Depends on the car. My car would det itself into oblivion at what most people run Mine is actually tuned into the 10's, but that's not normal for wrx's.

DSM's do have good combustion chamber design though... far superior to my suby at preventing det. So greaser is probably right.

 

exactly what i was going to say.

Depends on the car really as to what the perfect a/f ratios tune for. typically though...get some sort of knock detection deviece such as a knock link. then play around with the a/f ratios until you find a happy buffer zone between det and power.

wrx's suck...i have to tune mine for 11:1 for it to be happy. Luckly...there are huge injectors for that ^_^

 

i have my talon tuned to 11.8:1 and it runs excellent. i would not recommend going any leaner on pump gas as i don't trust pump gas much.

you have an EVO if i recall.. the EVO 8 MAF is really finicky.... you will need to retune everything you do intake related on that car.