| Author | Message | ||
     Swordsman |
While I was out and about on my Ss yesterday (weather finally warmed and dried enough to go for a ride, and the bike ran pretty darn well!), I got to thinking about tuning. I've lost count of the number of threads I've perused where the author (and other posters) was attempting to figure out the mysterious ways in which Buell has the ECM configured. It seems that no one is 100% certain exactly how the O2 sensor and AFV work together with all the other little tidbits. There's a general idea, but no real consensus as to what kicks in when and how much. I know a few of you out there have put in major time and effort to figure it out, and have garnered enough understanding to get specific things accomplished. But from what I can gather, all the "answers" have yet to be revealed, and even the gurus are still learning. So, with that in mind, here's my question: why can't Buell just tell us exactly how these things work, and eliminate all of our guesswork? Maybe my business sense is out of whack, but I don't see any harm that could come from it. Given its quirks, I highly doubt some other company is going to snatch up the info and duplicate it. Is there really a reason for it to remain such a mystery? ~SM | ||
| Id073897 |
I've lost count of the number of threads I've perused where the author (and other posters) was attempting to figure out the mysterious ways in which Buell has the ECM configured. I don't see anything mysterious there. Compared to some state of the art automotive systems the ECM works quite simple and straitforward. Wikipedia, google and a well-assorted library should be your friends. Without knowing the basics of EFI and control systems, you will never be able to dive into ECM configuration - even if Buell would tell you what you want to know. | ||
| Pkforbes87 |
Dynamic Digital Fuel Injection The Basics of Buell's Electronic Fuel Injection System Buell's Dynamic Digital Fuel Injection (DDFI) enhances engine performance using advanced computer technology. A microprocessor inside the Electronic Control Module (ECM) makes hundreds of changes per second. Each adjustment allows precise fuel and ignition mapping to the Buell powerplant for the current environmental conditions. The speed that the system can change the fuel & spark delivery to the Buell powerplant is incredible. The Buell DDFI can make hundreds of changes per second. Benefits of this system include an improvement in midrange power, easy cold starts and onboard diagnostic capability. This system also compensates for altitude changes. The DDFI system uses several sensors to provide feedback about external and internal operating conditions to the electronic "brain" of the system, or ECM. These conditions include: Rider input (throttle position) Engine load External environmental conditions (outside air temperature) Internal engine environment (cylinder head temperature) Each of these conditions must be known in addition to the information already "memorized" by the ECM. This is necessary for the ECM to perform the calculations necessary to deliver the optimum spark advance and fuel amount for each engine cycle for maximum performance as well as to meet government regulations for emissions. The method of how the required amount of fuel for any combustion cycle is calculated depends on the type of the EFI system. The three types of EFI systems are open loop, closed loop and combination open/closed loop systems. The first type of EFI system operates as an OPEN LOOP system. The ECM calculates and delivers spark and fuel based on a set of predetermined spark and fuel "maps." These "maps" provide the base information necessary to run the engine with only minor adjustments for external/internal environmental conditions. This method is accurate to the degree that the "maps" are accurate. The Harley-Davidson systems are open loop. The second type of EFI system operates as a CLOSED LOOP system. This system not only uses spark and fuel "maps" but also feedback from an exhaust gas oxygen (O2) sensor to continually adjust the amount of fuel delivered. This offers the advantage of "learning" the behavior of the engine over time as well as responding to a wider variety of conditions encountered while riding than that of an OPEN LOOP system. The Buell DDFI operates both as an OPEN and CLOSED LOOP system. This is necessary to adjust for all possible operating conditions. Buell's selection of high lift cams (which enhance engine performance) make it necessary for an open loop system at idle and wide-open throttle. Furthermore, when operating in open loop during cold start and idle, the system will utilize programmed fuel and spark maps in the ECM for ease of cold starting and to provide a stable idle. When the bike is at a steady cruising speed and operated under a light load, the DDFI system switches to closed loop operation. The system then continuously "tunes" the performance of the engine to compensate for changing conditions and provide maximum performance by using the O2 sensors input. General operating parameters for open and closed loop running. Return to Menu OPEN LOOP Idle and starting slow speeds under 20mph (1500 rpm) High speeds above 60mph (4,000 rpm) accelerating from low speed accelerating from high speed decelerating CLOSED LOOP Cruising between 40 - 60 mph at operating temp. (1500 to 3500 rpm) How does the Buell DDFI system work? Return to Menu The ECM uses six different sensors to monitor rider demands and changing engine conditions to determine the correct fuel and spark requirements. These sensors are: Throttle Position (TP) Sensor Cam Position (CMP) Sensor Intake Air Temperature (IAT) Sensor Engine Temperature (ET) Sensor Oxygen (O2) Sensor Bank Angle Sensor (BAS) The ECM needs the information from the TP and CMP sensors to calculate how much air is entering the engine. The TP sensor is attached to the throttle shaft on the left side of the throttle body. The CMP sensor is located in the gearcase cover on the right side of the engine. The TP monitors the amount of air entering the engine, by how far the throttle is open, whether it is opening or closing and how fast it is opening or closing. The ET Sensor provides the ECM the current engine temperature. Proper fuel and spark delivery are dependent on the temperature of the engine. The ECM will provide a richer fuel mixture on start up and a higher degree of spark advance. As the vehicle warms up to operating temperature the fuel mixture will lean and spark advance will decrease. The IAT sensor, mounted in the Helmholz Volume Power System (HVPS) air box, measures the temperature of the air entering the engine, when combined with the TP and CMP data the ECM can determine the density of the air entering the engine. The ECM also monitors the CMP sensor to determine the exact position of both cylinders in the combustion cycle and the engine speed. The fifth sensor is the Oxygen Sensor (02). It is desirable to operate the engine at or near stoichiometric, or approximately 14.6 parts air to one part fuel. The inclusion of the 02 sensor allows the ECM to ensure a proper air/fuel mixture is delivered to the engine by monitoring the final combustion efficiency in the exhaust system. This ensures optimum engine performance at any altitude. The sixth input is the Bank Angle Sensor (BAS). This sensor provides the input to the ECM that the vehicle is not leaning greater than a 55 degree lean angle. If the vehicle exceeds a 55 degree lean angle the BAS will interrupt the operation of the ignition system and the fuel supply. How does the O2 sensor measure the fuel mixture? Return to Menu An Oxygen sensor is a chemical generator. It is constantly making a comparison between the Oxygen inside the exhaust system and air outside the engine. A Zirconium stabilized yttrium oxide ceramic shell is coated with a layer of platinum. When the nose is heated the platinum will begin to react with the exhaust gasses and a voltage potential will form between the inner and outer layers. The sensor does not begin to generate it's full output until it reaches about 600 degrees F. Prior to this time the sensor is not conductive. This voltage output of the sensor is usually between 0 and 1.1 volts. A rich mixture leave very little free oxygen and the reaction will send out a voltage greater than 0.45 volts. If the engine is running lean, all fuel is burned, and the extra oxygen leaves the cylinder and flows into the exhaust. In this case, the sensor voltage goes lower than 0.45 volts. Usually the output range seen seen is 0.2 to 0.7 volts. The mid point is about 0.45 volts. This is neither rich nor lean. A fully warm O2 sensor will not spend any time at 0.45 volts. The O2 sensor is constantly in a state of transition between high and low voltage. Manufacturers call this crossing of the 0.45 volt mark O2 cross counts. The higher the number of O2 cross counts, the better the sensor and other parts of the computer control system are working. It is important to remember that the O2 sensor is comparing the amount of oxygen inside and outside the engine. If the outside of the sensor should become blocked, or coated with oil, this comparison is not possible. Also if the exhaust side of the sensor has been contaminated by using leaded fuels or gasket sealers which are not specifically identified as being approved for use with oxygen sensors the sensor can be permanently damaged. ADAPTIVE FUEL VALUE Return to Menu The Buell DDFI system has the ability to “learn” the engine fuel mixture needs. When the motorcycle is running in the closed loop mode and operated in a specific engine speed and load range, the system will compare the feedback from the O2 sensor to the base programming stored in the ECM. If a difference in these values is detected, the ECM will recalibrate the system program to compensate. This correction is termed the adaptive fuel value or AFV. This compensation value allows the system to adjust to different altitudes, air densities, and to some degree engine variations and wear. The normal AFV ranges based on altitude are between 85 and 115. The higher values are found at lower altitudes and the lower values at higher altitudes. The AFV correction is only applied to the fuel mixture during OPEN loop operation. During closed loop operation the O2 sensor signal is the primary compensation method. The AFV will be learned when the bike is operated at engine speeds between 2500 and 3500 rpm at road speeds in the 40 to 60 mph range under a steady light load (no down grades or steep upgrades, decelerating or accelerating) for 2 to 3 minutes. The AFV can also be reset to 100 by using the scanalizer at any time. The AFV value can be a valuable diagnostic tool. Compare the AFV values of bikes in your area which are running fine during routine services. When you are working on a bike which may have a DDFI problem, compare the values. If the AFV is higher than normal, the system is trying to correct for a situation which is causing the mixture to be too lean. Look for intake manifold or injector O-ring air leaks, incorrect ignition timing and TPS zero setting, low fuel pressure or a fuel line restriction as well as a sensor malfunction. If the AFV is lower than normal, the system is trying to correct for a situation which is causing the mixture to be too rich. Look for incorrect ignition timing and TPS zero setting, high fuel pressure or a leaking injector as well as a sensor malfunction. The O2 sensor can also cause the AFV to be set incorrectly. Internal shorts in the lead, poor electrical contact with the exhaust system or contamination can all affect sensor performance. O2 SENSORS CAN BE CONTAMINATED BY SILICONE SEALERS!!! ONLY USE SEALERS WHICH ARE LABELED O2 SENSOR SAFE IN ANY LOCATION WERE THE VAPORS CAN COME IN CONTACT WITH THE SENSOR. (top end of engine) IGNITION SYSTEM TIMING ADJUSTMENT - Cam position sensor adjustment (section 1.23 in 99/00 X1 service manual) Return to Menu The adjustment of the CMP sensor will effect fuel ratios and ignition timing over the full operating range. With the breakout box installed at the gray connector at the module, measure the voltage at pins 3 and 8 in the gray section of the breakout box. When the front cylinder timing mark is centered in the inspection hole, loosen the plate and turn it counterclockwise until the voltage drops to 0 vdc. Now slowly turn the plate clockwise until the voltage shifts to 5 vdc and tighten the plate. Keep the two plate attachment screws snug when performing this adjustment to reduce play. Take your time, recheck, accuracy is important. THROTTLE POSITION SENSOR ADJUSTMENT - TPS ZERO (not required when resetting idle speeds after initial calibration) Return to Menu FROM PAGE 4 OF BULLETIN B-017- section 4.33C in the 99/00 X1 service manual Verify Throttle Position Zero Setting Back out idle screw until it no longer touches the throttle plate stop. Back out idle screw one to two additional turns. Visually confirm that the throttle plates are fully closed. Connect scanalyzer to data link connector [91] with cable (Part No. HD-42921). Turn the ignition/light key switch to IGNITION. Turn the handlebar mounted Engine Stop Switch to the RUN position(but do not start the engine). NOTE: Observe that step 4 uses the standard diagnostic application cartridge and NOT the recalibration cartridge used previously. Insert diagnostic application cartridge (Part No. B-41325-99) into scanalyzer. During the next few seconds, the Scanalyzer sequences through a series of screens that reflect a power-on self test, the system copyright, and then an attempt at communications with the ECM. Once communications is established, the Diagnostic Menu appears on the Scanalyzer data display. Press number “3” key (Data Monitor) on scanalyzer and scroll down to last screen which has 3 Throttle Position (TP) readings. a. Open throttle to wide open throttle (95-100% open on first scanalyzer TP reading) and release throttle, allowing it to snap shut. b. Record Throttle Position Sensor voltage reading from scanalyzer. c. Repeat steps a and b a total of 3 to 5 times, recording voltage reading after each. • If the readings differ by less than 0.02V, go to step g. • If the readings differ by 0.02V or more, go to Step d. d. Open the throttle then gently force the throttle closed. e. Record Throttle Position Sensor Voltage reading from scanalyzer. f. Repeat steps d and e a total of 3 to 5 times, recording the voltage reading after each. • If the readings differ by less than 0.02V, go to step g • If the readings differ by 0.02V or more, replace the throttle body and repeat procedure from Step 1. g. Select mode #7 on scanalyzer menu. Select #1 re-zero TPS. A “calibration successful” message will appear. h. Press the mode key to return to Options Data Screen. Scroll to TP degrees. Turn idle adjustment cable clockwise until TP degree reading reaches 5.8. Press the mode key and press #3 to return to the diagnostic menu. Disconnect the Scanalyzer and turn the Ignition/Light Key Switch to OFF or LOCK. Turn the handlebar mounted Engine Stop Switch to the OFF position. Reset Warm Idle Speed DDFI Changes Service Bulletin B-029 Return to Menu New Rev limit function: Incorporates a skip spark feature. Resulting in extreme "hit", "miss" engine restriction. The ECM will now utilize the cylinder head temp as part of the equation to alter spark and fuel delivery. The MY2000 1/2 DDFI ECM protects the engine from extended operation at or near its limits for engine speed and cylinder head temperature by reducing available power and flashing the engine light on the instruments. This reduction in power occurs in successive stages: a mild (soft) spark/no-spark pattern, and an aggressive (hard) spark/no-spark pattern. "Soft" limit (speed or temperature): The ECM initiates a mild spark/no-spark cut. The ECM will also flash the Check Engine Lamp (CEL) to alert the rider when the engine temperature has exceeded a "soft" limit. "Hard" limit (speed or temperature): The ECM initiates the aggressive spark/no-spark pattern. If the rider should operate the engine near the "soft" limit the ECM will begin a countdown. If the rider persists in operating the engine near this "soft" limit and the countdown expires, the ECM will begin to operate as if the "soft" and, after another countdown, "hard" limits had been exceeded. Previous models offered only over rev protection by restricting fuel and backed spark advance down to '0' advance, resulting in lower performance. The new ECM does not retro fit to earlier models (pre-2000 MY). Buell Service Bulletin B-029 Glossary of Terms: Return to Menu Bank Angle Sensor (BAS) The Bank Angle Sensor senses if the motorcycle exceeds a 55-degree lean angle. The ECM uses this signal to shut off both spark and fuel delivery. Cam Position Sensor (CMP) The Cam Position Sensor consists of a Hall-effect device, magnet and plate. The plate is mounted over a rotating cup ("rotor cup" attached to the end of the camshaft. As the rotor cup turns inside the gearcase, six asymmetric "teeth" on the rotor cup sequentially break the magnetic field between the magnet and the Hall-effect device. The edges of these teeth are cut to correspond to specific positions of the camshaft during the engine cycle such as TDC for the front cylinder. The output of the CMP sensor is used by the ECM to determine engine position and calculate engine speed. This method of measuring camshaft position provides accurate information on engine position down to zero engine speed. Electronic Control Module (ECM) The ECM receives signals from the ET, IAT, CMP, 02, TPS and BAS. The ECM contains all the information needed to provide the proper fuel and spark mapping sequentially and individually to the front and rear cylinders of the engine at the proper time. Engine Temperature Sensor (ET) The Engine Temperature Sensor is located on the rear cylinder head near the spark plug. This sensor sends a signal to the ECM proportional to the current engine temperature. Fuel Pressure Regulator Valve Located on the fuel pump inside the fuel tank. The fuel pressure regulator maintains a constant 49-PSI fuel supply to the fuel injectors. The unused fuel is relieved inside the fuel tank. Helmholz Volume Power System (HVPS) Helmholz was a scientist who developed theories on air and sound motions. The Buell air box uses Helmholz principles combining his theories with the tuning of the intake duct and also effectively controlling the acoustics inside the air box. The Helmholz Volume Power System allows a small chamber volume to simulate a large area in terms of air movement, enhancing the engine performance, while reducing unwanted frequencies. Induction Module The Induction Module is located between the two cylinder heads. The Induction Module consists of a (43mm) single bore throttle body and intake manifold. The throttle body contains the TP sensor, manual idle speed adjuster, throttle plate and linkage for the throttle cables. The intake manifold contains the fuel rail and two fuel injectors. There is one fuel rail connecting the feed line to the injectors. Excess fuel is relieved by the Fuel Pressure Regulator inside the fuel tank. Intake Air Temperature Sensor (IAT) Located inside the Helmholz Air Box, this sensor sends a signal to the ECM proportional to the temperature of the air entering the engine. Manual Idle Speed Adjuster The idle speed is adjusted manually by turning the screw located on the right side of the throttle body. Pulse Width Pulse width is the amount of time a fuel injector is held open by the ECM. It is usually measured in milliseconds. Relative Air Density Air density effects how much oxygen is present within it. Air density is dependent on altitude (atmospheric pressure), temperature and relative humidity. Cool, dry air at lower attitudes contains more oxygen than warm, moist air at high attitudes. Horsepower is directly related to air density. Returnless Fuel System The Buell DDFI System is a returnless system, i.e.; there is no fuel return line from the fuel rail to the fuel cell. If fuel pressure should ever exceed 49 PSI, the excess fuel pressure is relieved inside the fuel tank by the Fuel Pressure Regulator Valve. Single Fire Coil The ECM controls the independent, primary windings of the spark coil. The ECM is thus able to provide sequential and independent firing of the spark plugs. | ||
| Id073897 |
OPEN LOOP Idle and starting slow speeds under 20mph (1500 rpm) High speeds above 60mph (4,000 rpm) Unfortunately DDFI-1 setup does not apply to the more recent ones. This document is almost ten years old, and it's content should be read with caution. All XB have idle closed loop enabled by default. The IAT sensor, mounted in the Helmholz Volume Power System (HVPS) air box, measures the temperature of the air entering the engine, when combined with the TP and CMP data the ECM can determine the density of the air entering the engine. This for example is complete BS as written here. The IAT allows to correct for air density changes *dependent on air temperature*, which has nothing to do with TP or CMP. As said before: learn the basics. Buell did not even manage to correct their manuals reagarding the oil plug torque, so why should the service bulletins be any better? | ||
| Iamarchangel |
Might be a good place to ask about the types of ECMs out there. My understanding, which I'd like corrected, is that there is the: '03 Stock/Race (same chip); '04-'08(early) Stock; '04-'08(early)Race; '08(later) Stock; '08 (later) Race When did DDFI-1 become DDFI-2? Was there a DDFI (no number)? | ||
| Spatten1 |
why can't Buell just tell us exactly how these things work, and eliminate all of our guesswork? Because they actually think someone would want to copy it, LOL. DDFI2 has no way to compensate for much of anything except to make quick corrections for the O2 readings. It eventually learns and updates the maps under some narrow parameters that Buell will not share either because they are embarrassed or because they think it is so ingenious that the other manufacturers will copy it. It is frustrating when the temp or altitude changes and you can't get the system to adjust because Buell will not tell you what the learning parameters are. Why I write this every 9 months or so, I'm not sure. | ||
| Id073897 |
When did DDFI-1 become DDFI-2? I have no idea. The earliest owner's manual I found mentioning DDFI-2 was for 2005 models, introduced in 2004 if I'm not mistaken. My owner's manual 2003 says just DDFI. I assume the first XB12 got DDFI-2 already, which would then be the GB231 ECM type. Was there a DDFI (no number)? Probably DDFI-1. The GB231 is the first one supporting an ABP sensor (via the AMC port), and the IB350 (factory race) is supporting a shifter configuration (via the BAS port), but I don't know, if the stock types do that too, or just the factory race module. The IB350 is also reflashable using a bootloader. I think DDFI-3 comes into play with the Thunderstorm engines, although the very early data seem more like DDFI-2. DDFI-3 fully supports shifter and ABP, not only as an alternative configuration. It also supports secondary injectors with a separate fuel map, camshaft and crankshaft sensors, fuel pressure sensor, 36-2 and 32-2 flywheels, adjustable VSS output, CAN communications, MAP sensor, load lookup tables (instead of TP only) and ... and ... and. This is a whole new world. | ||
| Id073897 |
DDFI2 has no way to compensate for much of anything except to make quick corrections for the O2 readings. Codswallop. All ECM types are capable to adjust fuel to all environmental conditions necessary. The developers and coders from VDO and IDS have done a tremendous job. | ||
| Blake |
I don't know why you write that "codswallop" every 9 months or so either Scott.  Seriously dude. Your view is unfounded. The Buell EFI system is as good or better than most that I've seen. | ||
| Spatten1 |
Blake, my issues have been primarily with rapid altitude changes, you don't have them in E. Tejas. Ask RaymondT about his bike going over Trail Creek pass last year. | ||
| Spatten1 |
All ECM types are capable to adjust fuel to all environmental conditions necessary Umm, the ones with MAP or baro sensors do. If DDFI 2 is so damn capable of this adjustment, why did they add sensors for DDFI 3? | ||
| Point_doc |
Al from American Sport Bike emailed me this info several months ago about the DDFI's. "DDFI-1 is the tube frame. DDFI-2 is the XB series. DDFI-3 is the 08 and later." Al | ||
| Blake |
Scott, You are making a huge assumption based on very limited information. I know for a fact that the ECM updates rapidly and handles altitude changes quite well. Too many Buells operating too well over altitude changes indicates the opposite of what you are asserting. | ||
| Id073897 |
If DDFI 2 is so damn capable of this adjustment, why did they add sensors for DDFI 3? Because people don't ride them the way the ECM could adjust. DDFI-2 requires to be operated in calibration mode to adjust to changing altitudes. | ||
| Id073897 |
DDFI-1 is the tube frame. DDFI-2 is the XB series. DDFI-3 is the 08 and later. Seems quite logical, although I'm wondering why Buell didn't name them like this in their early documents. | ||
| Spatten1 |
Because people don't ride them the way the ECM could adjust. DDFI-2 requires to be operated in calibration mode to adjust to changing altitudes. My understanding of the point of this thread is that Buell will not tell us what calibration mode is. We have to keep guessing based on antiquated DDFI 1 information. That is the source of my frustration. You are making a huge assumption based on very limited information. I know for a fact that the ECM updates rapidly and handles altitude changes quite well. Too many Buells operating too well over altitude changes indicates the opposite of what you are asserting. DDFI 2 adjusts fine for many riding styles, because they happen to coincide with the mystery calibration mode. It does not seem to adjust well at all for me when I'm riding hard up and down mountains at high RPM. Ray's bike nearly didn't make it over a 12k foot pass when we were in 15 mph traffic. His bike kept stumbling, and he had to nurse the clutch and throttle to keep it moving. I'm guessing calibration mode is somewhere in between these two situations, but Buell won't tell us, thus my frustration and attitude. | ||
| Swordsman |
Hmmm... that document Pkforbes87 posted has a lot of info in it...where did it come from? I already knew the gist of it, but mostly from picking up bits and pieces around Badweb, and what I've read in the ECMSpy guide. That document lays it all out nicely though. It explains why my bike takes on a different kind of vibration around 3500 rpms... according to the above, that's when the ECM switches from O2 readings to the AFV. So, I guess the big tuning challenge actually lies in the fuel maps, and trying to determine the amount of fuel vs. throttle position, and the relatively slow speed at which the sensors update (well, on DDFI-2, anyway). Any gremlins in the system will need to be addressed there. "The Buell EFI system is as good or better than most that I've seen." Blake, I was just wondering about all of this because the stumbling and surging seems to be one of the most common maladies complained about on the forum, and even in professional reviews (dunno about how the Xb debuted, but the 1125R fueling issues seem to be well documented by testers). Just train of thought, thinking about those problems and the people trying to figure them out, and the debates that happen here about the best way to go about it. Seems like if there was a concrete understanding of the system, a cure would be readily available. ~SM | ||
| Swordsman |
I still don't understand the need for the AFV. If the AFV is set by the O2 sensor, why not just use the O2 sensor the entire time? Does any other FI system use an AFV-equivalent calculation? It seems unnecessary. ~SM | ||
| Id073897 |
My understanding of the point of this thread is that Buell will not tell us what calibration mode is Calibration mode region is even shown in the ecmspy maps. The various values are described in the eeprom info pages. | ||
| Iamarchangel |
Proprietary Information. It's Buell's technology, they have a vested interest in the ownership of it. Every manufacturer has that. That being said, they don't seem to be too possessive about it. They've had several upgrades since the original and post updates through the year. These forums show it doesn't work for everybody but it looks like it works for the majority. It also seems that the weak link is at the dealer end, not the design itself. Buell is allowing it to stay fairly open, witness the open discussions, mapping, etc., of ECMspy. As stated already, there's lots of places to learn about it. | ||
| Id073897 |
t explains why my bike takes on a different kind of vibration around 3500 rpms... according to the above, that's when the ECM switches from O2 readings to the AFV. XB don't switch to OL at 3500 rpm. I still don't understand the need for the AFV AFV compensates for changes in air pressure for open loop regions. As mixture is different from stoich in most OL regions, O2 lambda correction is not applicable, but adaption to air pressure is required in every case. | ||
| Spatten1 |
If the AFV is set by the O2 sensor, why not just use the O2 sensor the entire time? It's for quick throttle transitions and WOT where you want to be slightly richer than stochiometric, where the narrow band O2 bias is really tough to regulate. Calibration mode region is even shown in the ecmspy maps. I don't have ECM spy. Why do we need to end run the factory to find out how to get our bikes to run properly? Umm, what are the parameters in ECM Spy? This might end my five-year rant! | ||
| Id073897 |
It's Buell's technology Honor to whom honor is due: it's VDO's technology (from what I found out). Now owned by IDS. | ||
| Iamarchangel |
Fair enough, I'm really talking ownership, not designer. Sources for understanding some of ECM: (first understand carburetion to understand what the ECM is replicating. Get familiar with the four stages idea: idle, low throttle, mid-throttle, full throttle.) Service manual (can be found online) Knowledge Vault (here) | ||
| Gemini |
afv is a learned value for that region of the bike. it will allow the bike to be close to "right" every time it goes back there. not having to relearn what it should be based off the o2 sensor. gives it a starting point when it gets back the closed loop area. that and keep in mind the o2 sensor is not at it's peak performance at all rpms ranges and temps. because of this, buell can professionaly tune the whole bike and sell it to you. in theory, when the closed loop learn area is a little rich, the whole map should be a little rich if the bike is unmodified. with that being said, because the o2 sensor works best in the area of closed loop learn, it will modify the afv and affect the whole map as needed....in theory. | ||
| Xoptimizedrsx |
JUST PUT WIDE BANDS ON IT AND CALL IT DONE. USE THE LC1 UNITS AND OFFSET THEM. EITHER USE THEM TO REMAKE THE FUEL TABLES TO YOUR BIKE THEN OFFSET THE CL TO 14.2 ON THE OUTPUT OF THE LC1 MAKING THE BIKE THINKS ITS AT 14.7. MAKE SURE THE UPPER TABLE ON OL IS NOT TO RICH. YOU WILL BE SURPRISED ON HOW FAR OFF THE MAPS ARE WITH THIS SETUP. FRONT AND REAR MAPS THAT IS. MIKE WORKS GREAT. MIKE | ||
| Jos51700 |
That big post by PKforbes is straight from Buell Tech training literature. Buell has been very open about how it works, it seems that people just don't want to accept it. It has never been a secret. Technically speaking, DDFI-1 never existed. It was just DDFI, until the DDFI-II debuted on XB's. | ||
| Iamarchangel |
Jos51700 Ha, was waiting for you to pitch in. (Message edited by Iamarchangel on January 02, 2009) | ||
| Spatten1 |
Calibration mode region is even shown in the ecmspy maps. The various values are described in the eeprom info pages. Id073897: Please post this information. | ||
| Id073897 |
Look at the website. |
