Anybody know where on the map and roughly how much timing should be pulled to convert a 93 octane map to 91? Im not really looking for perfection, but I was looking at Ben's timing map and copied most of his map into my msq except for retarding timing progressively from 3 degrees in low boost to 5 degrees in high boost. Does the rest of the map need to be retarded a few degrees as well since lower octane fuel burns quicker and may reach peak pressure slightly quicker? Anyway im gonna try it out and listen for pinging but i was just sort of wondering about this.

Bens map is shown here:
https://www.miataturbo.net/forum/sho...0&postcount=86

 

I would think you're being plenty conservative in boost.... assuming you bought Ben's car and you're running 91 octane in it. Using his map on any other car and you've got alot of other variables in the mix...

As for 100kpa and under, maybe 2 degrees out would be a good starting place...

 

well I sort of took your advice and pulled 1* from 20-100kpa ... 2* from 100-150kpa, 3* from 150-200, and 4* above that since i don't really plan to go beyond 200kpa. It ran pretty good and strong other than some spark blowout from too much gap. I also richened it up to about 11:1 AFR at 12psi. So far no pinging and this is about 4 degrees more advance in boost than ive run before. Ill see how it goes when i throw in some colder plugs and .25-.3 gap tomorrow.

As for the other variables, i have a gt2554r, 16x10x3 IC, 3" exhaust, and a little bit of diy headwork