Quote:
Originally Posted by orange4boy
I have heard of this effect but have not been on a trip high enough to see. I know high altitude is better for aircraft FE. Must be for the same reasons: lower drag from thinner air = higher ground speed per engine revolution. You will read the same airspeed but have higher ground speed.
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I would suppose "airspeed is airspeed" at any altitude or air density. And as far as taking off, you should fly INTO the wind to get the airspeed up for the lift you need-- groundspeed is not really a factor on takeoff (maybe a lower groundspeed helps as there is less drag from the wheels and such, but that might be a marginal concern).
Otherwise, yes, high altitudes result in less drag-- the supercharger just makes sure the engine can still run in the rarified atmosphere.
What I need (or think I need) is a light that will come on when the supercharger comes on -- the supercharger is not full-time, but is engaged by a signal from the ECU.
I suppose a vacuum/boost gauge would do the same thing, more or less, but having a definite signal when boost is on would be interesting. One thing I want to avoid is the potential for detonation and potential spark retarding when boost is on, but I'm not sure if running with lower dynamic compression (unboosted) is actually more wasteful than boosted anyway. I suppose that running unboosted a lot will reduce pumping losses since the static compression ratio of the 2TZ-FZE is 8.9:1 rather than 9.3:1, but I'm just guessing at that.