Megasquirt talk (split from robokills project thread)

[JMR_AW11]

You guys are a little optimistic if you think you can get the MS to run as sweet as a factory ECU.

The last time I looked at the latest MS2 it had 12x12 3D tables.

i.e. 12 rpm mapping points.

The standard Megasquirt has an 8x8 table which means 8 rpm mapping points. 8 rpm tuning points for an engine capable of 8000rpm?

The standard MS can only resolve the fuel into 100 microsecond resolution.
The stock AE86 ECU has 1 microsecond resolution. A hundred times more resolution.

Your 20 year old AE86 ECU has 17 (seventeen) rpm mapping points for the 3D ignition map. That is 17 points from 800rpm to 7200rpm in 400rpm steps. (17 is a lot more than 8 )

The standard MS is toytown technology.

I would guess the MS is designed for bigger lazier engines like in the US.

Not for the 4A-GE. Sure it will work but the 3D maps are too crude IMO.

Also, the factory ECU for the 4A-GE has around 40 (yes forty) lookup tables in it in total for the fuelling and ignition. Some are big maps but most are tiny little correction maps to keep the engine sweet when driving in traffic. All the program code is written to suit the characteristics of the 4A-GE engine.

I don't know how many lookups the MS has for you to play with but I will be very surprised if anyone can get a MS to run as well as a stock ECU.

How are you going to control the ignition timing?

You might be better going for a Unichip on your stock ECU.