[Phoenix7]

Originally Posted by mazdamaniac

There are several ways to figure out how much air is going into your motor. A MAF is the only method that actually measures it directly.
MAP-based systems need to compute the air mass by comparing pressure to temperature.

The OE PCM is very powerful. It has a different fuel map for each pair of gears and compensation tables for every possible operating condition.
It compensates for intake temp, coolant temp, throttle position, barometric pressure and vehicle speed. It even has compensation for time at a particular load!
It has different latency tables for each bank of injectors (to answer an earlier question, the Renesis has 3 injectors per rotor, instead of the old 2 injector setup; many of us are running the equivalent of a 500/1200 setup by splitting the secondaries into two staged groups for very fine fuel control in boost) and a progressive ignition dwell table that resolves down to .001ms.
There are separate throttle control tables for each gear to adjust throttle sensitivity independent of pedal position and "acceleration" tables that not only compensate for throttle opening rate, but can adjust for engine RPM delta.
There are tables to adjust when to be in open or closed loop for each gear and load level and trim for closed loop at different load levels.

Ignition control is equally dense with completely independent tables for the leading and trailing ignition, idle control matrices with inputs for temp, RPM, gear, vehicle speed, throttle position and delta and engine load.

The best part is that the PCM takes all of the operating condition data and compiles it into a single value - calculated load - that is then applied to the engine RPM to compute the target injector duration based on commanded target lambda.
You don't need to know how much duty cycle you need at a given RPM and boost level, you just tell it you want 11.5:1 at 6500 RPM and it does the rest.

If a Power FC is a knife and a Haltech or Motec is a scalpel, the OE PCM is a laser.

The MAF on the RX-8 is sitting in a 3.375" i.d. tube and driven on a 5v circuit. It has enough resolution to see .001 g/sec variations at idle (~6 g/sec) and still measure out to ~360 g/sec at full load.
For those doing their due diligence, that is about 47 pounds of air or 450 HP.
Realistically, I'd say the OE MAF is pegged at 420 crank HP.
Of course, you could just put it in a slightly bigger housing and rescale it.
Or, you could replace it with the MAF from a Cobra.

On a draw-through application, a boosted motor is going to vent after the MAF, so metered air is allowed out of the system and an over-rich condition may happen between shifts, etc.
In practice, this is negligible with proper tuning, but it can be completely negated by recirculating the BOV.

so, the electronics are capable of reaching high HP goals. How about the motor itself? Why are the turbo applications yielding such little hp?