Hondata

What limitations could I find tuning AFM vs MAP with a Rotrex SC?

I always worked with MAP tuning, and reading about AFM tuning I can´t adjust now the AFM flow because I don´t have stock injectors.

MAP tuning is so much better for forced induction and larger injectors.

civicRSA wrote:MAP tuning is so much better for forced induction and larger injectors.

Thanks for the response.

Could you explain a bit why is so much better? Because with AFM (after adjusting the flow, seems much easier adjusting the WOT table.

I think it´s more dangerous because if the O2 sensor or the AFM fails, could be a serious problem with the real mixture (Ok, if we are going to be catastrophics, any option it´s dangerous :D ). But I don´t know what more problems could be.

With MAP tuning the motor will run a lot better. There are also extra parameters for ignition and fuel that are not available with AFM tuning. For example. Individual cylinder ignition trim

And why it´s necessary to adjust first the AFM flow with the stock injectors?

Itsuki wrote:And why it´s necessary to adjust first the AFM flow with the stock injectors?

Anyone? :(

Because changing the intake will cause the AFM to read incorrectly. First you then tune for the different AFM reading, then for the larger injectors.

I don´t want to open another topic to blow up the section.

I have a problem with the AFM calibration. The car has a Rotrex C30 kit, 750cc injectors, walbro fuel pump, custom intake header.

The rotrex doesn´t charge. When it reachs some rpms the car suddenly goes lean.

Look the first datalog at the minute 6. The injectors for an instant are closed when the fuel status goes open driving.

At the road it do the same with WOT but the injectors are open all the time (2 datalog attached).

At first I thinked that it has an air leak, but now I´m confused.

When I upload a starting calibration for MAP, the car starts (better than with AFM calibration) but suddenly goes lean and shut off (3 datalog attached).

Any help?

Your short term fuel trims show that the fueling is a long way from where it should be. How have you calibrated the AFM flow for the intake and the injectors? Without seeing the calibration I would open up the bypass so you don't make boost, put the stock injectors in and then tune the AFM voltage/flow until the fuel trims are better. Then put the injectors in and change the AFM table.

Also your MAP sensor looks like it is reading low. What is you elevation?

If you have an air leak (intake or exhaust?) then fix that, as it will affect your lambda readings.

Thanks for the response.

The Rotrex is mounted after the throttle body.

For the AFM calibration I skipped the step of adjust with the stock injectors after I changed the intake for a custom CAI (Yes, I know that you adviced me before to make it with the stock injectors. Please, don´t ban me)

But for me isn´t a matter to go with a MAP calibration, but now I was trying to achieve some boost to localize that it´s there any leak in all the intake after the rotrex (IC, piping and intake manifold). And when I charged the MAP calibration and the car couldn´t hold started more than 10 seconds, I tried a calibration in AFM that "works".

Looking the datalog that I posted of the MAP calibration, what do you think about the reasons to go leaner and stop?

My elevation here it´s about 800 meters over the sea.

I attach the MAP calibration. It´s basically the one´s who cames with the FP for 750cc injectors.

Had the same problems with TTS's starting calibration!
Could not make the engine run more than few seconds and the problem was on the 750 fuel injectors adjustments which were totally wrong!

check out here what the guy that managed to start up my car says!

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