CFI ECU Tuning and Data Analysis Software

This is a follow on thread to my the 1985 Limited edition and 1986 SE-i Fuel Injection Motorcycles: https://classicgoldwings.com/thread...d-1986-se-i-fuel-injection-motorcycles.14941/. I enjoy anything EFI.

This thread will look at the tuning software, Tuner Studio, and data analysis software, MegaLogViewer (MLV). These software applications, licensed versions are powerful tools that allow the user to calibrate/configure/modify the engine tune for maximum engine performance and fuel economy. The existing CFI system, especially the engine tune, is a compromise resulting in good street performance and fuel economy.

These software applications in conjunction with an aftermarket ECU provides the rider/user with the ability to better tune the engine for performance and fuel economy, and address operation issues. The ability to have access to the various features/functions of the ECU is a game changer with these motorcycles, considering that this ability has not been available to the rider/user to date. This is not to say that a rider/user would delve into this, but it would be available.

Discussing these software applications should give riders with an FI motorcycle, or cars/trucks for that matter, a good insight into an EFI installation. How the fuel injectors are controlled, how does the battery voltage affect the FI system operation, and so on.

This thread is for information only, and maybe, be a tipping point for many who may think about undertaking an EFI conversion, or doing an upgrade/modernization project because access to the existing ECU is not available. This is not to say that changing to an aftermarket ECU guarantees the user access to the tuning software, data analysis applications - may be a proprietary issue.

I am the primary recipient of the benefit(s) from doing a thread such as this as I use the TS and MLV software applications on a regular basis. The more I delve into these software applications, the more I learn how these software applications enhance the engine tuning experience.

Enough of a preamble. Cheers

The engine tuning, Tuner Studio (TS), and data analysis, MegalogViewer (MLV), software applications, are from EFI Analytics. These software applications, the licensed versions, are powerful tools that you use to do the engine tune, and analyze the engine performance data.

Starting with Tuner Studio. This software application is where you begin the engine tuning process. A significant amount of component data is required to start the project engine tune. There are accepted EFI components that are used in many EFI conversion/installations, and because of this, there is component data available for your project.

Using EFI components that are not regularly used, or are components of an OEM proprietary system and you have no component data, will result in an experimentation process to "dial" in the component in question.

There are generic data settings recommended for most EFI components from which you can start the engine tuning process, after which you will have to proceed with an experimental process to "dial" in the EFI component in question.

The VE(fuel), spark (ignition timing), and AFR tables will need to be populated/calibrated as you start the engine tuning process. There are "wedge" tables used for this process. This where table cell values are estimated and used to do an initial engine start.

The VE (fuel) table is the most important of the three tables used for normal engine operation. The cell values represent a percentage of the total amount of fuel required for wide open throttle (WOT)/full power operation. For example, a cell value of "35" represents a fuel requirement of 35% of the 100% fuel requirement. This cell value and other system parameters are use to calculate the required fuel for a given MAP/RPM reading.

On initial engine start, the VE(fuel) table cell values may not be what is required and you will have to adjust the cell values to suit. The Speeduino forum collective agrees that the first order of business is to get a handle on engine feeling at idle and normal operating temperature. This is done by changing the VE table cell values to provide the required fuel at idle. When you adjust the cell values it must be remembered that the lower the cell value. less fuel will be injected into the engine leaning out the air-fuel mixture, a larger number will result in more fuel being injected into the engine creating a rich air-fuel mixture.

Another truism is to give the engine what it wants. This means that you give the engine the require fuel and ignition timing for a specific MAP/RPM combination. To do this you first adjust the VE table cell values, up or down, then adjust the ignition timing to suit. You continue to do this until the engine has what it needs.

Ignition timing is relatively straight forward when dealing with the original OEM installation. You ensure the crank and camshafts are aligned properly, then if so inclined you can use a timing light to ensure the idle timing is in accordance with the OEM specifications. Having done this there are no further engine timing checks to be done, timing is now fixed as per the OEM design.

The challenge is to try and mimic the OEM CFI system operation. Honda's CFI system design uses a set of EFI components that Honda has made work and work well. Component data is non-existent so a WAG may be required.

Initial ignition timing is 10 degrees BTDC at approximately 1000 RPM, and full advance is 45 degrees BTDC, no RPM specified. This is also predicated on a fuel system operating pressure of 28 to 32 PSI. The fuel injectors are rated at 284 cc/min or 315 cc/min depending on the servicing shop. You will have to enter a derated fuel injector value in the engine tuning software to get close to the original engine operation.

The OEM VE and spark tables are a compromise resulting in good engine performance and fuel economy. Having the ability to adjust/modify/calibrate the engine tune can result in better engine performance and fuel economy.

My '85 1200 GW FI model is capable of achieving a fuel economy of 45 to 50 IMPG. This indicates that the engine is using approximately 5 litres per 100 Km, a lean air-fuel ratio. This is an operation parameter worth aspiring to.

The engine tune that you may settle on, may not be as envisioned, or as per the OEM design specifications.. Engine timing may be significantly different.

The AFR table is not used during the initial engine tuning phase, only after you have a well calibrated VE and spark tables. You should, when changing to a new aftermarket ECU, install a wide band oxygen sensor (WBO2). The WBO2 sensor provides an indication of the air-fuel mixture, how rich or lean the engine is operating, and assist in adjusting/calibrating the VE and spark tables. Calibrating/adjusting the VE and spark tables can be done without a WBO2 sensor, but is more challenging. This table can be populated in its entirety with generic cell values of 14.7 at the onset.

There are a number of engine tuning parameters that do not need to be used at the onset of the engine tune. These parameters that will be discussed as this thread progresses, should be disabled or turned off, and only enabled/turned on after the initial engine tune is done.

This post sets the stage for the what will follow in this thread. MegaLogViewer will be discussed as well and how it complements the Tuner Studio software application.

Having access to an engine tuning software may bring into focus an old idiom "ignorance is bliss". I mention this because the information available to the user can bring into question what the engine performance is. There are a significant amount of settings/parameters/features/functions that you get to "play" with. A disciplined approach is need to keep oneself from going down the proverbial rabbit hole whenever the way ahead is not going as one would like. Another idiom is BTDT, I have been the recipient of this, self-induced mind you.

Cheers

Started the review of the Tuner Studio (TS) software application last night. There are information buttons throughout the application describing the feature/function and if it relates to another feature function. A "note" button may also be included so that you can detail what you have done to that specific function feature. Easier than keeping a paper journal especially when tuning the engine and you want to capture your thoughts immediately. This is a page I will discuss in detail:

You can see the info and note buttons to the left of a parameter. Not all parameters have these. My review of this page was an interesting learning experience. The more advanced tuners on the Speeduino forum give advice on what to do with regards to an engine tune, but sometimes the context is not. For example, Injector Staging - settings Alternating or Simultaneous. Alternating is the normal setting; however, when the sequential setting is chosen for Injector Layout, the Injector Staging parameter is not used. The Squirts per Engine Cycle is another parameter that has a hidden issue. My setting is for "2" Squirts per Engine Cycle; however, when I use sequential feeling, the software converts this to "1" Squirt per Engine Cycle - had to ask the question.

Choosing a semi-sequential fuel injector layout brings another drop down box to the fore - not there when using the Paired fuel injector layout - only used with semi-sequential fuel injector layout. This new drop down box allows you to choose the paired injector layout for your specific application. There is a 1+3 and 2+4 fuel injector pairing that the 1200 GW requires.

These tuning software idiosyncrasies can be daunting for us new to this world. I have learned from a lot from the school of hard knocks as have others, but I would think that a more detailed user manual would be beneficial.

I am going to have to do more research into this semi-sequential fuel injector layout. Was reading my original Speeduino thread last night, and it was an interesting sometimes amusing read.

Interestingly, I found a post from the initial engine starts that mentioned that the dash tach was working. The configuration was paired fuel injectors and wasted spark. The tach output is from numbers 1-3 fuel injectors, through the Travel Computer to the dash. The Travel Computer uses this signal for the fuel management system, maybe a couple of other features as well.

Cheers

I use Tuner Studio MS as it has all the options I want, the only tuning application for the Speeduino ECU, and is a licensed version. Licensed versions are recommended because there are features/functions not available to a user with a lite version.

The Speeduino manual details how to download the firmware and base engine tune, and then how to connect to the TS application and start a project. This part of the project will not be discussed in this thread.

Once you have the project started in TS, you will need to populate the various parameters with the relevant information. When you start a project such as this, you should have as much component data available for input.

The first page to be discussed is Engine Constraints:

I have mentioned that there are parameters that have an info and note button relating to the parameter. Good place to make notes regarding changes, performance impressions and the likes.

It is to be noted that your starting parameter settings are a starting point for the engine tune. You can change any of the parameter settings to fine tune the engine tune as it progresses, if the change is for the better, keep it, if not revert back to the original setting.

I’ll discuss the separate parameters first then do Required Fuel (RF).

Control Algorithm: This is what component will be used throughout the engine tune. The choices are manifold absolute pressure (MAP) and throttle position sensor (TPS). MAP is the common controller, more so than TPS. Configuring the engine tune using MAP to represent the engine load is more exacting and easier in my estimation, I have tried both. Using MAP for the engine load has the engine tune using Speed Density (SD) for the fuelling profile. When using MAP for engine load, the TPS is used by the ECU to indicate when the throttle plates are closed (relatively), and when the throttle is being opened, other than this, the TPS has no other function.

When using the TPS for engine load, resulting in an Alpha-n (AN) fuelling profile, the MAP sensor is not used by the ECU unless you use it for another feature/function such as Acceleration Enrichment. Alpha-n fuelling profile is common with the throttle body injection (TBI) crowd.

Squirts per Engine Cycle: An engine cycle is two revolutions of the crankshaft – 720 degrees. The number of squirts range from 2 to 8 squirts with 2 or 4 squirts being most common.

Injector Staging: Whether or not the fuel injectors are fired at the same time or at alternate times. This setting is ignored when sequential fuelling is selected for Injector Layout, but is included in the RF calculation.

Engine Stroke: self-explanatory, 4 or 2 stroke.

Number of Cylinders: self-explanatory.

Injector Port Type: Port or Throttle Body (TBI). Port fuel injection is one injector per cylinder. Fuel injectors are located close to the intake valve and spray fuel at the intake valve. The 1200 GW FOI models use port fuel injection. TBI is for shared fuel injectors. When choosing this setting, know what you have installed, and realize the difference(s). I will be discussing the difference between these two fuel injection configurations in a separate post.

Number of Injectors: depends on the Injector Port Type.

Engine type: Even or Odd Fire. Even Fire is for engines with an even number of degrees between cylinder firing – most engines. Odd fire can be for engines with an even number of cylinders, or not. A parameter setting you must know when setting up the project.

Board Layout: Very important that you get this correct. The base Speeduino “.ini” file has “case” files that indicate the pinout that applies to the Speeduino interface board in question.

Stoichiometric Ratio (xxx:1): generally 14.7.

Injector Layout: three choices, Paired, Semi-sequential, Sequential. Paired fuel injector are two fuel injectors on the same circuit – may also be called “Batch” fuel injection.

Semi-sequential fuel injectors is similar to a Paired fuel injector layout except that each fuel injector is on its own circuit up to a maximum of 4 injectors. This is unless you have more than four cylinders and two injectors per injector circuit is required. See the Speeduino manual for further information. Selecting semi-sequential fuel injector layout, a new drop-down box will appear. This drop-down box has two fuel injector settings. The one for the 1200 GW is 1+3 and 2+4. The second setting is 1+4 and 2+3. Choose the correct setting. This is where the Paired fuel injector layout and the Semi-sequential fuel injector layout diverge. The ECU uses this setting, in the case of the 1200 GW 1+3 and 2+4 to fire the fuel injector circuits for fuel injectors 1 and 3 at the same time and fuel injector circuits for fuel injectors 2 and 4 at the same time. This is sometimes referred to as “mirroring” individual circuits. Once you choose the correct setting, the ECU will fire the appropriate fuel injectors at the same time.

Sequential fuel injector layout is where each fuel injector is on its own circuit, and fires in sequence, injector 1, injector 2, injector 3, injector 4. You must ensure that the appropriate cylinder fuel injector is connected to the correct fuel injector circuit. For example, the firing order for the 1200 GW is 1-3-2-4. In this case, cylinder 1 is on injector 1 fuel injector circuit, cylinder 3 is on injector 2 fuel injector circuit, cylinder 2 is on injector 3 fuel injector circuit, cylinder 4 is on injector 4 fuel injector circuit. Make sure the engine cylinder timing is taken into consideration when connecting for sequential fuel injection.

MAP Sample Method: This is where you choose how the MAP sensor reading is used. For more than 2 cylinders, Cycle Average is recommended. The ECU will take several MAP readings, average these and use the average for the different engine tune calculations. For up to 2 cylinders, Cycle Minimum is recommended. This where the ECU takes several readings and uses the lowest reading for the engine tune calculations.

MAP Sample Switch Point: This is the engine RPM setting below which the MAP inputs are considered to be instantaneous.

Odd Fire Angles will not be discussed as I am not familiar with these at this time.

Required Fuel (RF) Calculation:

This box indicates the base fuel injector time to achieve a 100% stoichiometric ratio at a MAP reading of 100 kPa using the settings input on the Engine Constraints page and Required Fuel Calculation drop-down box:

The settings shown are for my 1200 GW FI model, yours may be different depending on your configuration. These settings along with the setting on the Engine Constraints page are used to calculate the RF in ms shown in the Calculate Required Fuel box. The number of squirts will affect the second box on this page. For example, if the RF is calculated to be 6.2 ms and you use 2 squirts per engine cycle, the value should be 3.2 ms, divide by 4 squirts – the value should be 1.8 ms. You can change the number of Squirts per Engine Cycle as the engine tune develops to fine tune your engine tune.

You can also change the RF value manually. This will perform a “global” change to all the VE (fuel) table cell values.

Cheers

Port versus Throttle Body (TBI) fuel injection. Needs to be understood. It’s a great topic to research as there is a significant amount of information on-line to read, videos to view, and EFI installations that use one or the other.

A bit of history is required. Carburetors were the choice of the day, but have ben put out to pasture when EFI was adopted as the way forward – emissions legislations. Single point of fuel, maybe more, remember the 2-barrel 6 pack Mopars! Aftermarket plenums to enhance the engine performance, all kinds of performance parts available.

Enter EFI, starting with TBI. A definite upgrade to using a carburetor. Engine coolant and air inlet temperature were being considered, battery voltage compensation, and a host of other parameters were now being considered for engine performance and fuel economy.

Throttle body fuel injection was available when I was into modifying older car fuel systems back in the ‘70s/’80s.

This was and is an upgrade from a carbureted fuel system; however, you still have the same issues with sharing the fuel injector with multiple cylinders, fuel injector size – do you use 1, 2, or more fuel injectors, plenum wall wetting – fuel puddling, engine tuning for cold starts is more challenging, the intake plenum may or may not be conducive to a TBI installation.

Step up to Port fuel injection, this is used on the ‘85/’86 1200 GW FI models. The fuel is injected by the fuel injector almost directly at the intake valve – one fuel injector per cylinder, generally called multi-port fuel injection. Concerns such as wall wetting – fuel puddling is minimized or eliminated, fuel injectors are sized to inject the appropriate amount of fuel for a single cylinder, cold start engine tuning is easier, may need to fabricate a fuel injector manifold, and so on.

These are tried and true fuel injection profiles. Whichever fuel injection profile you use - each has merit depending on the application, the correct setting must be used in Tuner Studio.

Update on Paired fuel injection layout. This is where the ECU fires two fuel injectors at the same time – mentioned in my previous post.

For example, the ‘85/’86 1200 GW FI models have a cylinder firing of 1-3-2-4. Fuel injectors 1-3 are fired at the same time, 2-4 fuel injectors are the same. To minimize fuel loss, fuel injector pairing must be such that the fuel injected is used in firing order sequence. Fuel is used in cylinder 1 immediately, then in cylinder 3 almost immediately, happens very quickly in milliseconds. Not a lot of time to lose the fuel charge, if at all. Same happens for cylinders 2-4.

This translates into the ‘85/’86 1200 GW FI model ignition system and why it is configured the way it is - coil pairing is cylinders 1-2, and cylinders 3-4. Coils need to be charged after being used to ignite a cylinder air-fuel mixture. The coils are set up for wasted spark. When coil for number 1 cylinder is firing, coil for cylinder 3 is charging. When coil for number 3 cylinder is firing, coil for number 2 cylinder is charging. When coil for number 2 is firing, coil for number 4 cylinder is charging. When coil for number 4 cylinder is firing, coil for number 1 cylinder is charging, and the cycle repeats itself. Relates directly to the fuel injector firing sequence.

This is true for all the older GWs, ignition firing sequence may differ, but the concept will be the same.

Cheers

Let’s discuss fuel injectors. Under the Settings/Injector Characteristics tab:

Injector Characteristics: Injector Duty Limit percentage (%) – the accepted setting for this is approximately 85% for us laymen. This indicates that a full power/WOT the fuel injector will be at 85% of the full opening of the fuel injector. If the Duty Limit is at 100%, the fuel injector will be flowing max fuel and not responding to the ECU calculated pulse width. A balancing act to be sure.

Injector Open Time: commonly called Dead Time. The fuel injector is a small coil that when energized pulls a valve off a seat and lets fuel flow. Once the fuel injector is deenergized, the valve falls back onto the seat and fuel flow stops. The time it takes to open the fuel injector valve, no fuel flowing and the time it takes to strop the fuel flow is called the “Dead” time.

For example, the “Dead” or Opening Time is a calculation using various parameter settings, one of which is this one. If the required fuel injector pulse width is 3.0 ms for a specific power range, and the “Dead”/Opening Time is 0.8 ms, the actual fuel flow time is 2.2 ms. It takes time to open/close a valve of any sort.

“Dead”/Opening Times vary depending on the fuel injector in question which is why it is important to have the specific fuel injector data available.

There are service shops that specialize in providing fuel injector data. You will still need to experiment with the “Dead”/Opening Time after fuel injector installation to fine tune the fuel injectors for optimum flow and engine performance. Recommended opening times can be from 0.5 to 1.2 ms with a start point of 1.0 ms. You want the fuel injector to be fully open when fuel starts to flow. Too short a “Dead”/Opening Time and not enough fuel will flow for the required pulse width – early lean air-fuel mixture, too long a “Dead”/Opening Time and fuel flow will not be at the optimum time, late rich air-fuel mixture. Something like ignition timing, too advanced and the engine operates with a lean air-fuel mixture, too ******** and the engine operates with a rich air-fuel mixture. Everything goes hand in hand.

Battery Voltage Correction Mode: This can be applied to the whole fuel injector pulse width, or just the “Dead”/Opening Time of the fuel injector pulse width. This mode monitors the battery voltage so that when the battery voltage is less than 12 VDC (12 VDC is used as the reference for this correction) the fuel injector pulse width will be increased to compensate for this – needs more pulse width time to do the job. Conversely, when the battery voltage exceeds 12 VDC, the fuel injector requires less time to do its job and the fuel injector pulse width is decreased.

Injector Close Angles: You can adjust the fuel injector close angle to optimize when the fuel injector will stop injecting fuel. This setting is in degrees ATDC. An accepted value can be from 100 to 160 degrees ATDC, this should coincide with the opening/closing of the intake valve on the intake stroke, experimentation will be required to fine tune this setting. The intake valve opens drawing in the air-fuel mixture, closes and compresses the air-fuel mixture, and at the specified ignition timing – ignites the air-fuel mixture.

Changing this setting so that the complete fuel charge is injected and ingested into a cylinder can result in a rich air-fuel mixture. You may have to reduce the VE (fuel) table cell values to bring the air-fuel mixture back into line for the required AFR. In laymen’s terms, same power using less fuel, possibly better fuel economy.

There is a parameter for sequential fuel injection called Individual Cylinder Fuel Trim. This feature allows you to calibrate an individual fuel injector to “balance” each cylinder so that each cylinder does the same amount of work.

Follow-up on the above post. The Injector Close Angle is ATDC. It is recommended that this parameter be calibrated after the engine VE table is well calibrated. As mentioned above, once the VE table is well calibrated and you decide to calibrate the fuel injector close angle, you may have to adjust the VE table calibration. Will be doing research into this because it would make sense to do an initial calibration close to what is needed, then continue with calibrating the VE table. Have a spare engine, don't ask, and I will be determine when #1 cylinder intake valve opens (use a degree wheel) so that an initial fuel injector close angle is determined and used. I would expect it would be correct to have the fuel injector close angle such that fuel injection is finished before the intake VV opens, or as close as possible, knowing that fuel does not stop immediately once the fuel injector pulse width is finished.

The fuel injector close angle will change with varying engine power ranges. The benefit of this parameter is at idle and low power levels. The injector close angle at high powers/engine RPM its not as critical because the time between fuel injector pulse widths happens so quickly that the fuel injector is probably more open than closed.

Cheers

Next instalment, Trigger Settings.

Trigger Settings: This is all about engine timing. You define the trigger patten, and all parameters associated with this. The trigger settings are a critical set of parameters that needs to be as accurate as possible before an engine start, if not the engine may kickback because engine timing is not correct, poor idle control, and a host of other issues. The Trigger Settings dialogue page:

There are many different trigger patterns depending on your application and more are being added.

Trigger Pattern: There are three primary trigger patterns, Missing Tooth, Basic Distributor, and Dual Wheel.

Missing Tooth: This is where you have a trigger wheel that can be divided into 360 equally. A missing tooth trigger wheel decoder system provides the ECU with an indication of the crank angle ATDC when tooth #1 passes the crankshaft sensor. This is critical for a Speeduino ECU. This decoder system allows the ECU to guesstimate the engine timing with relative accuracy but not with the accuracy of a dual wheel system.

Basic Distributor: A very basic decoder system that provides the ECU with inputs similar to a traditional distributor output.; ie: one pulse per cylinder cycle. This decoder system cannot provide the ECU with any accurate cylinder position, and as such should be used with a crankshaft missing tooth trigger wheel, or a camshaft signal reference so that Speeduino can calculate the crankshaft angle, cycle phase or cylinder assignment. It is available, but not as prevalent as in days past.

Dual Wheel: This is the best of all worlds. You have a crankshaft trigger wheel and a camshaft trigger wheel. The camshaft signal can be from any part of the engine as long as the signal to the ECU is half that of the crankshaft sensor. The crankshaft trigger wheel can be a missing tooth trigger wheel or a trigger wheel with no missing tooth.

Primary Base Teeth: Settings define the number of teeth on the primary trigger wheel. This could be the exact number of teeth on a non-missing tooth trigger wheel, or the number of teeth on missing tooth trigger wheel. When defining the number of teeth on a missing tooth trigger wheel, include the missing tooth as well.

Primary Trigger Speed: This setting defines which trigger wheel takes precedence, is leading – crank or camshaft.

Trigger Angle (deg): This is where tooth #1 passes by the crank or camshaft sensor in degrees. It is an estimated setting, and the actual trigger angle must be confirmed with a timing light before the first engine start. Defining the Trigger Angle is documented in the Speeduino manual and there are a plethora of Speeduino forum threads, and other forum threads related to determining the Trigger Angle.

Skip Revolutions: this setting is where you define how many engine revolutions will be skipped before the fuel injectors and ignition coils are fired.

Trigger Edge (primary trigger wheel): this setting defines which edge of a trigger wheel tooth is used by the ECU, rising-Falling. A rising trigger edge is where the signal output used by the ECU is on the leading edge of a trigger wheel tooth – signal increase. A falling trigger edge is where the signal output used by the ECU is based on the trailing edge of the trigger wheel tooth – signal decrease.

Secondary Trigger Edge: This setting defines which edge of a trigger wheel tooth is used by the ECU, rising-falling. This setting is generally the camshaft speed signal to the ECU.

Trigger Filter: This setting allows the user to set a filter that removes system noise. The options are: OFF, Weak, Medium or Aggressive. The more aggressive the filter, the more system noise is filtered. There is a possibility with an aggressive setting that some true readings could be filtered out. A medium setting is recommended for most applications.

Re-sync Every Cycle: options – ON/OFF. If turned ON, engine sync will be checked every full cycle (2 camshaft revolutions) from the camshaft sensor. If no camshaft sensor, setting should be OFF.

Engine sync is caused by a signal loss from ether the crank or camshaft sensor. There are a multitude of reasons for this such as misfires, poor timing, crank or camshaft sensor(s). It is necessary to rectify any sync loss before progressing the engine tune.

Cheers

The information I am passing on is directly related to the various pages in Tuner Studio (TS) that I am familiar with and are, IMHO, most relevant. The information presented is from the page(s) being discussed, and amplified with my understanding of the page in question. A small disclaimer as I am not the author of most of the information being presented.

There is a fellow on the Speeduino forum from Toronto. He is having a difficult time deciphering the TS software application. I feel his pain because I have and still have issues with understanding the TS application, getting better at it. This thread and others that I am the author of help further my understanding of the TS application, an EFI system, and the engine tuning process.

Cheers

Injector Close Angle, a Reader's Digest version

Tuner Studio (TS) for the Speeduino ECU allows the user to determine the fuel injector end time. This is the point in the engine cycle, 2 crankshaft revolutions, in degrees (up to 720°) when the fuel injector will stop flowing fuel to the cylinder. This can be closed valve injection (CVI), open valve injection (OVI), or a combination of both.

Research will provide you with a wealth of information, and pros and cons. This post is not all encompassing and I encourage EFI users to investigate further.

There is one setting in TS for this parameter, and each cylinder fuel injector end time, when the fuel injector will be deenergized, will be in accordance with this setting. Other ECU tuning software applications may have different settings. For example, TS for the Mega Squirt family of ECUs has a three settings that can be chosen; start, middle and end.

Closed valve injection, when the fuel injector is timed to have the fuel flow stop before the intake valve opens, is advantageous from a fuel atomization perspective. Atomization will depend on your fuel injection layout, TBI or Port (most common and popular).

Port fuel injection sprays the fuel charge directly onto, or as closes as possible to the intake valve. The intake valve is generally the hottest component in the cylinder head, and as such, the fuel charge should atomize quite well. Having the fuel charge completely atomized will ensure that when the intake valve opens, the maximum amount of fuel will be drawn into the cylinder.

Open valve injection is when you time the fuel injector stop point (de-energize the fuel injector) to be close to or just when the intake valve closes. Theoretically this can be anytime during the opening/closing of the intake valve. There are advantages to using OVI, one being that the fuel charge helps cool and lubricate the cylinder for piston travel. I would surmise that this is not a deciding factor. A disadvantage is trying to have the entire fuel charge in the engine cylinder before the intake valve closes, not a lot of time probably in milliseconds. I submit that this is almost impossible considering how the fuel injector works.

I would think that a combination of CVI and OVI would be more practical, overlapping with the majority of the fuel charge being injected when the intake valve is closed for maximum fuel atomization, and considering that when the fuel injector is deenergized, it still takes a bit of time to fully close and stop fuel from flowing.

A generic setting for fuel injector end time is 360 degrees. This degree setting has the cylinder fuel charge in the runner at the intake valve being atomized before the intake valve opens, and having the fuel flow cease as the intake valve opens or shortly thereafter. A good setting for most of us. The picture attached illustartes this:



This parameter setting can be changed after the engine tune is done. Changing this setting to fine tune engine performance and fuel economy may result in recalibrating some of the VE and spark table cell values. The take away for this parameter is that you want to give the engine what it needs for best engine performance and fuel economy, experimentation will be the requirement.

I have viewed YouTube videos regarding fuel injector close angles, and the results are interesting. Depending on the engine, how “tricked” out the engine is or not (stock), determines what setting is good for your engine. Even though we may have the ability to tune this parameter, most of us never will.

This is the Reader’s Digest version of fuel injector close angle, but another piece of the EFI puzzle as I understand it.

Skill testing question, anyone remember this picture form school. I do, but have not had to use it since the '70s:



Cheers

Review of various forum thread posts resulted in questions being asked about Oddfire Angles. This is where an engine has different cylinder firing angles.

To input Oddfire Angle settings, you set Engine Type in the Engine Constraints section to "odd fire". This enables the Oddfire Angles for up to four cylinders in the bottom right section of this tab/page:

Even or odd is simply whether the firings are evenly divided in the 720° cycle; e.g., 4-cyl even fire at 0-180-360-540, or uneven/odd; e.g., 0-200-360-560. Cylinder 1 is always 0°.

There are quite. few threads and posts regarding this issue on the Speeduino forum. Another example as to the versatility of the Speeduino platform.

Another forum/discussion web site is "Discord" at discord.com. There is a Speeduino section and it is quite involved. Topics being discussed range from hardware, components, development, board design and more. Worth looking at especially if you are an insomniac - bedtime reading.

Continuing with the Tuner Studio (TS) analysis. The next tab to be discussed is “Tuning”. Once you have the initial engine parameters set, time to understand the engine tune parameters. I am discussing the Tuner Studio features/functions as I understand these for the Speeduino ECU. Most of this information is available in the Speeduino Manual; however, I do notice that the TS application has parameters/settings not included in the Speeduino Manual.

This section on Tuning is quite involved and will require several posts to cover. I believe I have mentioned that this review of Tuner Studio is very beneficial for myself.

The various sections for engine tuning in the Tuning tab are:

• Realtime Display
• Acceleration Enrichment
• AFR/O2
• Engine Protection
• Flex Fuel
• VE Table
• Spark (ignition timing) Table
• AFR Table
• Second Fuel Table
• Second Spark Table
• Sequential Fuel Trim (1-4)
• Sequential Fuel Injection (5-8) (grayed out)
• Staged Injection
• Fuel Temp Correction (grayed out)

Real time Display: as the title indicates it is a display of the essential engine parameters. Have not looked into this display and admit my understanding of how to change the settings is not known.

Acceleration Enrichment: This parameter is similar to the carburetor acceleration pump. This parameter prevents the engine from “bogging” when you try to accelerate quickly to preventing the engine from operating with a lean air-fuel mixture, and from being starved for adequate fuel. Acceleration enrichment should be enabled when the VE, spark and AFR tables are well calibrated.

This is a picture of the AE section:



Acceleration enrichment (AE) is used to add extra fuel during short transient periods following a rapid increase in the engine throttle. This parameter is used to accommodate the period of time the ECU needs to adjust to the new engine load, as determined by MAP or TPS.

This parameter is user defined and based on the rate of change of the throttle position (TPS) called TPSdot, or the rate of change of the MAP called MAPdot. This is measured in %/s, % being the rate of change of the throttle over a specified time period. Higher TPS values represent the faster the throttle is opened.

TPSdot or MAPdot is represented on the “X” axis, the “Y” axis represents the % increase in fuel.

Tuning: To tune AE, you need to have your VE, spark and AFR tables fairly well calibrated. It is recommended that you set the Taper Start RPM and Taper End RPM settings to a value above the engine maximum RPM. Fast and slow “blips” of the throttle are to be used and the effects on the AFR reading(s) monitored. If the AFR reading is initially good before the throttle is “blipped”, but goes briefly lean, increase the Accel Time setting in 10-20 ms time increments. The theory is that you do not want the engine to go into a lean fuelling condition.

False Triggering: This is where there is a noisy TPS signal that can cause triggering of AE when not required. To compensate for this, it is recommended to increase the “TPSdot Threshold (%/s)” in ~5%/s increments, doing a test/trial and determine if the change is sufficient to compensate for the false trigger of AE, if not, increase this setting until AE is no longer being triggered when not required.

Settings for Acceleration Enrichment are user defined as follows.

Enrichment Mode: is related to using the TPS or MAP sensor for engine load and AE; choices are TPS or MAP.

Enrichment Method: PW Adder – the ECU adds the extra amount of fuel required as a percentage to the fuel injector required pulse width according to the AE TPS or MAP based AE graphs.

PW Multiplier: the ECU multiplies the required fuel injector pulse width by the extra amount of fuel in percent to determine the required fuel injection pulse width in accordance with the AE TPS or MAP based AE graphs.

TPSdot Threshold: Percentage of throttle change per second required to trigger AE. For example, if this setting is at 60, the throttle position must change at a rate of 60% per second to trigger AE.

MAPdot Threshold: Same as for TPSdot except that it is the percentage of MAP change per second that triggers AE.

Acceleration Time: Duration of AE in milliseconds once AE is triggered.

Taper Start RPM and Taper End RPM: This is the RPM, at normal engine operating temperature, that AE will start to be reduced, scaled linearly, until the Taper End RPM is reached. It is expected that AE will be 100% for all RPM values less than or equal to the Taper Start RPM, and at 0% when the RPM is greater than or equal to the Taper End RPM.

Acceleration Enrichment Cold Adjustment: Scales the AE percentage linearly based on coolant temperature. User defined setting for Cold Adjustment Taper Start Temperature and Cold Adjustment Taper End Temperature.

Deceleration Fuel Cut-off (DFCO): Stops fuel injection in accordance with user defined settings when enabled. The following settings relate to DFCO.

TPS Threshold (%): The TPS percentage below which DFCO will be active.

Minimum Engine Temperature: Minimum engine temperature required to enable DFCO.

Cut-off Delay (s): The time to delay the enabling of DFCO.

Cut-off RPM: The RPM above which DFCO can be enabled.

RPM Hysteresis (RPM): An RPM value that is used to compensate for RPM fluctuations at various engine loads when DFCO can be enabled.

As I discuss the TS software, I realize that the design engineers back in the day had an uphill "battle" to get the first GW engine tunes up and running. Can you imagine being on the design team and doing the "what if" scenarios. What are the requirements and what do we want to achieve, do we need to use this, shouldn't this be included, ascertaining the component data, and so on. I think this would have been exciting considering from what I have read; Mr Honda's direction was "make it happen". Nice open cheque book, but well worth it. His GW legacy is alive and well.

Next on the Tuning tab is AFR/O2, user defined. Sensor types are Narrow Band (NBO2) or Wide Band (WBO2). The difference between the two has been discussed in other posts.

Once chosen, you choose the Algorithm, Simple or PID (Proportional Integral Derivative). Simple and PID a have the same initial settings, whereas PID has 3 extra settings.

Settings are:

No Correction: The O2 sensor is an indicator of AFR, but the ECU does not use the O2 sensor for any fuelling calculations.

Simple: The O2 sensor is being used without using the PID settings.

PID: The O2 sensor is being used with the PID settings.

When Simple or PID algorithms are enabled:

Ignition Events per Step: Number of tach pulse counts between EGO corrections to fuel. The ECU uses the O2 readings to adjust the fuel injection, but this is an after the fact correction.

Controller Authority +/-: Maximum percentage EGO correction can add or subtract from fuel calculation.

Only Correct Above AFR and Below AFR: settings to bracket when EGO correction will be active

Active Above Coolant temperature (°C): Minimum coolant temperature before EGO correction is active

Active Above RPM (rpm): Minimum RPM before O2 closed loop is active

Active Below TPS (%): TPS percentage where EGO correction is active

EGO Delay After Start (sec): minimum time required before EGO correction is active

The following settings are when the PID algorithm is chosen.

PID Proportional Gain (%), PID Integral (%), and PID Derivative (%) are generally calibrated through experimentation. This means I’m not too familiar with these settings.

Engine Protection Settings, to protect the engine from us the user.



Protection Cut: setting choices are Fuel Only, Spark Only or Both

Engine Protection RPM Min (RPM): RPM that Engine Protection and Limiters are not active

Cut Method: Full or Rolling. These settings determine how “hard” cuts are used. “Full” cut is where the ECU will stop all ignition events. “Rolling” cut is where the ECU will step through all ignition events, “1” ignition event per revolution.

Engine Protect, Rev Limiter, Boost Limit, Oil Pres Protect AFR Protect and Coolant Protect are user defined.

Reiterating what is found in TS and the Speeduino manual, but a good review.