EcuFlash & Tuning Information
Updated 12/03/15
We have finished editing version 1 of the BHM Tuning Handbook. This has compiled all of the information within this topic, as well as other resources into one "booklet" for easier reference. This was put together as best we could right now to get beginners familiar with the tuning process and everything that it involves. Hopefully this becomes a great resource here for the rest of you.
http://blackheartmotors.weebly.com/tech.html
This article was originally written by nj1266 on the EvoM forums, it has had some editing done to it in regards to MIVEC tables/tuning that we do not use on the Galant platform, as of yet. All of the principles of tuning are covered in this topic, thoroughly. If you have questions ask in this topic, don’t be intimidated by the amount of content as this is a lot to take in at one sitting. Add this to your favorites as this is probably the most extensive and beneficial tuning information out there.
Disclaimer: Though this tutorial has covered as much information as possible for tuning with EcuFlash, you assume all risk and responsibility. Take your time and make sure you fully understand what each section is discussing before you start to make any adjustments. If you are concerned about voided warranty or damage to your car, leave this to a qualified tuner or do not modify the vehicle for warranty purposes.
Aside from the equipment and approach, the two most important elements to have are PASSION and TIME. If you want to learn how to tune simply to make money out of tuning, then you will suck at it. Passion should come first and making money out of tuning is a distant second. If you do not enjoy tuning, then do not do it. You will end up very frustrated and possibly damage your vehicle or somebody else’s.
When you first start reading you will be confused. The learning curve is steep and the task seems daunting. But do NOT give up, persevere. You CAN do it. It is NOT hard to tune your own vehicle. It is not black magic or rocket science. Some pro-tuners want you to think it is, so you will not do it on your own. I was in your shoes once. I thought that tuning was some voodoo/rocket science affair. I too trusted a pro-tuner, only to discover that the pro-tuner I trusted had serious shortcomings. So I took a vow to learn how to do this and never to go to a pro-tuner again. If you have PASSION and TIME, then the next step is to get the best possible equipment that you can afford. So what will you need?
Hardware Needed
1. Laptop: You must have a laptop. Modern tuning is all about computers. W/O a laptop, it is very hard to tune accurately with consistent repetitive results. There are many cheap used laptops on ebay. Make sure that you get one that is powerful enough for your tuning needs. I also recommend that you get a small laptop with a small screen. Mine is bulky and has a 14.xx inch screen.
2. Logging hardware: You will need a logging/flashing hardware cable. The one that all of us currently use is the Tactrix Cable (http://www.tactrix.com)..
3. Wideband O2 meter (WBO2): Do not attempt to tune your vehicle if you do not have a WBO2 meter. Do not use the narrowband O2 sensor on the vehicle to tune the car. The NBO2 was not intended for tuning purposes. It is used for emissions and it is only accurate under stoichometeric conditions and even then it is barely accurate. Tuning with a NBO2 was used back in the DSM days when WBO2 were very expensive and no one could afford them. Today, you can get a WBO2 meter for as little as $180. I use Innovate products. I have an LM-1/LM-A2 with two XD-1 gauges. One gauge reads AFR and the other gauge reads boost. The cost was $750. It was worth every penny. I have had zero problems with this kit.
4. Logging Software: The most widely used logging software is Evoscan (http://www.limitless.co.nz/EvoScan). It uses the tactrix cable to log data from your ECU port. It also allows you to integrate data from your WBO2 with the data from your ECU port. It costs $25. It is a one time fee that entitles you to later updates of the software. It is very user friendly and easy to set-up. If you want free software, then try Mitsulogger from the aktivematrix web site.
5. Tuning Software: The tuning software is known as Ecuflash. It is for free and you can download it from http://www.openecu.org. Be aware that some recent versions of the software have bugs in them and might not work on your lap top. I am still using version 1.29a because I do not want to deal with the possible bugs in later versions.
So now that you have all the equipment and tools, what do you do next?
First, you must install the WBO2 properly on your Vehicle. DO NOT install the WBO2 sensor behind the Catalytic Converter. That will give you erroneous AFR readings. The best position to place the sensor is in the down pipe 2 inches before the flange in the three o’clock position on the passenger side. Do not place the sensor in any position below three o’clock. You do not want condensation to form on the sensor and destroy the sensor.
Second, you have to go out and log data from your Vehicle. You must log, log, and log some more. Since I live in an urban area, flat freeway on ramp work great for me. Log in 3rd gear. Do WOT runs from 2500-3000 rpm all the way to red line/rev limit. Only log the essential data with Evoscan. Logging all the data from your ECU will slow your logger down. The essentials include: AFR, timing, 2 byte load or loadcalc, TPS, RPM, Knock, boost (if possible), coolant temp, IAT, injector pulse width, and injector duty cycle. You must study and understand what the data means.
Third, download the rom image from your ECU using the tactrix cable and Ecuflash. Save the image to your lap top. Make sure the you write the immobilizer code in your rom on a piece of paper and save it. Understand what the tables in the rom mean. Do not touch them or modify them until you understand what they mean.
Fourth, now that you have read a whole ton and logged your Vehicle, you can proceed to modify the tables in your rom. The most important advice I could give you is to work INCREMENTALLY. Make small changes to the tables. For example, in the high octane fuel table lean out the map by making changes of no more than 0.3-0.4 target AFR. Do not go too aggressive in your changes. Another important piece of advice is to make the changes SMOOTH between cells. Recently, I saw a map that had the target AFR jump from 10.9, to 9.4 in two adjacent cells in the fuel map. This same map had a timing jump from 9* to 13* from 6500 to 7000 rpm. . The lack of smoothness in the map transition will more than likely trigger knock. A 4* jump from one load cell to the next will more than likely trigger knock on 91 octane gas.
So which part of the rom do I start tweaking first?
A. Timing
Generally, speaking a stock rom tend to have a lot of timing advance. Timing advance refers to the degrees that the spark plug is fired prior to the piston reaching Top Dead Center (BTDC). The higher the timing number in the load cell that the car hits during WOT operation, the further ahead of TDC that the spark plug is fired. This is known as advanced timing. The lower the timing number in the load cell during WOT, the closer to TDC that the spark plug is fired. For example, say load cells 220-260 @ 3500 rpm you will see 3, 3 and 2. These numbers tell us that the spark plug will fire between 3-2* BTDC. As the rpm increases so does the timing advance. Why? Well the engine has faster speeds and the spark plug must be fired earlier or else there would not be enough time to complete the burn of the air/fuel mixture.
My approach to timing is to follow the MTBT method, i.e., Minimum Timing for Best Torque. Simply stated, the method declares that a tuner should advance timing until advancing the timing no longer yields gain in power/torque or, lacking a dyno, until knock is encountered. So my first approach when tuning is to eliminate the knock. This means that you must retard the timing numbers (read fire the spark closer to TDC) in the high octane ignition map(s) especially in the higher rpms. The AFR for this timing is 12-13 during spool-up, 11.6-11.7 during peak and gradually tapering to 11 by redline. It goes without saying, that if you run less boost, and a richer AFR then you can run more timing.
The method outlined above to setting the timing ONLY applies to 91-93 octane gasoline. If you are using E85 advancing the timing until knock is encountered will yield poor or catastrophic results. You can go past MBT on E85 and not encounter knock. You might end up damaging your engine.
B. Setting Boost (if tuning N/A Setup skip this step)
The majority of forced induction owners use an MBC to control boost. So this is what I will use in this write-up. The most widely used MBCs is the Dejon Tool (DT). It is simple to use, cheap, and effective. Turn the knob counterclockwise and the boost decreases. Turn the knob clockwise and the boost increases. Be very careful though, the DT is very sensitive to even the smallest of adjustments. So make your adjustments about 1/8 of a turn whenever you are increasing the boost.
So I installed my MBC, how do I set my boost?
Please refrain from using the “eyeball-the-gauge” method to set your boost. Mechanical boost gauges are inaccurate to begin with. I had a Defi D boost gauge that I thought was very accurate. When I logged the boost, the Def D was 1-1.5 psi off. I have logged several Vehicles that have had their boost set using the “eyeball-the-gauge” method and the result of the log is different than from what the Evo owner told me the boost was set to.
Logging the boost requires installing a MAP sensor and calibrating it properly based on atmospheric conditions in your area. A MAP sensor is usually tapped into the little hose that connects from the intake manifold to the FPR. That is the way it reads pressure. The pressure pulses are translated in the sensor into 0-5 volts signals and sent to a data logger. The data logger takes the signals and based on the calibration data that you supplied translates the voltage into psi.
I use two methods to log boost. The first uses the GM 3 Bar MAP sensor. This sensor is widely available and very easy to set up and use. I bought mine with a pig tail harness for $75. I set it up using the calibration data that was provided by the manufacturer. The calibration data that I enter in my logger (Logworks logs the LM-1/LMA2) is as follows:
PSI---------Volt
-14.7-------0
-8.9--------0.631
-4.4--------1.134
0-----------1.6
20.1-------3.884
29.4-------4.914
What about the boost limit, aka, boost cut?
What does it mean? If your vehicle hits a load higher than 255 (approximately 22 psi) for 1 second, then the boost cut will kick in. The higher the rpm goes, the lower the limit. So at 7000 rpm if your vehicle hits loads of more than 235 for 1 seocnd, then the boost cut will kick in. This is an excellent safety. Under no circumstances should you eliminate this safety feature on 91 octane pump gas. When it comes to boost limit, just set the limit slightly higher and please leave the boost delay alone. Setting the boost limit @ 300 or maxing it out to 319 simply removes the safety from your ECU in case of an overboost condition.
C. Tuning the Air Fuel Ratio (AFR)
AFR refers to how many parts of air are mixed with how many parts of fuel. So an 11:1 AFR means that 11 parts of air are being mixed with 1 part of fuel to create the air/fuel mixture. When your vehicle is at idle or when at cruising speeds your AFR is around 14.5-14.7:1. This is known as stoichometric or stoich for short. It has been found that the 14.7:1 mixture produces the least amount of emissions. And since cars spend 90% of their time at idle/cruise then that is the number that the manufacturers use to reduce the emissions on their car. It is worth noting that the 14.7:1 AFR does not produce the best gas mileage. The best gas mileage is produced are 15.2:1 AFR.
What AFR produces the best power for gasoline? Gasoline gives the best power when it burns at an AFR of 12.5:1. This is regardless of whether the car is normally aspirated, turbocharged, or supercharged. Some modern turbocharged engines with direct fuel injection can run that lean during WOT operation. The turbocharged Ecotec in the Solstice GXP is such an engine. That engine can boost up to 18 psi, yet it runs at 14:1 AFR at 3500 rpm and tapers down the AFR to 12.5:1 by redline. So can I run my vehicle at 12.5:1 AFR? NO you cannot and should not. The engine does not have direct fuel injection, and the combustion chamber is not designed to handle such a lean AFR. Furthermore, the car is running on 91 octane gas. Under high boost and lean conditions, 91 octane gasoline becomes very unstable and can self ignite causing knock and other assorted problems.
So why tune the AFR last?
Increasing the boost will also impact your AFR. Why? The higher the boost the higher the load cell that the car will hit in the fuel map. Mitsubishi designed the fuel map to become richer the higher the load cells. So when you up the boost you will hit those higher load cells and the car will run richer. If you tuned your AFR before your boost, then you will have to do it again after you increase the boost. Why do things twice? It is very important to note that the numbers in the load cells of the fuel map are NOT actual AFR numbers that you will log with a WBO2. Under no condition should you enter the AFR that you logged with your wideband into the fuel map. They are just numbers. The higher the number, the leaner the AFR, and the lower the number the richer the AFR.
Setting your AFR depends to a large extent on the boost and timing that your car is running. When running the boost and timing mentioned in this essay, I generally set the AFR at 12.5-12 during spool up, 11.7-11.5 during peak boost, and then slowly taper the AFR until it hits 11-10.9:1 by redline/cutoff.
So how do I go about editing the fuel map?
The formula to adjusting the fuel map is very simple. The Actual AFR (AAFR) is 11.13:1. The fuel map AFR (MAFR) shows a 9.7 number in the 5500 rpm and 220 load cell. Let us assume that we want a desired AFR (DAFR) of 11.4:1 in that load cell. What should the new map AFR (NMAFR) be?
NMAFR=DAFR X MAFR / AAFR
NMAFR=11.4 X 9.7 / 11.13 = 9.9353
So the number that you should enter in the fuel map in the 220 load cell @ 5500 rpm should be 9.9.
To make this easy on yourself, simply create a template in excel with the above formula and use it over and over again. This way you will not have to do any manual calculation. Just plug in the numbers and excel will take care of it. That is what I did and it works like a charm. This method takes the guessing out of AFR tuning and allows you create a very flat and consistent AFR.
D. Reading your knock sensor
An ideal combustion process behaves in the following manner:
1. The air fuel mixture is brought into the combustion chamber. Ideally this mixture should have around 12.5:1 AFR to extract maximum power from gasoline. Given that the Evo engine is about 17 years old, crappy CA gas, and high boost, this ideal is pretty hard to achieve w/o running water or methanol injection. As stated before most amateur tuners that I know run between 11.5-11:1 AFR on an Evo. That is a perfect recipe for detonation when you factor in the advanced timing that the car runs from the factory.
2. The intake and exhaust valves close and the spark plug fires. Leaner AFRs burn faster up to 12.5:1. Beyond that they burn slower. A faster burning mixture does not require as much timing advance as a slower burning one. What I am saying that it has the potential to run leaner AFRs and consequently less timing advance.
3. After the spark is fired the burning of the mixture proceeds. It begins at the spark plug and progresses in an orderly fashion across the combustion chamber. It is as if you took a pebble and threw it in a pond and watched the ripples progress outward from where the pebble fell. The burn should be complete with no remaining air-fuel mixture by the end of the combustion process.
In reality combustion sometimes does not progress in an orderly and smooth fashion. Sometimes the air-fuel mixture spontaneously combusts after the spark plug is fired but before the flame front reaches the mixture. This is commonly known as detonation or more commonly knock. Why does that happen? Too much pressure and too much heat combined with the lack of enough octane in the mixture to resist self-combustion. Think of octane as the ability of gasoline to resist self-combustion under pressure and heat. The higher the octane the less likely the gasoline will self-combust under high boost and heat that the Evo is known to generate.
When a car knocks, it causes a very sharp pressure spike that is outside the normal shape of a pressure curve during normal combustion. The pressure spike creates a force in the combustion chamber. The structure of the engine pings/rings in reaction to the force generated from the pressure spike. That is where the knock sensor steps in.
The knock sensor is usually connected to the back of the engine block. It is nothing more than a microphone. It reads the noise in Hertz and transmits it to the Evo ECU. The Evo ECU filters that noise using 12 different tables in the rom and decides if the noise is knock. If it is, the ECU sends a signal to the sensors to pull the timing in order to save the engine from further detonation and possibly damage. The knock sensing system is reactive and not pro-active. The timing pull happens after knock is detected and pulls timing to prevent further damage. It does not prevent knock, it tries to limit it after it has happened.
The signal that the ECU spits out is commonly known as “knock sum.” The loggers that we use have the ability to log knock sum. Generally speaking the higher the knock sum the more timing will get pulled, the lower the knock sum the less timing will get pulled. More on that later.
So what sort of damage does knock cause?
If left unchecked, knock can break the spark plugs, the valves, and the rings around the pistons. Second, knock can be very abrasive to the crown of the piston. Pistons on an engine that is suffering from excessive knock will look like as if it has been sandblasted with small pits in the top of the piston. Finally, excessive knock will cause a premature failure of your rod bearings resulting in the very distinctive rod knock sound.
Having said the above about the dangers of knock do not be surprised to know that almost all cars knock. As long as the knock is occasional and moderate cars can run for thousands of miles with little to no problems. While detonation is not an optimum situation for engine operation, it does not guarantee engine failure.
So how should I deal with knock?
As I briefly mentioned earlier the ECU spits out a parameter known a “Knock Sum.” That parameter is one of the most important to log when tuning your vehicle. Evoscan tells us that this parameter can vary from 0 to 50. When tuning your vehicle it is advisable to tune timing, fuel, and boost w/o triggering more than 1-2 occasional counts of knock, three at the most. We know for a fact that 3 knock counts pull 1* of timing. I have also logged occasions when 1 knock count pulls 1* of timing.
I tune for 1 to 2 occasional and sporadic counts of knock, three at most. Anything above that is unacceptable. Here is my take on knock:
1. All cars knock on occasion. I have logged an Evo that knocked the first log and then gave me three knock free WOT runs. Generally speaking, the first WOT log that you do tends to be knock prone. You have to do at least three back-to-back logs to make sure that knock is consistent. I do not worry about an occasional log that has knock it. If the knock is transient and does not repeat, I usually ignore it.
2. Knock is a problem when it is consistent and repetitive, i.e., it happens every log and at the same point in the rpm range. That is the kind of knock to worry about and work hard to eliminate.
So my vehicle has more than 2 counts of knock and the knock is consistent and repetitive. What should I do to eliminate it?
We know from MTBT (minimum timing best torque) theory that we should advance the timing until we either stop making power or we see the onset of knock. In this case we clearly see the onset of knock. So what we have to do is pull 2-3* of timing to combat the knock in that rpm range.
E. Injector Scaling
Generally speaking, the stock injectors will give you adequate fuel flow. Once you get more modifications done such as forced induction, cams, or higher compression, then it is advisable to get bigger injectors. If you get a turbo, then definitely get bigger injectors. If you install bigger injectors, then you will have to scale them properly and use the correct injector voltage latency, otherwise your car will idle poorly and stall on occasion.
So how do you go about scaling your new injectors?
Scaling injectors is a PITA. It involves a lot of trial an error. It is not enough to simply put numbers in the rom tables and simply declare the injectors scaled. You must test and make sure that the scaling is accurate.
Here are the steps I follow when scaling injectors
1. Open Ecuflash and open your rom. Under fuel locate the Injector Scaling table and the Injector Battery Voltage Latency table. On a stock Evo they look like this:
http://i228.photobucket.com/albums/e...ctScaling1.jpg
The table on the left refers to the injector value that the ECU is using when making its fuel supply calculations. The number in the table is always smaller than the actual size of the injectors on the engine. For example, the stock injector size is 560, but the number in the table is 513. As a general rule of thumb, enter a number in the table that is 15-20% less than the size of the injectors installed. For example, let us say that you are using 680 size injectors. Then you enter in the injector scaling table a number between 578 and 544. Please note that this is only the starting point and not the end point of injector scaling. The final number will be determined through multiple sessions of logging and testing your fuel trims. More on this later.
The table to the right is the injector battery voltage latency table, aka, dead time table. The numbers in the right column are in milliseconds. The numbers refer to the amount of time that the injectors take to open completely and produce maximum flow. The numbers in the left column are in volts. As battery voltage decreases, the time between the injector receiving the signal to open and when it actually opens increases. Therefore, you must send the signal sooner to have the injector open at the appropriate time. The larger the injectors, the more time is needed for them to open. So you will have to increase the numbers in the millisecond column to compensate for larger injectors. The trick is to find the accurate numbers.
Am I done now? Hell no. Now comes the hard part.
You need to make sure that the numbers that you have entered are working properly. To do that you MUST log your fuel trims for an extended period of time. The trims to log are:
LTFT Low = Long Term Fuel Trim Low
LTFT Mid = Long Term Fuel Trim Mid.
Both of these trims fluctuate between +/- 12.5%. The LTFT Low is for idle and the LTFT Mid is for cruising. Your aim is to keep both trim to +/- 5% or less. If the fuel trims are too positive, then the ECU will add fuel and this will royally make your AFR too rich. If your fuel trims are too negative, then the ECU will remove fuel and this will make your AFR too lean.
How do I log my fuel trims?
Logging fuel trims takes a lot of time and you will waste a lot of gas to get your fuel trims as close to 0 as possible.
Let us start with the LTFT Mid. You must drive the car at a steady speed for at least 16 minutes. Why? The fuel trims cycle approximately every 4 minutes. You will need to have them cycle multiple times until they settle on a number in your log. 16 minutes will allow your trims to cycle 4 times. That will give them ample time to settle.
Let us take my example above. We had the scaling at 552 for the 680 injectors. And we cruised at a steady speed of 60 mph for 16 minutes. We found out that the trims went way negative and hit -10%. So we pulled over and incremented the injector scaling twice. The scaling went up from 552 to 572. We flashed the new numbers into the ECU. Then we went logging again for another 16 minutes.
We found out that the trims are still going negative but not as much as before. This time our trims hit -8%. We now know that we are on the right track. But we are nowhere near the +/-5% that we would like to hit. So we pulled over on the side of the freeway again. Incremented the injector scaling in the rom twice. This moved it from 572 to 597. We flashed the new scaling into the ECU and went for another 16 minute log.
The numbers in the log were very close to 0. The LTFT Mid registered around -3. We are almost there. So we pulled over on the side of the freeway and incremented the injector scaling one last time. The new scaling was 609. We flashed the scaling into the ECU and went for yet another 16 minute log. The logs showed a final fuel trim of -1.86. We have dialed the LTFT Mid to as close to zero as possible.
The next step was to log the LTFT Low. This is done by logging the car for 16 minutes at idle. We did that several times and found out that the LTFT Low stayed at the -1.66 level. This is a similar number to the one we achieved with the LTFT Mid trims.
We have finally dialed our fuel trims. Are we done done now? Not yet.
Now you MUST go back and adjust your AFR fuel map to fit the new injector scaling. You are basically going to have to re-tune your fuel map to fit the new injectors. Just follow the section about AFR adjustment in this write-up.
The whole process is very time and gas consuming and it can get very frustrating. But with time and patience, it can be done
