Hi guys, before i head off to the dyno to tune ignition timing, I would very much like to get my fueling correct first. My current AFR table is pretty much a copy of Braineack's table as shown in https://www.miataturbo.net/megasquir...e-61587/page3/ and my VE tuning has been based on those targets.

Since pump gas is 98octane here in hong kong, my question is, how much, if at all, leaner should my AFR targets be compared to Brain's. thx.

 

I am also running the European 98Octan fuel and I am using the same AFR targets as anyone else. I don't see a point in running any leaner with this fuel.

 

European and US octane numbers are not the same. European are pure research octane numbers, US are the average of research octane and motor octane numbers (RO+MO)/2

Normaly I'd expect to use the same ignition table and fuel for 91 US Octane as 98 European Octane.

Tommy