shayrgob

hey, so I'm used to standalones simply displaying pulse width in their fuel tables and then adjusting accordingly. However, w/ the megasquirt it is a percentage. Obviously a higher value is more fuel and a lesser value is less fuel. But what exactly is that percentage and how does it exceed 100%? Seems a little confusing.

thanks

Aussie Driver

Have a read of the MegaManual. It's all in there.

shayrgob

I did...I couldn't find it. Do you know what it represents? thanks

FoundSoul

iTrader: (5)

volumetric efficiency... it's essentially what percentage of cylinder filling occurs at a given load/rpm. (how efficient is the engine at getting the A/F into the cylinders at that load/rpm point). The ECU then does the math to calculate PW.

It's the reason you don't need 15 different correction tables like you do with an ECU that lets you put in a static PW at a given RPM. By tuning for the engines VE and letting it adjust based on IAT/CLT/etc using proven algorithms only minor corrections are needed for special circumstances.


http://www.megamanual.com/v22manual/mtune.htm#ve

shayrgob

thanks a lot Jerry! that's exactly what I needed to know!