MicroSquirt.com read only forum (Jan.15,2018)

When using the MAP/Baro method, where the VE table Y axis is MAP/Baro *100, is the MAP multiplied in a 'boost comp' fashion (0kpaA = -100% comp multiplier, 101.2kpaA 0% comp multiplier, 303.6kpaA = 200% comp multiplier, etc.) or not? Cannot find any info that says yes or no. There ain't a table for it. If not the VE table is not VE, and the 1% steps become quite large.

Also it would be neat to be able to try MAP/EMAP via the MAPBaro method, but having EMAP (Baro) synchronously sample at the exh port near the valve. This might alleviate many of the inaccuracies over the entire operating range of the engine of MAP/EMAP, because its the overlap period that is the main influence on true VE, not an avg pressure. Even for NA apps, might be a better way of doing a Baro comp.

anybody? Still can't find a definitive answer.

There are 2 effects of choosing the Map/Baro option:

The load index used for interpolating in the VE, spark and afr target tables is Map x 100/ Baro instead of Map.

In the pulsewidth equation, the fueling is multiplied by (Map/ 100 kPa) instead of by (MAP/ Baro).

So for most cases, where there is no boost and near sea level, there is not a big difference since Baro is near 100 kPa. In all cases you multiply by Map, so boost will be taken into account.

Synchronous exhaust backpressure sampling is the way to go, but it's not as simple as it looks because you need to take into account transport delays.

Why be concerned with pressure transport delay on exhaust (EMAP) and not intake (MAP)? Same rules apply, right?