AE86 16v standalone - any suggestions?

[NoHachi]

woper Wrote:MS II EMS use 12x12 tune tables that means that there's 144 points for ignition and 144 for fuel. AEM EMS has 17x21. That gives at least 357 point. And You can multiply it.
That's the major different between very good EMS and EMS.

Not entirely.. PhatBob is right on that one. What you are trying to do is as best as possible approximate the continuous Volumetric Efficiency map through a limited series of points. The map usually has a set of hills and vallyes that correspond to the eigen frequencies of the inlet and exhaust tract. These are pretty smooth, so approximating them through linear interpolation can be pretty rough. By using non-linear interpolation (e.g. polynomial) you can in theory get a better fit to the VE map.

Obviously you need a minimum of 2 mappoints to define each hill and vallye correctly, regardless of what interpolation technique you are using.The more peaks you have and the sharper they are, the more you really need to define the VE map. Intense multiple peaks are a characteristic of well designed and executed intake and exhaust systems (4-1 ex, IRTB in).

The problem becomes even bigger when you start stretching the revband. The resonant frequencies pop up in the higher rpm area's too so you need more map points again.

The phenomena PhatBob describes has to do with the relative influence of the resonance peaks on the total engine throughput. They kinda get drowned out at high rpm levels, since the engine is already pumping a lot of air there. At low rpms the airflow is much smaller, so the resonant peaks are a big influence. Very hot cams produce very little airflow at these rpms, making the engine even more difficult to tune.

Anyway, linear interpolation will get you all the way to a safe map if tuned by someone capable. It wont extract 100% out of your expensive engine but will comfortably do 85-90%. Those last 10-15% is where it becomes expensive.