HP calculation

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jwaldrip
Posts: 33
Joined: Sun Sep 27, 2020 3:01 am

HP calculation

Post by jwaldrip »

Do you have to have a MAP sensor to set up the HP calculations in the Iefis. Challenger 10.4. I'm trying to figure out how to use the HP and lop rop functions. I have fuel injected io360 engine. Didn't think I needed a MAP sensor so I didn't get the rdac with MAP.
plippo
Posts: 10
Joined: Tue Apr 18, 2023 10:08 am

Re: HP calculation

Post by plippo »

The engine power can be calculated from equation:

HP = RPM * torque * scaling (depends on units)

The torque produced depends on:
  • compression ratio (engine specific constant)
  • volumetric efficiency (engine specific: depends on RPM)
  • Air/Fuel ratio i.e. mixture
  • ignition timing
  • MAP: i.e. "how much mixture is filled to the cylinder". varies between 30%-100% of maximum full throttle

Assuming that timing, F/A and VE "don't matter too much", leaves the MAP as the dominant parameter which has a huge effect. Therefore no HP measurement without MAP.
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