PLease help me get up to date/speed

[Peter Wales]

The big advantage with using engine speed and throttle position as
references in mapping an engine, is the exact repeatability of any set of
conditions. To get any air mass meter to give out a specific voltage at an
RPM is less easy, especially if you are trying to do this without a dyno. In
air mass meters I do include manifold pressure sensors. 

The problems which doing it without an air mass meter generate, occur when
the environment changes. If you do your programming at sea level on a sunny
day at 70 degrees, the programming will not be correct when it is raining
and you are half way up a mountain. Therefore, if you are going all out for
performance and ease of programming, use throttle and engine speed.
Otherwise, incorporate environment sensing with an air mass meter of some
sort. A hot wire air mass meter will cater for inlet temperature,
humidity,density (above sea level) and load.

The sequential injection systems add nothing to power! Most vehicles are
running with the injectors fully open at full power and so all injectors are
squirting a continuous stream of fuel into the inlet. At lower power
settings sequential injection will provide better economy and emissions. The
reason is inlet tract wall wetting and fuel droplet coalescing. If you
imagine the fuel as an onion, you burn off layers until it is all gone. The
smaller the droplet the fewer the layers and the more complete the
combustion. Leaving the droplets in the inlet allows them to coalesce and
create bigger droplets.

Peter Wales