What to choose?

You bought yourself a shiny new (or new-to-you) tenth generation Honda Civic or Accord, and you're looking to modify it. Great! What's the best bang for the buck modification you can do? Tuning, of course.

These cars are a ton more fun with a tune. That being said, you have options when it comes to reflashing the factory ECU. Over the course of the last couple years, I've had the opportunity to get very well-acquainted with these options. Let's get right to the pro's and con's of the popular reflash options.

Hondata FlashPro
Advantages:

• A product from a company who has a long-standing name in the industry. Everyone has heard of Hondata.
• Allows for actual tuning of the ECU's calibration, by giving access to a number of tables that control target lambda, boost pressure, ignition advance, various compensations, etc.
• Features a large number of available basic calibrations that are easy for a beginner to upload in a few minutes.
• Software allows for "live tuning" of various tables, allowing the tuner to make changes instantly without a lengthy full reflash.
• Hondata's "ethanol WOT fuel compensation" table on FlexFuel cars allows for a varying lambda target with ethanol content.
• The FlashPro Manager software loads fast, and has an appealing GUI. Navigation is intuitive.
• FlashPro unit registration with Hondata's server is lightning-fast.
• The "Mods" window makes for simple changes to basemaps for end-users.
• For non-Si L15 Civics, Hondata allows for disabling of the artificial 'forced rise' in knock control value above 5,000rpm or so. This changes the knock control logic to behave more like the Civic Si (reactive mainly to actual knock sensor activity).
• The Hondata Mobile app is available for both Android and iPhone users to monitor live data while the FlashPro is plugged into the DLC port.
• Hondata's support of the FK8 model specifically adds extra features like FlexFuel input compensation, a revised ignition-based traction control strategy, per-cylinder logging on knock retard, a custom "fuel pump duty" value to easier spot fuel pressure drops, and the ability to control/utilize Hondata's proprietary "fuel system upgrade".

Disadvantages:

• Hondata relies heavily on the factory limit logic. This causes throttle, ignition, and boost pressure oscillations that may cause discomfort during driving. Instead of targets, everything is a "limit."
• The software doesn't allow the tuner to edit the main ignition table load index (what Hondata calls the "Knock Ignition Limit" table). What does this mean? Once you move enough air to reach the final load column (what they refer to as "240% Air Charge" on the L15 Civic, for example), the ECU retains the same ignition value regardless if you continue to move more air under differing conditions (like raising boost pressure, colder weather, etc). Riding the last column leaves no room for the ECU to interpret load and apply ignition properly for higher load.
• Hondata retains the factory 18,000kpa fuel pressure targets on the L15 Civic models. Hondata likes to talk about "flow potential of the HPFP is much greater at lower pressure", which is partly true... Neglecting the fact that raising the target pressure makes the volume of fuel for any given injector duration greater (just like turning up the base fuel pressure on a port injected car makes the effective size of the injector larger). A direct injected engine only has a finite window of time to complete the firing of fuel into the cylinder during a combustion cycle (unlike a port injected car that can spray the injector at any point in the cycle, for as long as you really want). As engine speed rises, this span of time shortens. Once you exceed this usable window of time, you experience misfire. To combat the lack of available injection window, Hondata's default answer is to run leaner lambda targets in order to avoid running out of available injection window. This is fine within reason, of course, but you can only go so lean at high load before you start to melt things. When using Hondata with the factory fuel system, you're putting yourself at a disadvantage in terms of how much power you can make while maintaining reasonable lambda targets.
• For PRL "big turbo" kit users that bought in before the electronic wastegate support was standard (or users that prefer to use external boost control, using the older pneumatic wastegate), Hondata offers ZERO means to disable wastegate/boost control related DTC's. If you remove the factory wastegate actuator in favor of a traditional pressure-activated internal or external gate, you will toss P2565 ("Turbocharger Boost Control Position Sensor Circuit High Input") to be exact. This will disable "Sport" mode, and will constantly illuminate a large number of other system errors the entire time the engine runs. For users with the newer kit with that retains the factory electronic wastegate actuator, Hondata offers no extra wastegate control logic changes to get the best response from your larger Garrett turbocharger.
• 2020 Civic Si models do not log mass airflow sensor ("AFM" in FlashPro) frequency in the sensor data list.
• Certain 10thGen Accords do not log fuel pressure correctly in the sensor data list.
• The software does not allow for cylinder misfire counter monitoring, making it difficult to catch problems like failing injectors (a common L15 problem) before they lead to bigger problems.
• FlashPro units are locked to certain model/VIN families. A Civic L15 unit cannot be used on an Accord, an FK8, etc. If you own a 10thGen Civic and trade it in on a new Accord, you must purchase new hardware to tune your new car.
• For certain non-Si L15 models, Hondata's "Return to Stock" option does not return the ECU to the EXACT factory software number, which may raise concern if a Honda HDS tool is ever plugged in to verify the current software number.
• Hondata's custom support for FK8 models makes logging all sensor data correctly when the ECU is on the factory calibration impossible.

Verdict?

• Hondata's brand-recognition alone gets its foot in the door for many end-users and tuners alike, but the long list of drawbacks overshadows some of the really great highlights it has available.

KTuner
Advantages:

• A product from a company with a long-standing history in the industry (KTuner is brought to you by the same company behind the "Neptune" OBD1 Honda tuning platform).
• Allows for actual tuning of the ECU's calibration, by giving access to a number of tables that control target lambda, boost pressure, ignition advance, various compensations, etc.
• Features a large number of available basic calibrations that are easy for a beginner to upload in a few minutes.
• KTuner by default raises the target fuel pressure on L15 Civic models to 21,000kpa (a 16% change), making the effective size of the injectors larger.
• Target-based, not limit-reliant. Most limits the ECU would oscillate off of are lifted.
• Two different devices available to interface with the vehicle, one of which has a dedicated touchscreen display to view live data, reflash, record data, etc without the use of a laptop, or mobile app (KTuner Flash V2).
• KTuner Flash units can be unlocked from a vehicle and be used on a new vehicle of a different model/VIN family. If the car is listed as supported by the unit, it can be used. No need to purchase new hardware for a new vehicle model.
• Retail pricing for both the Flash v1.2 and Flash V2 models are lower than Hondata FlashPro.
• Various enhancements for throttle response, turbocharger response, wastegate actuator control logic and more are available to the end user via easy drop-down menus.
• For most Civic models, "On the Fly Map Switching" allows for multiple boost level targets available from the steering wheel's controls without having to reflash the ECU.
• The ECU's misfire counter is visible in the sensor data list, useful for diagnosing things like failing injectors before they lead to larger mechanical damage.
• The KTuner "Return to Factory" option restores the ECU to the exact original software number present at the time of initial setup.

Disadvantages:

• The software is fairly resource-intensive, and slower to open initially.
• The software's GUI is a bit more rigid in terms of navigation and window sizing.
• Initial registration of new KTuner units with the server can be difficult at times, especially if a less-than-ideal internet connection is present.
• No live tuning. All changes require a full reflash of the ECU, which means a dyno tuning session tends to take a bit longer.
• KTuner lacks custom features for the FK8 that Hondata has (FlexFuel, ignition-based traction control strategy, per-cylinder knock retard logging).

Verdict?

• While the "KTuner" brand name isn't as recognized, the system offers a much more complete tuning solution for the latest generation of Honda's using the Keihin ECU's. The background changes implemented way before any end user or tuner starts making adjustments alone sets the system apart from the competition.

Once more, this post is the culmination of experience amassed from the literal thousands of 10th Gen Civic and Accords I've had a hand in tuning (custom tunes, off the shelf tunes, and several starting calibrations I've aided in developing for numerous companies that focus on these vehicles), and there's nothing I'd like more than to see the "disadvantages" for all mentioned to be addressed by their respective manufacturers. I tune Hondata and KTuner products both every single day, and want people to make informed decisions based on facts, not just based on bandwagon tactics or social media "influencers".

Thank you.
- Derek