Strange question perhaps but I was just wondering what it is that is changed. Is it simply ignition timing, or AFR, or what...?

 

anyone?

 

Not 100% sure what you are asking..

If you mean what is the difference between the UK 97 ron fuel map and the Jap 100ron fuel map then timing, boost and fueling, the whole thing will be different.

One developed on and for the UK car and the other the Jap car.. different cams, different engine componet make up in some cases, different turbo, especially if you are talking STi and depending on what year you are talking about?

Although it has been said the P1 UK map is identical to the STi5 Jap map..

 

Thanks, I think that answers my question. What I mean is, if I were to get my engine remapped for UK fuel but keep the boost exactly the same, what would be different? Which factors would be changed for the UK fuel. I would have said timing but I know ECU advances timing until it detects knock, so perhaps not. Is it AFR then, or is it something else?

 

Basically due to the less RON of the fuel the mapper would have to either remove some timing or remove some boost and adjust the fueling to get the correct AFR.

Power is closely related to both boost and timing so although you might not want to lose the boost, being able to run more timing can sometimes be quicker.
But then you are paying the mapper so if you want more boost then so be it.

Mappers I would contact are Pat@22b.com and Bob at www.brdevelopments.com