's whetted our appetites and got us raving mad with lust, just at that moment the thread in the Vendors Forum will appear.
Shouldn't the title of the thread be "fine tuning the GS"? Don't get me wrong, I am all for fine tuning any setup but where's the hot rodding?
To me fine tuning is about making adjustments to the existing stock equipment to dial them into the 'sweet spot'.
Hot rodding is about adding external modifications to fix or improve stock functions with 'better' or more dialed in functions. Which is where we're going with all of this.
For many the small 'problems' built into the EFI are just inconsistencies, but to those who know what and how an engine could or should respond these are the result of marketing and emissions compromises that have altered the EFI to meet those 'requirements'. For those who know how an engine should respond they are a continual source of aggravation and frustration.
And for some the only way to really appreciate these differences, is to experience them in a before and after sorta way. Then the improvements, by comparison, will stand out as clear as day.
It's sorta like if you're gunna play, play. Don't just half assed run around and pretend to play.
Or as Yoda said, do, or do not, there is no try.
That there is marketing GENIUS.
Thanks for the plan of action.