Hondata

I have recently had a number of FK8s in for diagnostics with poor running and lack of power and found the MAF sensors have been disconnected deliberately by the "Tuner" as they are supposedly mapping the cars SD and in their opinion running smoother than with the MAF and to not re connect the MAF sensor when questioned.

I am UK/Europe based and been working extensively with the FK platform since the first FK2s came out, then the FK8s and am now well into mapping the FL5s and owning all these cars have been able to spend a lot of time working out what works and what doesn't and in all this time and literally hundreds of cars that I've mapped on Hondata, Ktuner and direct to ECU I have never once needed to bypass the MAF sensor and in the cases where we max it out then we simply use the Hondata or PRL uprated MAF sensors and calibrate accordingly.

It is my understanding that the MAF sensor is essential for correct running of the engine and that correct calibration guarantees that the car cold starts OK when the O2 sensor is heating up and runs fine as well if and when the O2 sensor fails. Its also used in a lot of other functions like load calculations which is how the ECUs basically run and if its removed and the O2 sensor isnt working then you are at risk of causing serious damage.

Now. Has anyone else removed the MAF and tuned some other way using Hondata effectively in what this "Mapper" believes is Speed Density as looking at the calibration stored on the ECU all I'm seeing is normal tables just DTCs killed to mask the missing MAF control. (downloaded calibration attached)

Normally I would just think the "Mapper" has been a bit confused or trying to mask the over fuelling conditions caused when atmospheric BOVs are fitted as this is where I first heard of this being done but the thing is this "Mapper" is actually an official listed Hondata dealer and has said they have been working directly with Doug and Hondata at the highest level and told specifically to disconnect the MAF sensor and tune SD as its more consistent which makes me even more interested to know and learn if we have the possibility of an improved way of tuning these ECUs.

Cal is attached so if anyone can see something I'm missing shout out.

Hondata... If this is true spill the beans and share the knowledge so we can all benefit ;)

For anyone interested I reconnected the MAF, reset the killed DTCs, trimmed the MAF cal and immediately picked up 20bhp pretty much everywhere.
Customer is reporting its actually driving far smoother and more responsive and cold start is spot on... with the MAF connected and working as it should be.

Confused but willing to learn. :)

We have never recommended disconnecting the AFM. As far as I know it will put the ECU into a backup routine to work around the missing airflow input, which is going to be sub-optimal at best.

Hondata wrote: Thu Jul 13, 2023 11:13 am We have never recommended disconnecting the AFM. As far as I know it will put the ECU into a backup routine to work around the missing airflow input, which is going to be sub-optimal at best.

It's great to see this reiterated from your account. Thank you.

Hate to speculate, but... sure sounds like a "iykyk" tune calibration.

I am glad to have Hondata give their input on the matter and confirming my suspicion. I have also told some of my customers the same answer, as anyone trying to "hack" and run this ECU in a way that wasn't intended, it just increasing the risk of potential damage and ultimately asking for trouble.

To clear up a few things, this method does work if you know what your doing and why... 99% of people wont need this. Yes the proper way is to have enough MAF resolution for you particular setup... It is not recommended if you don't know what to look for or why its even used.

The MAF calibration affects the load calculation... I wont get into extreme details as I don't need to at this point, but there is a strategy to follow if one were to go this route. Nobody knows about it in that much detail because its not recommended even to the advanced tuner...

If done correctly the car will drive perfect and no power or reliability will be sacrificed. Also if done properly fuel trims will be within +/- 5%

The ctr is a full time closed loop vehicle, so the car may not run properly without a stock functioning wideband on purpose and it and will trigger a code to get your attention to fix the problem (change the sensor)... At no point does the ctr run open loop during normal operation. Only time is after a re-flash, a cold start, or some post starts. If your a person that relies heavily on fuel trims to correct your tune, you really don't want to try this method "that isn't recommended'...

This SD hack just uses a backup routine in the ecu... Remember the airflow through the engine is modeled... that's why this works if needed for diagnostic purposes or even to drive on if required...

Why or why not to use is subjective, but I wont go into detail as its not recommended and some people seem to get in there feelings about the topic.

I will say this... if one were trying to make a lot of power on the ctr and reached the ecu torque limit of 655 also known as 65535, you will need a MAF reading to get around it... The SD hack will limit you. You would need more software to get around if using the SD hack which isn't available to the public...

Think outside the box if you need to... staying inside it may limit you... both are ok approaches...

Remember people there is one thing to be correct, its another thing when one is trying to stroke there ego...

Happy tuning ladies and gents...

Cheers...