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FAQ

Is E-tunez tuning safe?

The short answer is yes. E-tuning does not affect critical safety parameters in the ECU such as braking, ABS, Steering response or the immobilizer systyem. The car will turn, brake,  engage ABS and "immobilize" the same as it always has, as those are separate modules and systems. If your car was equipped with traction control, again these add-on modules are unaltered physically/digitally and the reference software in the ECU is untouched by E-tunez as well.

Rather E-tuning looks at defined performance related tables in the ECU designed to increase efficiency and performance. These tables are primarily used for fueling, ignition advance and cam angles. Primarily E-tuning is a performance modification designed to make the engine operate more efficiently and flow better. This results in better performance and mileage.

Outside of the realm of performance tuning, there are safety parameters inherent in the ECU itself and in the tuning software. For example the ECU can not target leaner then a 14.7 Air Fuel Ratio which is the best ratio for emissions. Also the drive by wire throttle tables used in the ECU undergo error checking in the tuning software to ensure that throttle plate is closed when the throttle is lifted. Neither does E-tunez alter these values from factory maps, but in the event that you modify them yourself through your personal tuning software you have peace of mind knowing that safety components (error checking and zeroing on up throttle conditions) inside the software keep the car behaving as it should, even in the event of an error.

What vehicles are supported?

Currently the K series, R18, and F series engines are support from 2006 and up. The R18 is location specific, check with www.hondata.com to see if your R18 is supported. In the future the motor list will be expanded as results and feedback is gathered. The map you will recieve is up to you. The 8th Gen Si has two common tuning solutions, Cobb and Hondata. If you provide a datalog for a Cobb unit (.csv) and map (.ptm) you will get a Cobb custom tune. If you provide a Hondata datalog (.fpdl) and map (.fpcal) you will recieve a Hondata custom tune.

Should I E-tune or Dyno-tune?

An e-tune or a dyno-tune are BOTH better then running a basemap. For the average user, a quality e-tune is sufficient, but for an all out performance enthusiast the best answer is both. A user can run JUST a dyno-tune alone if a complete top to bottom dyno-tune is done properly. This will tune your completely part throttle and full throttle for the conditions present in the dynoshop at the time of the tune. Typically this involves 5 hours of data analysis (reviewing information) and 3 hours of related physical work (strapping the car, changing parameters, uploading, etc etc) for a total of an 8 hour day. This can get expensive when your paying $100-$150+ an hour for use of the dyno.

An e-tune will average the values out in real world conditions, taking the numbers from the datalogs you provide for the conditions AT the track. This means that the best answer to this question is to get both an e-tune and a dyno-tune. Why Both? For one reason you are going to get 2 opinions on how your car is running, which is better then one. For another you are going to save money getting the majority of the basic work out of the way before ending up at a $100-$150+ an hour dyno shop. And finally, an e-tune bases its feedback on the complex OBD-II systems in your car for real world conditions. Combine this with a good dyno shop which can further "fine" tune parameters such as ignition that are hard to gauge in a datalog the final dyno tune will complete the tuning process for a perfect running vehicle that is fully tuned.

However, something to remember is that the bottomline with all tuning, is that a tune is never complete, it is after all software, and when a good dea comes along you can always further improve it. The more time spent analysing your tune, and how the car is running, the better it will run. Its a law of averages, just because it runs perfect when its sunny and dry doesn't mean it will run the same when the barametric pressure falls and the humidity rises. Theres always another issue that can be found and better averaged out for ideal running conditions.

A naval acoustic engineer once said someting similar. No matter how quiet you make a submarine, there is always the next loudest noise. Even if the engines, propulsion shafts and sonar systems are silent, theres still people, footsteps, turbulence and electrical noise. The work is never done, its all a matter of how far you want to pursue it.

Tuning a combustion engine is very similar, it can always be improved given enough time to analyse the averages. The more detailed the datalog and the more revisions in place, the better then tune. The problem today is often a much smaller time frame of data is anlysed on a dyno leading to a poorer quality tune due to a very narrowband of analysis, this is epecially true if the user can only afford to analyse WOT values. Also this is because the data gathered while the car is both IN the shop and TURNING the dyno, rather then at the track in the weeks leading up the dyno. The user understandably doesn't want to spend 8 hours for a complete part throttle tune and often there there is not enough time to capture all the issues. The dyno tuner's hands can be tied if the user doesn't want to spend the money for the time on the dyno. The good news is with modern OBD-II systems 90% of the tuning can be done before hand, off the dyno. We recommend getting a quality E-tune, ensuring your tune is free of error and running as optimal as the OBD-II system can measure. Then if a dyno tune is desired, E-tuning will save you TIME and MONEY on the dyno as the majority of the tedious work is complete, and the tuner can focus on WOT. In the end ensures a better overall tune as all areas have been properly analysed and tuned.

A dyno-tuner will appreciate the fact that you car is READY to be tuned as well, the basic issues are out of the way, the car is running properly and performance areas like RPM indexing, engagement points, basic ignition and fueling values have already been sorted according to your goals. This means more time can be spent optimizing the car on the dyno and using that feedback rather then correcting unforeseen problems. In the end you will get more for your dollar, as the time at the dyno-shop will be used to fine tune, and gather feedback from otherwise unmeasurable parameters such as MBT (Minimal advance for Best Torque) which is an ignition value.

E-tunez can put you very close to the ideal parameters based on sensory feedback and experience. A dyno-tuner with other issues out of the way has a great iew of where to find those extra 2-3 degrees and finalize the WOT portion of tune, and they will be able to do it in less time if you come to the shop with a pre-tuned car. This saves you money.

What can E-tunez do for me?

Aside from a custom map, thorough datalog analysis, and the peace of mind from experienced personelle analysing your setup, you will get a complete report, and screen shots of what was done to your tune, and why it was done. You get the peace of mind of a job well done, and the proof behind it to back it up.

This is a sample report from an E-Tunez analysis of a users dyno-tune. The user complained that the fuel mileage had dropped significantly and the car seemed off, popping between shifts amongst other symptoms since his tune. The initial Revision 1 revealed many faults.

Saturday, February 13, 2010 - Tune started at 9:02 am

Tuner: E-TUNEZ.sp
User: ©©©©©©©©©
Datalog Analysed: ©©©©©©©©©.fpdl 6119k
Tune Analysed: ©©©©©©©©©.fpcal

Modification List:

Skunk2 Header
Skunk2 70mm Catback
AEM V2 Cold Air Intake
Acura Rdx 410cc Inj.
Spoon Venturi Throttle Body

Tune Target Request:
Performance (Safety margin’s included).

V1 Initial Notes: (Bold is Actioned)

  1. Improvement Noted for Low Cam Angles (see old values @ LowCam.PNG)
  2. VTEC Window Noted at 5000-5200 modifications support lower.
  3. Rev Limit Recover (Reduced to 8550 – safety margin).
  4. Warmup Ignition Retard Disabled.
  5. S02 disabled due to Race Header.
  6. Throttle Table smoothed, sensitivity adjusted for larger TB. (see old table @ ThrotTab.PNG)
  7. Cam Angle.Low Breakpoints Noted (4000-4200-4500-5000) unsure of reason, VTEC was set to 5000, and no increased resolution at transfer point?
  8. VTEC Window Adjusted to 4500-6000 (Can go lower if desired)
  9. VTEC Window Pressures Adjusted to 0.85 BAR
  10. Cam Angle.Low Breakpoints Adjusted to Match ETUNEZ tuning method
  11. Cam Angle.Low Part Throttle Significant Adjustment (fuel economy), but left WOT values as per dyno tune.
  12. Cam Angle.Low VTEC engagement ramped to 50 degrees (smoother engagement, no TQ dip at crossover)
  13. Cam Angle.High Significant Adjustment to both Peak values and Return to 0 values (safety margins)
  14. Ignition.Low Restored Default Part Throttle Hondata Ignition as PT values were erratic. (Retained WOT Values).
    (NOTED ALL LOW CAM IGNITION VALUES WERE THE SAME AT ANY CAM DEGREE??, Re-adjusted according to typical flow differences.)
  15. Ignition.High Partial Restore below -4.3 PSI due to errors, restored to default Hondata Ignition (Left WOT Values as they appeared ideal as per dyno-tune)
    ----------------- FUELING
  16. Initial Notes Suspect Tuning was Done Cold (LARGE Neg. STFTS when warm) (see STFT.PNG)
  17. VE Tables show DIP at 0-500 RPM, changed (these values used in starting conditions)
  18. Fueling at Low VTEC changed to Match Fueling at High VTEC Engagement (Previously fueling dropped at engagement, see 42:24 and 43:26 in  ©©©©©©©©©.fpdl)
  19. Fueling is still not smooth in places, will need more logs to confirm, both WOT 3rd Low/Hi and part throttle Hi Vtec.

Tune Done @ 10:54am - Revision 1

Final Checks: (Bold is Actioned)

  1. Calibration Notes correct? - sp
  2. Injector Size correct? - sp
  3. Fuel Low High VE Tables correct? - sp
  4. Fuel Lambda -(Improvements can be made in Rev2, but no issue) - sp
  5. Ignition targets correct? - sp
  6. VTEC WIndows and Pressures correct? - sp
  7. Cam Angles Low&High correct? - sp
  8. Closed Loop (Noted STFT's were set to -15 + 10 maximums in dyno-tune, changed to -20 +20 due to STFT maxing out) - corrected - sp
  9. Knock Adjust correct? (Noted changes to index's and values) - sp
  10. Sensors calibrations correct? - sp
  11. Idle correct?  (noted was @ 850) - sp
  12. Throttle Table correct? - sp
  13. MISC settings correct? - Noted VSA was enabled, left enabled. - sp

Here are some before and after shots of this users tune, pay attention to the top DARK blue line which is the Short Term Fuel Trim, this is how hard the ECU has to work to correct for a bad tune, also pay attention to the top RED line on the two 3rd gear runs, this is the Air Fuel Ratio, the more stable it is, the better.

Before (WOT/Cruise):

 

After E-tunez Revision 1:

(Driving)

 

(WOT)

 

You can see from the above two screen shots much was improved after a few hours of data analysis and corrections. The user was very satisfied with the new tune. The best part was E-tunez kept the majority of the dyno-tune work so ensure the WOT performance was not lost in the re-tune, and concentrated on the errors in the tune and on part throttle improvement. This means this user does not require an additional WOT dyno tune, saving them money.

How does E-Tunez know how to tune my car without a dyno?

In the days of carbureted engines, tuning on a dyno was a necessity. A dyno graph was the only form of feedback, aside from the art of reading plugs, and listening to the tone of the exhaust.

Now adays, tuning a fuel injected vehicle has evolved from an art of the gear heads down to a science. It’s a battle of numbers, instead of a battle of sounds, colors and smells. For example we tune for 13.1 AFR, 54 psi of fuel pressure, and 27 degrees of WOT ignition advance as opposed to light brown spark plugs, a crisp exhaust note and no ping. The tuning process has evolved and we have learned that the result of good number’s, IS good colors (plugs), tones (exhaust) and no knock (ping) rather then vice versa.

There are many other forms of feedback available to the enthusiast. You have a large array of sensors that your vehicle uses to compensate for elevation changes, manufacturing variances, fuel condition, and driving habits, to name a few.

We can use these sensors combined with the FACTORY built-in Wide Band O2 sensor to tell how your car is running, and verify any changes made.

E-tuning your car will ensure that Short Term Fuel Trims (a measure of how close the car is running to “ideal”) are as near ideal or 0% as possible, it will confirm your AFR’s are within the target range (13.1 - 13.5 for the K20Z3), it will confirm that your map is free of errors (RPM indexing, VTEC fuel transitions) and it will tune your car FOR the way YOU drive it!

When you provide a datalog of your daily driving, we can see how the sensors are responding to your input, and your current location. When your car was produced, the manufacture did not know where it would be driven, who would be driving, and how you would be driving it. The manufacture did not know the quality of fuel you would use or the exact concentration of ethanol in that fuel. On top of that, every car of the same model and trim level leaving the factory had the SAME ECU mapping despite all of the above variables.

This left the difficult task of using one ECU mapping, for tens of thousand’s of different cars spread across the continent… IE the North American 8th Gen Civic Si. Honda didn’t know which part of map you would use every day, and they certainly did not take a car all over the globe to test in every real world scenario IE Colorado (elevated and dry), vs Miami (sea Level and Humid), vs Canadian Winters on the prairies... etc. All those factors affect the STFT or overall performance of the vehicle, and how long it will take to learn to correct itself.

When the STFT shows it is out (anything other then 0%), the car must “re-learn” how to get things right. This time that the car spends “re-learning” costs performance and mileage. When the fuel maps appear incorrect due to closed sensor production variance, location (air density, humidity), or modification, this re-learning will happen EVERY time you change the pedal position, or the vacuum in the manifold.

When we tune your car, we look at WHERE it is being used and HOW it is being used, and our tunes account for those conditions, along with conditions that were not accounted for at the factory, like sensor production variance… For example, not every Mass Air Pressure sensor is exactly the same, and the same can be said for every other sensor in the vehicle. When your car was brand new, it could typically run a +/-10% Short Term Fuel Trim… as you add modifications, un-tuned it will drift even further, unless your really lucky and happen to compensate in the other direction. Either way you won't know until its tuned and the numbers are analysed. Within the first 2 revisions we usually have the K20Z3 running within 5% of ideal, including all modifications… by revisions 3-5 we are typically within 1-3% of ideal, in all conditions measured. This results in a huge improvement in drivability, as seen in our feedback section. Just start and go... no bucking, or hesitation when cold... great performance from startup to shutdown, unlike a stock or similar baseline map.

How accurate is the factory WBO2 sensor?

The factory WBO2 is fairly accurate has measured by Hondata, and also as confirmed by E-tunez. Under certain conditions (extreme rich or temperature) the sensor can read off slightly, but in general is more then accurate enough.

At part throttle conditions the sensor excels, reading stochiometric AFR’s very accurately. At WOT conditions the sensor reads correctly as long as it is not overheated, or subjected to AFR’s that are too rich.

Here is an example of the stock WBO2 vs an aftermarket Innovate LC-1 WBO2:

WBO2 Compare

Overall the sensors are very close... but since tuning is an art of attention to details, lets take a look at the differences. The second run with a larger error range was done within 25 seconds of the first run (see times). As long as there is a minute between runs, the error gap remains small, like in the first run. We can also further judge these conditions if necessary by looking at how and when the datalog was done, the Hondata Flash Pro tuning solution accounts for this error and corrects Primary O2 sensor readings under necessary conditions.

What is the correct way to capture a datalog for E-tuning?

The first half of the answer is SAFELY.

For users that are only capturing specific variables in the datalogs be sure to capture the following:

1) AFR - Air Fuel Ratio
2) MAP - Mass Air Pressure
3) MAF - Mass Air Flow
4) RPM - Revs Per Minute
5) IPW - Injector Pulse Width
6) TP - Throttle Position
7) MPH - Speed
8) STFT - Short Term Fuel Trim
9) LTFT - Long Term Fuel Trim
10) IGN - Ignition Advance
11) CA - Cam Angle for the Intake Cam Advance

The second part of the answer is drive normally, use all the gears and all the conditions you might encounter in your daily drive. This will allow us to see WHERE the ECU is having to the most learning and where the AFR’s are incorrect, or timing or other related condition is causing knock.

If you are at the track or a race event, drive the same as you would as if you were not datalogging.

For AFM based tunes where MAF Cal is important, to ensure proper STFT and Grams/Second data, we suggest maintaining a constant speed of 35 MPH to start... and every 20 seconds, bump up the cruise control 3 times. Continue this until you reach 80 MPH, or the limit that the conditions impose on safety. This way the car gets sufficient time to datalog each level of vacuum for each grams / second reading. This is good for both style tunes, but is more important for AFM or MAF based tunes, and less important for SD or MAP based tunes.

This will allow us access to the information we need to adjust your tune according. We do ask for two WOT 3rd gear runs from 2000 RPM to Red Line. These should be done at the track under safe conditions. Above all drive safe and IF you choose to provide a datalog done in day to day driving conditions (we recommend logs done at the track), obey local traffic laws! A good tune can make your car perform better, burn less fuel, meaning fewer emissions, and lead to more reliable operation, which will reduce the overall cost of ownership… Our biggest reminder for datalogging is to drive safe and responsibly.

Why 3rd gear for WOT datalogs?

On many engines the K20Z3 included, the AFR will change with gear. This is a result of cylinder, and manifold temperatures as well as RPM delta. The RPM "rate of climb" or" change per second", changes with gear, but yet many other factors like ECU speed (cycles per Revolution) or closed loop operation do not change with gear. When closed loop is disabled at WOT the result of those factors is a degree of richness the taller the gear is. If we tune 4th gear for 13.5 AFR (borderline lean), we may easily find 3rd gear running 13.7 (lean) AFR and 2nd gear running 13.8-13.9 AFR (very lean).

3rd gear allows for safe speeds even at redline (in most setups), and provides a midway between 2nd and 4th gear WOT runs. 1st gear WOT lasts (2 seconds)… and 5th gear WOT is hardly ever seen, and even when it is, it will just run slightly richer (safer) then 4th gear. This makes 3rd gear the ideal choice for measuring fueling and knock values… unlike a dyno graph where the optimum gear for accuracy is the one that provides the closest ration of 1:1 of wheel speed vs Engine RPM. (IE 6000 RPM at the crank should equal 6000 RPM at the wheel).

Remember to allow at least 1 minute between WOT datalog runs. The more cooling time the better, lower gears are more forgiving for primary O2 sensor accuracy vs taller ones.

Here is a 2nd, 3rd and 4th gear run, looking at AFR’s: 

Second gear was tuned for 13.1 but yet by 4th the AFR reads 12.7ish on the LC-1 WB02 due to above described affect

Do you recommend installing a WBO2?

Absolutely, the more sensors and feedback, the better. The AEM UEGO is a good sensor as well as any of the MOTEC units, and because of its low price the LC-1 has seen a lot of use by enthusiasts worldwise. Many of the aftermarket O2 uses the same physical WBO2 sensor, but use a different controller to drive the sensor. As long as the sensor works out of the box, is installed properly and calibrated as per the manual the results can be trusted as good as its nearest competitor, especially since we have a factory WB02 to further verify the results.

Which Tune is right for me?

For the enthusiast desiring a tune that delivers the best possible performance, consistency and MPG, we recommend our ultimate tuning package. This tune carefully focuses attention systematically on every available area we can look at including all commonly used day to day values that most dyno shops do not look at. We ensure all areas of the ECU map have been tuned, averaged and are corrected to be running optimally. Due to the MAF architecture of the R18 ECU, R18 users get a great deal on the R18 Ultimate tune as well.
We are able to spend more time fine tuning and better averaging the provided datalogs to minimize ECU learning time, and maximize performance and response. We will provide revisions if necessary for every datalog within the first 30 days for even better service, with a minimum of 6 revisions included.
Even if you have a Forced Induction setup, you can add Forced Induction analysis to this tune and ensure that all necessary FI tables are properly analyzed. Because FI involves twice the tables, and twice the analysis, this is an especially get great value for your dollar if you are supercharged or turbocharged.
After a purchase, any enthusiast can come back at anytime for a re-tune request, and we will provide the same great service we originally provided at a great price and re-vamp the tune for new modifications, seasons, or location requirements.
Because a tune is never complete and is only as good as the time you spend on it, if you want to be sure your tune is perfect, after a quality E-tune, take it to the dyno shop for those last few degrees of optimization. Through the use of UltraVNC, you can take E-tunez along with you with our dyno package. Using Wi Fi or IPhone tethering we can access your ECU tables via Live Tuning if you have a laptop with Internet access. Arrangements will need to be made before hand with one of our tuners. Also... the dyno package gives 120 days of free re-tuning to cover you for the summer, even if you add or change existing modifications. A great deal that you won't find anywhere else!
No matter which tune you choose, if you choose to deal with E-tunez we will take care of you from start to finish and we guarantee your satisfaction. We will work with you until we have accomplished what we set out to do and our tuners are here for you if any support issues should arise.

I purchased a tuning package, now what?

Thanks for your business, we need a bit more information before we can start working on your map. We need:

1) Modification list

2) Vehicle year and mileage

3) Body type (style)

4) Tune Style Desired (Race/Performance)

5) Also we will need the approximate location and elevation of your daily driving to reduce the learning time for IAT's, elevation and vacuum table indexing as we will pay particular attention to those affected tables and may adjust vacuum table indexing to better suite your location.

6) If you have a custom map you are currently running please provide datalogs for that map as well as the map itself, as we will use this as a starting point, even if it requires significant revision. However, if you have no base map or datalogs it is not an issue and we will provide you with one to test as a base map and start datalogging at that point. We will also need to know the Fuel Type the logs were done on, the octane rating and ethanol content. Ethanol will affect the target AFR's. For example a minimal content ethanol fuel may perform best at a 0.90-0.92 Lambda (stock O2 reads13.2-13.5 WOT AFR), while a 25% ethanol fuel may perform better at a 0.86-0.88 Lambda (stock O2 reads 12.7-12.9 AFR). A E85 or E100 mixture may be targetted even richer, so knowing the fuel type is important.

7) Lastly if you provide a custom map, we need to know if your vehicle was dyno-tuned on that map (not just dynoed). The difference is instead of starting from scratch we may use your existing map as a starting point, or we may start from fresh but simply retain Wide Open throttle ignition or similar settings etc and transfer into a better tuned starting point for your modifications if something looks very amiss (part throttle fueling, cam angle indexing etc) in the dyno-tuned map.
COBB users, please ensure all datalogs are logging at least the following 11 variables:

1) AFR - Air Fuel Ratio (or A/F Sens 1 Ratio)***
2) MAP - Mass Air Pressure (or Boost PSI / Man. ABS. Pressure)
3) MAF - Mass Air Flow (or MAF (g/s) or AFM)
4) RPM - Revs Per Minute ***
5) IPW - Injector Pulse Width (or Inj. PW with Lat)
6) TP - Throttle Position
7) MPH - Speed (or Vehicle Speed)
8) STFT - Short Term Fuel Trim (or A/F Correction 1)***
9) LTFT - Long Term Fuel Trim (or A/F Learning 1)***
10) IGN - Ignition Timing Advance (or Ignition Timing in Deg)
11) CA - Cam Angle for the Intake Cam Advance (or AVCS in/out *both)
12) Knock - Knock sensor feedback (or Fine Knock Learn / or Knock Volume)
13)  Load - Vehicle load as a %. (or Calculated Load) ***
14) DAM - D.A.M multiplier for Subaru *If applicable / model year dependent.
*** = Tune Critical, can't tune without. We also need your Cobb AP Serial number, very important as ATR Pro requires this information.
ALL users, please email the above requested information list to tuning@e-tunez.com. after your order is complete.
Please remember during all tuning to use the same fuel type and ethanol content as this affects AFR and STFT. Try and keep the fuel level above half a tank during tuning, as some car tends to run sporatic fuel pressures when on the last few bars of fuel (this is why some cars report  harder starting when near empty). Also, please allow the car to warm up fully before making any datalogs for submission, at least 10 minutes.. Typically we request a 30 min driving datalog and 1 to 2 WOT 3rd gear datalogs for each revision. These can be combined into one datalog or separate. For part throttle tuning, as revisions continue we may request to increasse the datalog length for near completed tunes. This is due to the law of averages as in order for higher accurracy and averaging then previous revisions we need more information.
Also, we have several tuners available as found under Contact Us. If you have preference or were recommended here by one of those indivudals you can specify which you would like, otherwise one will be assigned a tuner whose experience best matches your modification setup.
In general, all maps provided by E-tunez will be provide VIA your E-tunez.com user account, when the map is complete a notification will be sent to email address you provided for your user account. Typically this is within 24 hours. You can log into your account at anytime to check. Also, we need the above information (modifications etc) before we can a map in the works for you as well.
Lastly, for your satisfaction we also offer you the option to upgrade your tune within the next 14 days, (even if your current tune is already completed). Instead of purchasing a new tune, if you have purchased a package and decide you  would have rather bought a different one, we offer the option to upgrade you to a different package (or set of extras) for just the difference of the original cost. Just email us and let us know.
If you have any questions or concerns or suggestions for improvement please let us know. We are here to support you before, during and most importantly, after your purchase.
Thank you for your business, we aim for your 100% satisfaction.
The E-tunez Tuning Team

How do revisions and revisions numbers work?

Revisions are what we do as a tune is updated. Every time an update is applied to a tuning map, the revision number increases by one. It is a way of keeping track of the changes and organizing the changes systematically. You may wonder what we mean by revision numbers in our tuning packages. The main point to understand is that they do not limit your tune, instead they are a minimum guarantee for your benefit.

Think of revisions like "free" re-tunes. At E-Tunez we know tuning is an ongoing process that is as good as the time you spent on it. This means tuning is not something that is ever finished 100%, the more time you spend on it the higher quality the tune becomes. Since we want to ensure you get the highest quality of tune we gauruntee to re-tune your vehicle until completed, and also use revisions to set a minimum number of tunes you will recieve. These revisions, are generally done back to back, one per day at least but the schedule is ultimately up to the user.
When we create you a map, we base it on the datalogs your provide us with, and as tuning is a law of averages the more datalogs we see the better "averaged" your tune will be. The revision number lets you know how many re-tunes in total you will receive at a minimum. If theres still a problem with your tune, we keep going, but the revisions are there to ensure a minimum, as well as better averaging.
This means your car will be running near perfect and well averaged for all conditions and not just WOT. Revisions is not something the industry is very receptive of. When you go to tune your car at a dyno shop, it may be running good that day, but what about the next? If the shop let you come back for re-tunes every time the weather changed the dyno equipment would be broken, long before the shop broke even on its investment. It is very crucial to understand that the portions of the map being used to regulated the car, change as the environment the car is being run in changes. 
This means for better averaging, we re-tune you car a number of time to make sure we got it right. While for a average tune we are very close to ideal in just a few revisions, some customers with custom work are running tunes with revisions in the 10-20 range just to make sure things are as near perfect as possible. We keeping tuning until complete, which is the point when environmental changes are having a larger affect then the updates we are making in a tune, (around 1-2% adjustments). Sometimes this can happen before we meet your minimum revisions, so that means you now have extra revisions to use at your convience.
Our Ultimate Tune as this is a great way to ensure the car is completely tuned, as we essentially will keep working on the tune as often as your provide datalogs. Some of the higher revision numbers tunes are a work of digital art, as the car will run near very close low STFT's in almost every condition, with flat line AFR's and smooth transitions for all fuel maps and cam angles all while providing increased fuel mileage. Because tuning is about efficiency with the cylinders and displacement you have and fuel limits inherent within those boundaries, this also means that making your car perform more efficiently often results in better fuel mileage too.

Its important to know that all tunes sold by E-tunez are tuned until they completely meet the criteria laid out in the tune type that was purchased, regardless of the revision count. In other words all of our tunes are tuned until they are complete. If a user purchased an Ultimate Tune with 7 revisions and the tune was not complete by the 7th revision, the tuning process would continue until the point it was, no matter the revision count, and no matter which tune type was purchased.
The revisions that come with the tunes are guaranteed minimum number. So if the tune is completed before reaching the minimum revisions (say it was completed at revision 5). Then that user has an extra two revisions that can be used at anytime in the future, even if modifications change, until they reach the minimum 7 revisions promised.
Think of unused revisions as free re-tunes, its a way of guaranteeing you get your monies worth. If your tune is completed earlier then expected then you still have revisions left that can be used for IAT compensation tuning in weather extremes or even modification re-tuning or as desired by you in the future, liking adding an intake or exhaust.
Many users come back months down the road to use up another revision just to dial things back in as the parts break in, even though their tune was completed earlier. Revisions make it easier to track these changes and allow you to get more for your money. The tune is not complete, until you recieve and email saying "Final Revision" and of course the tune would be looking near perfect at the point, some of the previous revision might suggest only need one log, or similar.
If a vehicle was tuned until complete, and then the user adds a few performance parts down the road (like headers, exhaust etc) then we offer a discounted tune called a Re-Tune for this situation, again it is tuned until complete.