Why 3d map, if there is only RPM and angle information?

[Zendalar]

Ok..might be a stupid question, but since my car has the vacuum advance (retard actually) only to retard the ignition 10 degrees around idle and the maximum advance at redline would be 38 degrees (centrifugal).

So...whats the point of trying to to tune the 12x12 map, when in seventies, the factory only used 2d map, in this case, 1x 12 map ???

Fuel economy? DOes my driveability get better?....Or does it work if i just put the numbers i get from 2d map ?

[nfn15037]

Well the technology didn't exist back then. Their 1x12 map compromised somewhere. With a real load VS RPM table, you can map the ECU for any operating condition and not have to compromise on timing anhwyere.

[Zendalar]

But, if i made such a 1x12 map but in this case the same values on all 12 horizontal slots, it would work?

Is there a thread around that would tell how to turn the 2d map into a 3d map? I know the information is not in any of the sticky's...i think

[MegaScott]

I think you need to think differently when setting up your spark curve, Sure you can take your 2d stock dizzy curve and program that in, just make all the Map values the same for every RPM combination, But why? You have the added flexibility to have advance or retard anywhere on the spark map, regardless of RPM or manifold pressure.

Making a pseudo 2d map to start would be fine. When you tune to optimise spark you will change it.

I think it's a 3d map of sorts any way, you have vacuum advance, or intake pressure, you have RPM from mechanical advance, and you have the actual Advance that the engine gets, all happening at once, 3d. Just not as "on the fly" tunable as Megasquirt.