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Tuning a Honda K20 with Hondata FlashPro

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Hi guys,

I started the whole course recently, because I have always found modifying and tuning cars very interesting but never had the chance to learn about tuning an ECU. Now, with some of the courses completed I´m checking one of my cars ECU, on a Honda Civic Si K20, and I found a little bit strange the CAM ANGLE and IGNITION maps, maybe there is a why or maybe the before owner´s tuner didn´t know what he was doing at that time.

First comparison: Ignition Low and High Maps

- On stock maps timing increases as the cam angle increases.

- On tuned maps he set the same ignition timing for all cam angles.

Comments: This guy reduced ignition timing on most of the map and according to what I´ve learned here when we are tuning or reflashing an stock ECU, we want to add some ignition timing than stock to get more torque from a stock engine which comes very limited for more safety. I don´t think Honda engineers are wrong by setting higher values of ignition timing for safety.

Second comparison: Cam Angle Low and High Maps

- On stock maps cam angle increases as MAP/RPM increases.

- On tuned maps I don´t really know what or how he did it.

Comments: He reduced cam angle in comparison with CAM ANGLE LOW stock map in some areas (e.g. at idle area) and for CAM ANGLE HIGH map, he just set almost all map in 50 degrees cam angle which I don´t even know the car is able to get this angle because stock maps gets to a maximum of 40.

I just want to understand more about the subject and be sure that what I have been learning is right and perhaps get some recommendations.

Also, I would like to know if it is correct that a way to start my first tunes on my Civic K20 with Hondata Flashpro and on my Prelude H22 with AEM EMS, is making a comparison with the stock map and start modifying it from there because I´ll be sure which is the low limit that Honda Engineers set, or if it´s better just start from 0 as you guys explain on videos. I just want to find a way to start getting familiar with tuning before going to rent a dyno and waste some money.

Thanks in advance.

Attached Files

Hey, anyone suggestions?


Some tuners like to set all maps the same both fuel and ignition for both high and low cam and all cam angles.

Basically this is because , once you get the fueling close enough and timing you will play with your vtec and cam angle maps and tune these first. Once the cam angle maps are tuned this determines which fuel and ignition map it uses/interpolates between. Hence have fuel maps a 0 10 20 30 40 high and low.

Now theoretically this should never change and once again for simplicity you can set all fuel maps for low cam the same and all maps for high cam the same, then tick the box which says "modify all tables" and you only need to work in 2 fuel and ignition tables (high and low)

With ignition timing, when you say you add some ignition timing to increase torque, this isn't always true, its all about reaching MBT (Watch webinar here https://www.hpacademy.com/previous-webinars/dyno-tuning-ignition-timing/) and I find Honda are pretty good from factory and once you get up around 30 degrees (on a stock motor) then don't do much more.

With the cam angle settings, you will most likely find that the 50 degree advance on high might not actually ever happen. As I am sure you're aware all High maps are activated when Vtec/high cam is engaged. Which depending on the circumstances it might never go into the 50 degree areas. For example if vtec kicks in at 5500rpm it will only see 45 degrees of advance. The 50 could be there for keeping things looking smooth. Also Vtec might have to be at X MAP or TP so won't go into the 50degree advance on the light throttle stuff.

50 is a lot though and I am pretty sure they max at around 45-46 degrees.

At the end of the day though you need to give the motor what it wants and test all angles, vtec points, fueling and ignition timing.

The Hondata KPro is quite an advance/complex system and takes some time to get your head around it.

Technically you're suppose to set your cam angle to 0 everywhere and vtec high (like 9000rpm) then tune your low, 0 angle fuel and ignition map, then set cam to 10 everywhere and do repeat for the 10 degree fuel and ignition map, then 20, 30 and so on.

Then pull your vtec down and do the same for high cam. Then once all these maps are tuned no matter where you set the cam angle or vtec point the tune will be 100%.

To be this is an extremely long and unnecessary process, as I said if you set cam angle and vtec points early on (by doing runs with cam on from 3000rpm the off and overlaying the 2 runs, and also changing cam angle each run to find the sweet spots) then once these are set you can set all maps the same for all angles. Leaving you only 4 maps in total (fuel low, high, ignition low, high) instead of 24maps.

Then once you're closer to almost finished with the tune I tend to go back and play with the cams a little to see if there is any small gains now that fueling and timing is bang on.

I hope this makes sense and helps. As I said the KPro is advance/complex and hard to explain

Chris I can't thank you enough for this explanation, it's exactly what I needed to understand!

thanks mate!

Chris, thank you so much for that explanation, really useful.

So, I believe I will start my practical experience tuning only the fuel maps just for now, starting from stock ignition and cam angle calibration since for that I would need some time on the dynamometer to make it right.

Thanks again.

note, that hodata provides some really good bases maps to get you started, i would recommend starting with one of these.

Hi again,

What do you guys could tell me about knock monitoring with Hondata Flashpro?

I´ve read a lot of forum saying that we should disable knock tables (because they only control fuel octane) and tune ignition from 0 to reach MBT without knocking as I´ve learned here.

I´m asking this because I was taking some datalogs to monitor the stock values, and I got the "Knock Count" display showing values such as 22 to 30 even though I'm using 95 octane fuel.

Thanks in advance.

I have always disable the knock control on the Hondata, Last car I tuned on KPro I was having issues with the knock detection pulling timing when there was no knock and giving me stupid numbers in my ignition table (knock control was removing a constant 5 degrees). Even after altering knock maps it still wasn't right. I disabled the knock control and tuned the ignition table to MBT (engine was not knock limited).

Most K20a engines I have tuned I have found not to be knock limited over 3000rpm anyway, although this is on 98 octane fuel.

Other people might suggest another way, I personally don't use the knock control on the KPro

Hey, i have a question regarding the first question (cam-angles):

All the tunes i found sofar, have different fueling values for each cam (0 10 20 30 40 50). Now, what i understood from the 3rd post by Chris is, that its unnecessary to have different fueltrims on different cams - thats how i understood it from the lesson as well!

But that leads me to the follow-up: Why do so many tuners make the effort to tune each cam?

Thanks, Mark

i wouldnt know why they do it i guess that is a question for them to be asked

Regards Ross

Hi Tuneboy,

It's been 4 years from this post, now I have tuned a lot of Honda for a profesional race here in Mexico.

I wouldn't copy all maps the same even if you know that always you will be around 30 degress of VTC and high maps after 4,500RPM. I did it at the beginning but then I realized that any failure on your engine, VTC sensor or solenoid, VTEC or crank sensor will disable advance of cams and VTEC so you will be on low maps and 0 degress VTC and if you increase timing and fuel on the tables you are not touching while you're tuning and you get into them because of a failure you could get troubles and also it's not best practice to tune all tables turning off vtec and tuning all angles.

Here is what I find easier and with better results:

1. Dataloog cam angle and vtec then go increasing or decreasing all the tables by the same amount of FUEL and in a smoothie way. Remember NO big changes.

2. Add timing to all the tables by the same amount also only on zones that you're touching while you're tuning and then try to smooth them (I don't like smooth function from Hondata, I do manual, horizontal and vertical interpolation).

3. Move VTEC window decreasing it by 250RPM from you're now and see where it makes a better linear power curve (this can change depending on engines, camshafts, altitude, that's why is not the same for every car).

4. Go with you high cam angle table only in the zones you're touching and increase them by 2 degrees each run and see where you find better power curve.

5. Repeat step 1 and 2 for fuel and ignition to make sure everything goes right.

This process will take you maximum 2 hours on dyno after you get used to Hondata software, logging and know better this engines.

Let me know if you need anything else I can help with!

Regards, Victor.

Hey Victor do you do a lot of tuning for K series turbo cars? If so can I ask you some questions? my email is hawkeyeog@gmail.com

hope to hear from you soon

Hi Otis,

Yes, tell me on this forum so everybody can read and learn also!


Hi Victor I was reading your stories above and learned a little more in tuning the cam angles for the k series. I am new to tuning K- series and want to learn more. My question is how do you best tune the cam angles on the street? does any body here have experience on the street? Like what should i do with the cam angles for lets say a stock K20A2 with just bolt ons, leave idle area at 0 , then going around 30 degrees cruising area , 40 to 50 degree in and above VTEC point then around 7K start lowering it to around 25 degree??

If have any advise let me know. Most of my tunes are on the street.


Hi Audy,

To be honest with you you need to be very sensitive to those changes on the street. If you only have bolt-ons I wouldn't even bother touching too much cam angles tables, difference could be like 1-2HP (which you can't feel on the street).

I will only advance cam angle high speed after 6,000RPM all the way to a starting point of 20degrees and start testing because oem setup is very conservative on these ones.

Best you can do to learn how cam angles can affect your tune is on dyno.

Good luck!