mmasse

I am starting to play with my DME ('97 993 Euro Vario Engine). I am doing this just for fun. I would like to learn as much as possible about how the EFI works and eventually be able to do some changes in the programing myself. I know this is a very complicated issue...which makes it more fun!!

So far I did some (a lot) of research on the Net (including this forum), bought some books, some of which I still have to read, but I am feeling that I am learning a lot.

I was able to get some info from my stock chip and a couple of Performance chips that I have for my 993 (Cyntex and CTune).

Using some of the demo versions of the tuning softwares, I was able to identify some of the Fuel and Timing maps on the "sea of data" coming from the EPROM. Please see graphs below.

My first BIG surprise was that the Cyntex data is IDENTICAL to the Stock EPROM. This really seems strange they haven't changed a bit. This seems like really unethical to me. I am posting a pic of the stock and Cyntex (actually also stock) chips.

But coming back to my learning process, I have a couple of question that maybe the experts in this forum can help me to answer:

-how can I get the units for the different axis on the graphs?

-how can I convert the hexadecimal (or decimal) info coming from the EPROM in actual Fuel Trim value (lambda) or timing advance data? Is there a specific formula for this? I tried to play with some formulas, but it seems that the relationship is not linear.

-does anyone knows where is the rev limiter info located on the 993 .bin file?

I would appreciate any help on this quest for knowledge. So far it has been great fun!!

Any comments on the differences between this two performance chip maps are very welcome.

Thanks in advance,

mmasse

this is the pic of the chips