A popular "mod" to the Miatas engine is to advance the spark engine from the factory 10 BTDC to 14 BTDC, this moves the peak torque earlier in the rpm range and is claimed to also increase horse power. Now as long as the mixture does not detonate/ping in the combustion chamber before the firing event is this sort of advance safe? Can it put extra stress on the crank/seals? How far can you go with something like this? Can you for example go to a 20 degree advance with the highest octane fuel? How is spark advance generally safe for engines?
People usually do this by changing the cam angle sensors position by rotating it anti clock-wise. Can the same be achieved by changing the timing between the cam shaft and the crank pulley or is this a different type of modification?