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Tuning Evos on standard ECU

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Hey Andre,

I have heard that evos and sti's have this feature where you can actually tune and make changes through the factory ECU. Can you explain some more on how this is possible? Do you need to "hack" the ECU or anything of the sort?

Also, I have been told that evos use a MAF sensor from the factory, can you tell me if there is any difference in tuning a system like this vs what you have taught in the courses for millisecond, VE and TPS based systems?

My buddy has an evo x (10) and I might want to have a go at doing some tuning on it in the future, from your experience (if you have any) on the 10, is there anything in particular I should look out for ?



Hey mate,

If Andre cannot answer some of the stuff here, this is basically my bread and butter work.

I'll let Andre answer first, then fill in any blanks if you like.



Ben I really appreciate that, I'd love to learn more on this topic.

Tuning evo's and Impreza s can be done through the diagnostic port using a variety of software's, romraider, ecuedit, ecuflash etc or the premium software's such as Cobb, ecutek and the likes.

Each system has its own way of working so I'll not go into details of how to do each of them.

There's no massive difference in your tuning methods to how it's covered in the courses, if it's lean then you add more fuel, rich? Pull some out. The only difference is how the ECU measures the air going into the engine, some even run a VE table in their system as standard.

I don't personally have any experience with the X but I do know that torque delivery is key due to the autoboxs limitations, I know of a few people who've needed their boxes repaired on standard power

Hi, i have been doing a lot of reflash ecu "HACK ECU".

For evo, you need to purchase Tactrix Cable OpenPort 2.0 , download a ECUFlash and Datalogger software such as (Evoscan or Mitsulogger).

The cable is required in order to reflash the ecu "Hack ecu" to alter the fuel adjustment, ignition, rpm and etc. Its simple, if you follow the webinar, i think there was a reflash webinar. To get extra function to work on the ecu, you need to download the definition files. Without definition file, you can't edit the ECU files. The datalogger software were used to record any knocks, afr wideband and etc data needed to tune the files. I believe if you follow the courses Andre, im pretty sure this would be easy as slicing a cake.


Feel free to jump in and share your experiences BENchmark - This is a collaborative forum and I'm certainly not an expert in every field :) I have spent a bunch of time over the last 10 years reflashing late model Subaru, Mitsubishi, Ford and GM though so I'll share the basics here.

As has been mentioned already there are a variety of software packages that allow you to tune or reflash the stock ECU. You start by reading the rom file out of the ECU but this raw data is not overly useful by itself. What the software packages provide is an interface and a definition file that defines what maps are contained inside the rom file, how big they are, and what addresses they are located at. This gives us a graphical way of viewing and altering the maps much like we would expect to do in an aftermarket ECU. You can then make the necessary changes and flash them back into the ECU.

The software I most frequently use is the freely available ECU Flash package as well as EVO Scan. These require the commonly available Tactrix cable to connect to the OBD2 port. If you're looking at flashing EVO X or V11 STi, you will need the Openport 2.0 cable as both these platforms are CAN based.

So the upside of this software is that it's basically free with the exception of the outlay for the cable (I think evoscan is something like $25 USD). The downside is that since it's opensource, you are often somewhat on your own in terms of support - There is no manufacturer you can jump on the phone to or email if you have questions although there is a large forum based community to turn to. The ability of the software is also limited by the accuracy or completeness of the definition files. What I mean by this is that there may literally be thousands of maps inside the stock ECU. Some are obviously critical like fuel or ignition tables, however some maybe harder to work out and their interactions may not be so clear. This means that in some instances you might not have access to maps that you need to adjust or the outcome of a certain change may not be what you expect to see. The ecu flash community for a large part is based in the US so I find that USDM definitions are often pretty accurate and complete. JDM (what I mainly deal with) are often a little less so. Support for brand new vehicles is also a little slow.

There are also hacks or 'patches' to the many of the factory rom files that essentially rewrite the stock code to provide added functionality such as flat shifting, multiple maps, flex fuel, speed density or just about anything someone smart enough can think up :)

The other route you can take is to use a professional level package such as Cobb or EcuTek for example. These achieve much the same result but have the fire power of a large manufacturer behind them. This usually means proper documentation and proper definitions that are accurate - Even still, reverse engineering the stock ECU is a big job and often there are holes or a lack of understanding around certain features. Understandably if you go this route you will be paying accordingly and these packages can be quite expensive to initially purchase, plus you will have to pay a licence fee for each car you tune.

The actual tuning is not vastly different to a standalone ECU with the exception that you can't tune live. The way the changes are made is a little different but the principles are the same. We are planning to release some reflash specific course material some time this year.


Thank you very much for that in depth explanation. I have a better idea now of what it requires.

You mentioned something about USDM vs JDM vehicles. The majority of STI's and Evos here in Trinidad are JDM imports. Does this mean the USDM definitions will be different and hence wont work on the JDM car?

Benchmark, I'd like to hear your input as well.



There are usually three main markets covered in the definitions, EDM, JDM and USDM. All of them are in the definition packs that you can download from the software developers of the open source tuners, I'm not sure how ECUTEK and Cobb etc do theirs as they're systems that I don't have any experience with.

the best thing to get you started is go on the romraider, ECUflash forums, download the software and a couple base maps and familiarise yourself at zero cost, once your ready purchase the Tactrix cable and practise on a working engine.

The ROM files are different between different markets, and even within a single market there are variations. If you're using ecu flash or rom raider then you need the correct definition file for your particular ROM id. I mainly dealt with JDM and EDM models and I'd say that the base definition pack included with the likes of rom raider or ecu flash are probably about 90% accurate.

Ecutek works in much the same way but you don't have to go hunting for definition files as they are all included with the software package and in my experience so far (admittedly limited to the FRS/BRZ) is that they are quite complete and accurate.


Seems like it may be worth investing int he ecutek software and have the correct thing from the get go.

Do you need to tell them which market your car is from or does it come with all the different definitions regardless?

Also, when you purchase this from them, are you able to then use it on multiple EVO X's for instance?

It's a personal preference that depends a lot on what level of support you think you're going to be most comfortable with. If you are technically inclined then opensource is a cheap solution. If on the other hand you want a 100% proven solution then something like ecutek is probably smarter. Just be aware that the ecutek package is not a cheap investment.

If you purchase the ecutek package for an EVO X for example, this will have definitions for each of the EVO X ecus. You pay a one off licence fee for each ECU that you flash. Once you've licensed the ECU the first time then you can tune that ECU as many times as you like.

ECUtek unfortunately can't hold a candle to OpenSource in the Evo market IMO and has always been behind the times.

Perhaps I am biased as I have just developed my own ROM's etc with Speed Density, Flexfuel etc. and its just seamless like it was released from factory. Saying that, my market is all JDM based cars, which have had alot less native surpport compared to the USDM counterparts, alot of early teething issues, that I basically had to nut through myself and sort out.

For SST equipped Evo 10's, ECUtek has major issues holding torque in the gearboxes, as their gearbox programming tables either don't seem to work or are incorrect. I have fixed quite a few slipping boxes by converting back to OpenSource and tuning from there.

If I was going to support it heavily to the end user, then yes, you need to know the packages, platform and software back to front.

This is less of an issue on 10's than earlier models are the XML's are much better designed and all follow a similar layout which helps people jumping into the scene.

Ben how can I contact you further to learn some more on this?

Interesting feedback on the ecutek package @BENchmark. I don't disagree with the developments in the EVO community trumping ecutek in terms of advanced features. I wasn't aware of the SST torque issues in the EVO X.

My personal experience on the ecutek platform is essentially limited to the 86 platform right now where they are a pretty solid option. Ultimately just like in the opensource community someone still has to define the maps in the rom so there is always room for human error. One advantage I've seen ecutek provide is bringing support for a new platform to market quickly. For example with the 86/FRS, initially ecutek was the only reflash option. Of course their initial release was not perfect either and took a while to get to where it is now.

I've got no horse in the race though and have no affiliation to ecutek. My point about technical ability I believe is valid - If you're technically inclined, happy to trawl forums for hours to answer questions and have a good understanding of the reflash process then opensource presents a cheap and flexible option. If you are less technical and really want manufacturer support then a product like ecutek may be better suited.

Hey there, I've tuned well over 100 EVO's to date and I am still learning stuff, stock ECU has lots of hidden areas! I use ECUFlash and Live Tuning/EvoScan. I recommend for the EVO X you reach out to Tephra and get the V2 ROM.

Here is the link to contact him.


For the past 5 years I have tuned/checked several evos using Ecuflash and Evoscan. I have the two cables needed (1.3U and 2.0 models) to flash and read the ECU. I have never touched a Evo 10 - so no experience on it. Except that the SST box is a pain.

Few months ago I updated my evos ECU to a Link G4+ and the reason for this was motorsport use. The stock ECU (or swapped ECU on the evo 4-6 models) will handle decent power and the tuning is quite simple. BUT when you start to have race or semirace/track setup for your car - get an aftermarket ECU. The stock ECU works great on a road car or a car that you do spirited driving or enter a trackday. But when you go all out with a big turbo on a stroked engine - the problems start. Well depends how much time you want to spend.


Engine spec: 2.2l stroker, 272 cams, ported head, custom exhaust manifold, big turbo, inletmanifold changed, bigger injectors, R85 (ethanol) fuel

Using stock evo ECU to get reasonable idle - adjusting several tables (IF you know where they are and you have proper defination XMLs). Fuel, ign, idle valve (4 tables total). For Ecuflash you have to shutdown the engine each time you make a change.. each time.. So getting your idle reasonable - it takes several starts to make it right and time.. alot of time. Of course you can use Live tuning (a third program to have) and adjust certain areas from the ROM in the ECU. But as BENchmark said - you need to know it back to back. So a beginner could struggle with it a while.

Using link pnp to get reasonable idle - adjust fuel, ign, idle valve and ign idle feature. This takes from a beginner that never user the ecu/software 30mins to get the car running nice 1000rpm idle. And everything is adjusted "on the go".

For me the time used on troubleshooting or trying to find the right opensource forum to get the right XMLs so you can get a 80-90% defination coverage is taken out from my family/spare time.

I don't mean to say stock ecu's are bad - not at all. They are hobbyist friendly and you can achieve alot of power with the ECU. It's just the small things that start to pile up and I reached my limit with them.

As for Tephra - My opinion is that you should go Tephra always. Nice features and well searched XML definations. Also will get somekind of support in EvolutionM forum and MLR forum. Also in Geekmapped forums you can find helpful tips and tricks.

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