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Old 12-11-2013, 07:16 PM   #52
Suberman
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Quote:
Originally Posted by Rayme View Post
It makes more power. All engines make more power with colder air as the computer dumps more fuel to keep the air fuel ratio.
Well, no, see that's the point. That's the easy answer and probably incorrect if the bmep is limited by a knock sensor system.

It's torque that matters, bmep at its highest level. Power is just a multiple of bmep. Mind you, bmep is a calculated number but it represents real force.

If colder air results in more fuel being added then superficially higher bmep should result. However, the engine can't take more bmep than the detonation limit allows. Since the knock sensor operates at peak bmep already and at all temperatures then colder air can't make more power. The ECU retards ignition (or reduces boost) so the supposed more powerful air fuel mixture develops exactly the same bmep as the thinner air fuel mixture at higher temperatures.

It seems simple to figure out but it actually gets quite complicated.
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