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Tune FAQ! Work-in-progress...

PostPosted: Wed Jan 09, 2013 8:21 pm
by bigBADbenny
This guide was written, primarily from memory, based on everything I had ever read in my research on open source tuning of Subarus.
The keyword is open source, a community generated project for the benefit of all. If you can contribute anything to this guide please add your comments and of course CMIIW on any points, that is, correct me if I'm wrong. I'll strive to refine and add to the info here regardless.
Needless to say, attempting any of the procedures in this guide will be entirely at your own risk.

Please don't even consider modifying the engine of your Subaru without getting a tune first, and then getting that tune adjusted for subsequent modifications.
This applies especially to the exhaust, intake, turbo and fueling systems. Your Subaru is highly intolerant of mods without suitable tuning!
If you mod without a tune, your (especially turbo) car will run terribly and probably blow a piston ring land, rod or bearing, requiring an engine rebuild or replacement costing thousands of dollars.

The stock tune is optimized primarily for knock control and emissions mitigation, so even a stock car can benefit from a tune, especially as regards enhancing reliability, economy and performance. Some tuners are also expert in improving the response of the automatic gearbox, which even further reinforces the case for tuning a stock car.

Using a laptop pc and a Tactrix OBDII is the best method for keep tabs on your engine's health and paves the way for getting your car tuned. For day to day use I recommend the BtSsm app used with the BtSsm BT plug, Tactrix or VagCom plugs.
Bare minimum and better than nothing: elm327 and Torque app etc.

Preamble Part 2: (aka the conundrum of exquisite destruction, aka lets boil a frog)

Power is a dangerous thing in inexperienced hands.

The classic quote is: " the performance felt absolutely fantastic... :) and then it blew up :cry: ".

So you have your stock, tuned-for-emissions, car, with its tiny turbo and intercooler, all optimised for low end response, perhaps you upgrade the exhaust and maybe the inlet and it sounds more powerful, hopefully you got a tune too, but wow it's going great and you want more, it's just numbers, right? More boost more power! More power! It feels amazing, more boost!!! Right? WOOT! I'm an unashamed POWER addict!!! YEAH!!

No. It's just going to feel great then blow up. It will be a failed head gasket, broken ringland, cracked cylinder liner, lifted head spun bearing, bent rod or blown turbo, but it will be gone. Why?

Firstly: due to a lack of any enhanced support and disregarding the limits of the stock components.
A car is basically a support system for a series of controlled explosions, air fire, fuel and spark must all work in harmony to provide motive power.
If balance is not maintained, failure will ensue.

Secondly: Because the ej255 (and to a degree the other garden variety turbo EJ's etc.) was developed for extra torque at stock power levels only. Aspects of its design for that purpose mean inherent compromises to factors that relate to high power builds. Rod ratio, oiling and cylinder strength being the primary candidates.
A fairly weak serial delivery fuel line system being the other.
Uel headers on the postFL being another. Put them all together, it's intolerant to running on the edge.

Thirdly: stock tune optimised for emissions first. You want a drive-ability/reliability tune.

What the heck am I even talking about?
Well here it is in an edited quote from one of our most experienced members, Mick aka dr20t:
dr20t wrote:My strong advice to anyone chasing over 200kw atw from an EJ series motor is to ensure its tuned on a dyno, with knock ears. This is even more important on stock pistons running 98 Ron fuel. E85 I would be more concerned about cylinder pressure and dynamic compression ratio which can only be tested on a dyno as you can push well past MBT on e85 without knowing it until you get reversion or diminishing piston speed / torque. And that can only be properly done on a dyno.

In my opinion you can't blame a tuner for an under engineered engine from the get go. Whoever thinks the ej255 is a good platform for anything over 200kw atw is off their tree. The ej255 is an economy engine not a race engine.

Again it does come down to quality of parts and build quality but in this instance the fact is the ej255 is not conducive to sustainable high power. I know I've said in the past that they can be built to 230awkw reliably. But the more I learn the more I refine that backward. The ej255 is simply not built to tolerate high cylinder pressures for a long time in stock form.

Moral of the story - you pay to play. Bolt on mod choice is critical, as is engine history etc. Tune needs to be spot on and don't risk any bolt on mods without a tune.

Thanks Mick!
To sum up, if you want reliability over time, the EJ255 is not the engine to chase a dyno figure to brag about.
Its an engine that can shine, on the street, with supporting mods and a conservative tune.

Whilst this guide is not specific to the ej255 I thought the point was worth hammering home, and most of the issues covered do affect the 2 liters and certain generations of ej257s in varying degrees. Heads up!

So get a tune, support and build upon the stock system with the right mods and enjoy a more reliable, efficient and fun Subaru.
PS: Even more so if you have an auto and choose the right tuner.

Bad Noodle guide to tuning. ... ?t=1626520
Google this forum...

DIY Subaru Parts, Procedures, Diagnostics & FSM Info

Click the link to go to the DIY Subaru Parts, Procedures, Diagnostics & FSM Info page.

Get your Factory Service Manual (FSM) this is just one source: ... &hilit=Fsm

Consider whether you want a best-case scenario, or worst case scenario as regards the state of your car or something in between.
Regardless of what tune you are getting, the car will be driven harder than you might ever do in normality, thus:
Scheduled service. Meaning fully roadworthy in all aspects.
Fluids check.
Oilchange: considered sub 5K oil change intervals? Cant hurt really.

UEC (Upper engine Cleaner) method/procedure: ... ne.179036/

For NA:

Hoses check: most of the important ones are visible in the engine bay with the cover still on: no excuses.
The cover comes off very easily, so get it off and take a peek.
I went for a week or two till I spotted one. It was this one that had come off...
If you have a strong suspicion of loose hose/induction piping, there's:
For vacuum leaks e.g. inlet piping, google the "aerosol spray in the engine bay whilst idling" test.
See post 8 for the specific method: ... 26b#p67929
For positive pressure leaks a spray bottle of diluted dishwasher liquid is great for checking the BOV area, and the exhaust prior to it getting up to temp.
Failing that do a smoke tester check: info on the Google.
Good fuel from your trusted, regularly used outlet.

Learning View from Tactrix. Get a member to help if no Tactrix (yet) Software link below...

When to make an LV?
An LV made immediately after a reset has no Learned Values and is not very useful, unless you want to confirm your ECU was actually reset.

After 30 minutes of gentle driving after an ECU reset and any time thereafter.
After 30 minutes or so is a good time to begin logging and maybe make a pull, as the ECU should have learned in that time.

Via this thread: viewtopic.php?f=56&t=18219&p=375413#p375413

MAF clean: be gentle! Read the DIYs! Provide a recent phone pic of your clean MAF for your tuner (I did)
How to clean your MAF: unplug it, remove the 2 Phillips head screws and wiggle the MAF from the velocity stack (MAF tube). Examine the MAF: see the dirt caking one side of the visible IAT sensor and the MAF wires in the tube? Gently spray these areas with MAF cleaner aerosol or similar... Let it dry and reassemble in reverse order: do not touch the MAF sensor wires at all! Let the pressurized cleaner do the work gently dissolving and washing away the gunk :)

Is that air filter clean, sealed... triple sealed?
A handy list of your mods for your tuner... So you don't forget that geegaw you put in months ago...
Better still send your tuner a link to your Member Profile, then they can see how you present and describe yourself and your car and your aims and wishes for it.

Work out what mods require a tune immediately, and what mods don't.
E.g. (TBC...)
Induction piping: yes - may run leaner as airflow is smoother.
Zorst: minor changes e.g just muffs or mid - maybe not immediately/major changes eg dump pipe - probably.
Fuel pump - no (subject to debate)
Injectors - yes.
Fuel lines - yes.
FPR - yes
Intercooler - probably not immediately
Turbo -yes.
BOV - probably not immediately
3port boost solenoid (EBCS) - yes.

Research the popular mods for your vehicle, make a plan based on reality and stick to known equipment, installers, formulas that work.
Trailblazing is expensive and can be frustrating! Most of all have a plan!

Check Engine Light: CEL what do I do?
Symptoms: power and or boost limited, cruise light and engine light on dash are flashing.
The mechanical fault has put the car into limp home mode due to an error being logged by the ECU via its sensors.
Depending on what model Subaru you have the CEL can be read on the dash info display, or it can be read with a mechanics OBDII scanner, a Tactrix or a BT or Wifi OBDII plug and appropriate app, keep a record of the code, Google it and depending on the severity of the issue, reset the ECU or take appropriate mechanical action to fix the ECU as releveant to the issue.

ECU Reset Info:
ECU resetting how to basic mode: remove the battery negative terminal. Pump the brake pedal until the brake lights are extinguished, so eg if the handbrake is on: no brake light on the dash or tail lights.
ECU resetting how to advanced mode:: use an OBDII adapter and app, eg Torque App or Tactrix with Learning View or RomRaider. This is preferable because one can check for any stored diagnostic codes.

ECU resetting when to: whenever you have made a mod that will affect the learnt parameters in your tune.
Examples: changed panel filter type, changed to heavier oil, changed OCV soilenoids, cleaned filthy MAF.
Some cars require an ECU reset after flashing a tune, you can check this by taking a learning view after reflashing.
No learnt parameters equals a reset ECU.

ECU resetting when NOT to: When you have a CEL and no method to read the code. Usually if you have a severe-issue CEL, the car will stay in its limp home mode. Some less severe CELs will reset themselves after a period of time.
If you have a CEL, check it ASAP with an OBDII adapter of some description or find a member or mechanic who can.

After an ECU reset: drive the car gently, off boost, with a mix of traffic and freeway if possible. the the concensus seems to be that 20-30 minutes is enough time for the relearning to become established.

Common vehicle specific issues that, if not addressed, may affect the success of your tune:

AVCS issues a power and economy limiter...

3.0 engine rattle

Don't even start without:
Third party feedback from a trusted contact.
I just read this tip on another forum but I've been doing it since before getting tuned...
Now I have several trusted contacts who overlook goings on and help fill my knowledge gaps.

At minimum or for day to day use:
BtSsm allows monitoring, logging etc, but no ECUflash.
Here's my BtSsm setup.
Torque app via Android BT or iPhone Wifi OBDII adapter.
Monitor at least: boost in psi, AF1 afr, Ign tot timing, learned Ign timing.

Tactrix w/RomRaider, LearningView on PC.
AEM or LC-1 wideband.
Boost gauge
(VBG1 is apparently to be very accurate, especially on transient boost peaks)
No monitoring = no tune.

Read the full story here:
Warm the car up first...
A clean third gear pull please! WOT 2500rpm to the rev limiter, or 6500rpm (2.5T).
An airflow run: 15 minutes of mixed normal non-high boost driving city/freeway mix. No high boost OK?
The more concise your logs are, the less irrelevant crapola your tuner has to wade through.

Logging Parameters:
From Torqued Performance:
A/F Correction #1(%)
A/F Learning #1(%)
A/F Sensor #1(AFR)
Engine Load (g/rev)
Engine Speed
Feedback Knock Correction
Fine Learning Knock Correction
Ignition Total Timing
Injector Duty Cycle
Intake Air Temperature
Manifold Absolute Pressure (PSI)
Manifold Relative Pressure(corrected)(PSI)
Mass Airflow (g/s)
Mass Airflow Sensor Voltage
Throttle Opening Angle(%)
Vehicle Speed (mph)
Optional (but mandatory for health check):
VVT angles (L&R)

VVT specific parameters:
Engine Speed
Vehicle Speed (mph) (kph if not logging for a USA based tuner)
VVT angles (L&R)
OCV duty (L&R)
OCV current (L&R)

H6 tuning parameters from Xtreme Race Tuning: ... .php?t=501

The Pull: This is really important!

Please do your pulls on a dyno or private road, but if that option is not available:
Get on Google maps and find the very longest freeway ramp in your area and the next longest nearest that and so on.
When? When the traffic is quiet of course, if things don't look or feel right, back off and move to the next ramp or go round again, or pick another time.
You need to get this right since your terminal speed will be in impounded car territory if caught red-lined...
Use your common sense.
Turn off the freeway and enter the next ramp or cross the bridge, wait at the lights at the return entrance ramp and if there's no oncoming traffic entering, go for it.
Chances are you can do your pull to C130Kph and slow the car to the limit before merging with the traffic, if any.
It's important to have a clear road, in front and behind too, as an event like a WDC CEL can be a reasonably startling thing.
Better yet, do this on a freeway with a 110Kph limit.
Find that freeway on-ramp, use the defogger switch or F1 on your PC keyboard or better yet get a friend to assist you.
If the laptop is on a seat, use the seat belt to keep it in place for safety, better yet, use the floor.
Take it easy, keep your eyes on the road!
It's not a drag race, just a log, of your car, in third gear, accelerating, WOT. Remember that.
Don't worry if you forget to stop the log, it will be obvious where and when you changed up or lifted.
If you're super good just edit the unneeded cells in XL, OpenOffice or Pages.

Use status, request & feedback forms for email. Eg.
Status: where you are at, how is the tune feeling or performing.
Request: what is the requirement of the revision.
Recap: list of relevant mods to date.
Plans: pending mods that may require a revision.

Be concise, relevant, on point and brief!
Do not be all "should I, could I, I wanna, I'm gunna, I plan to, I wish???"... or the classic "my cousin's chicken shop burned down...!".

Carefully manage your communication with your tuner!
(the better the tuner, the more customers they will have)
Keep them informed of what you've done (mods and maintenance wise), what you want, what you are planning and what results you are experiencing as regards your tune, for better service.

Lastly be patient, it's in the tuners interest to provide a safe tune, they are on your side!
You are messing with the brain of your car, hopefully for the better.
You are making changes to a cybernetic interface, please give your car and yourself time to adjust to the changes being made.
Above all be aware!

Options for tunes:

Dyno plus road tuning: this is the most expensive and perhaps the best approach.
Preferably you'll choose a local tuner, but members have traveled interstate to get this done, with varying degrees of success.
Pros: Your tuner is also a mechanic, will check/fix/upgrade your cars mechanical state, do the tune in the controlled environment of the dyno, with further optimizations on the road, or vice versa. It doesn't need tweaking because everything is sorted, you're done modding for now and will concentrate on your aero etc.
Cons: You just spent tons on a second rate tune because the tuner is not that good despite what they told you.
You traveled miles for upgrades and tune only to discover a surprise issue that hinders your tune.
Dyno tuning:
Pros: See above
Cons: Less real world based results, so most tuners will offer the option of tweaking the tune on the road.

Road/E-tuning: can be affordable, once again best if local to tuner, usually less time available to check car for mechanical issues. Some tuners will provide revisions via logging/email.
Pros: You get to meet your tuner, they experience your car in person. You discuss your aims and make requests to suit your taste.
In this instance you might want to book some more of their time to firstly log the car with a view to sussing out any preexisting issues (see above) or take care of that comprehensively before getting tuned. You'll want to log both city and cruise driving.
After the tune is applied, take a little time to actually experience some normal driving to see if those DBW setting really suit you, and in all modes.
Get an LV & logs at the end of the session, at least to show your tuning mentor.
Cons: Since you don't need to have any experience or knowledge to do this, you are totally at the mercy of your tuner, at least until you get someone to overlook their work.
There is the chance (as with any tune) that they give you their tune, not the one you requested, and you accept their word that its what you wanted and asked for, because they know what they're doing, right? The tune turned out to be full of features you didn't want or need, that's if you knew about them in the first place.

Pros: Can be very affordable. International pool of tuning talent. You need to know what you are doing to engage.
Cons: Best for experienced owners with mechanically sorted cars. See cons above.
You'll need a full understanding of the required open source software, so you may need an experienced friend locally to help you out.

The key here is to not switch off the ignition at any time during the re-flash, or you will be getting your ECU unbricked, most likely by Chiptorque.
Switch off your lights, HU, HVAC and any accessories to conserve power.
If your battery goes flat during the procedure, leave everything in place, connect jumper leads or charger to your battery and proceed.
Make sure you have a known good ROM in your ROM folder. Bad ROMs can and do happen...

Again: do not switch off the ignition at any time during the re-flash.
Current ECU / ECM Unbricking / un bricking / un brick /un-bricking / un-brick / recovery / reflashing / service /services / unlock ecutek ecus and recover info / ecu tek
It happened to me, Chiptorque were great: customer service was simply impeccable...
I'm not sure how, but I managed to successfully test write a bad ROM, which failed to actually write, panic took hold of me and I guess I keyed off.
Total cost $220: Chiptorque reflash, $105: 2x 500g Platinum Express Post envelopes each insured to $2600...
Chiptorque reflash on Thursdays and Fridays, I sent the parcel containing the order form ECU and return envelope on Wednesday AM and received the unbricked ECU on Friday at 1PM.

Avoiding bricking your ECU:
Invest in:
A maintenance battery charger, have it attached to your battery during flashing.
Jaycar have a decent Cytec clone, or just get the real deal.
Since the car doesnt need to be running during flashing, this is the best way to keep your ECU and laptop powered up.
Its probably a good idea to disconnect once done though.

A dedicated ECU flashing laptop.
I'm preparing an eeePC for the job that runs from the 12V socket.
Since its just for flashing and logging, its a stripped back, optimized install with basic security and little connectivity.
Make sure the software and driver package is correct and without conflict.
Keep Java updated, the installed versions can be managed efficiently with Revouninstaller Free.

This is my XP current config, which is stable and works consistently. (thanks Bruce!) Updated 151114
These software versions...
Confirm what's best for your OS etc. here: ... ostcount=4

Learning View V1.0 RC3
RomRaider Latest Version, Defs etc...
RomRaider 0.5.6 RC6

Device manager view, note the Tactrix has an mSD card in the slot.

Please share the benefit of your experience for us all! :P
Thanks especially to my esteemed fellow forum members for your continued assistance!

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Wed Jan 09, 2013 9:19 pm
by XT_for_me
Thats a good write up Ben!

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Wed Jan 09, 2013 10:13 pm
by KiDo_Tuning
Also, it is best to try and use OLD engine oil. Changing the engine oil for fresh oil can impact the tune, as tuning for the 'best scenario' is not the goal... tuning for the WORST scenario(ie 10,000+Km old oil) is actually better.

Tighten hose clamps, boost leaks or vacuum leaks cause issues.

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Wed Jan 09, 2013 11:54 pm
by bigBADbenny
Cheers, I'm still adding stuff,some proofreading required! :D

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Fri Mar 15, 2013 9:44 pm
by bigBADbenny
With all the current discussion going on, please put your tips in here!

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Fri Mar 15, 2013 11:43 pm
by jakey

Thankyou in advance!

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Sat Mar 16, 2013 8:23 am
by jakey
Hi Ben,

Appreciate what you're doing.

On first glance, looks like a lot of your checklist is largely based around a turbo car - would it be possible to mention in the post whether certain checks apply for H6 or turbo cars? -

I realise some with a large ego might suggest 'Shouldn't that be obvious', but I have to learn somewhere and this thread is pointed @ n00bs after all.

Cheers mate.

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Sat Mar 16, 2013 8:26 am
by bigBADbenny
Waiting on input from H6 etc. owners as I'm no expert, but yeah afaik they have vacuum lines too 8)
There is a ton of discussion going on right now,so put your experience and opinion to good use!
If you have any input at all it would be most welcome, either post in the thread or PM me.

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Tue Mar 19, 2013 7:40 am
by SegR
Great thread Benny. I would suggest adding to the logging section that pulls should be at the advice of the tuner.

The H6 auto has funky gear ratios and reaches 140 in second. I've never hit redline in third. Maybe I'm just a pussythough.

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Tue Mar 19, 2013 10:03 am
by bigBADbenny
Ill add that: thanks!

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Fri Mar 22, 2013 8:31 pm
by Brunsy3.0
Subscribed, keeping an eye on this space

keep up the good work Benny

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Sat Mar 23, 2013 4:31 pm
by zch91
KiDo are coming to Darwin soon Brunsy. Incase you missed the thread.

/end KiDo related conversation (in this thread)

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Sat Mar 23, 2013 4:57 pm
by Brunsy3.0
cheers zach i think i did see that at some point, though really would like to finish my exhaust setup before i get a tune, is still a way off yet due to finance but am piecing is together slowly and then will be definately getting a tune done

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Fri Apr 12, 2013 2:23 pm
by fredhoon
Thanks for the noob checklist BigBADbenny!

My Tactrix & wideband have arrived and I'm slowly reading through the tuning guide from NASIOC. I'll be kicking off with some logging while learning up on everything prior to my timing belt service (and AVCS fixes if required), all in preperation for light bolt-ons and a tune.

Do you intend this to be a noob Q&A thread, or would you prefer questions have their own threads?

Re: The Pre-Tune Checklist for Tune n00bs! Work-in-progress.

PostPosted: Fri Apr 12, 2013 2:34 pm
by bigBADbenny
Great stuff!
Both I reckon: the guide needs better model specific info and some more detail in some sections...
I'm working on the wideband section "right now" lol.

As regards AVCS I need to do the solenoids DIY: it's really easy if you can twist a spanner/bend stuff.