Working around the 300g/sec MAF Limit

[RichardB]

Hi Guys,

In the future, I was planning to change my stock intake to a larger diameter one (possibly the APS 70mm CAI or a larger custom intake if necessary). Based on other threads on these boards, I found the details I needed to create a spreadsheet which would give me the adjusted air flow values (g/sec) for a given MAF sensor voltage. Now I understand that the ECU is not able to deal with values greater than 300g/sec. Given a 70mm intake, I would be hitting 300g/sec at about 4.5 volts (with 4.93 volts showing 340 g/sec).

I am a complete newbie to tuning (lots of reading, no practice yet) therefore:
I don't really want to mess around with the injector values to make this work (as I have seen suggested before) as it would probably confuse the hell out of me at a later stage.
Is there a way to make a change in the ECU which would allow the ecu to read and deal with larger airflow values?

The spreadsheet is attached for anyone that is interested.

I have also heard of the speed density system by Freon, which sounds like it may be up to the task.
How would I be able to implement this on my ECU?
Is it just one table you "inject" into a ROM image, or would I need a complete ROM for my ECU, which I then customise for my setup?

For reference, I have a 05 UK STi (AJ840-8830).

Sorry for so many questions, but I want to understand.

Cheers
Richard