Glenn
--ooo--- I like your answer. And no, I'm not the bashing-ego-fight type, so no biggie on the "cranky" bit earlier, because I have to write in general terms too and that often results in come-back questions from others. It's all fair.
I like the point you make about heat and the "where" in the system. When we start talking about heated intake charge due to intake restriction then we absolutely must agree that this is a. going to vary from car to car and b. agree that it is very small (which I think you already posted somewhere above). YES, I can agree that more heat in the wrong place equals less-dense intake charge and less F/I mix entering the engine.
Good debate, let me offer a couple of "devils' advocate" responses.
A TB also generates friction and a great deal of turbulence and therefore heat in that turbulence. Since we're talking about equal restriction in both scenarios, following the math (or no-freebie physics), then total restriction = total friction-to-heat numbers. Right? Then I think you are absolutely correct in the case where the physical layout of the intake has that heat pooling in the wrong place. that goes to point "a" above. Regardless, if total friction (equal in both cases) derives total heat (which would be the same derivative total) and they are the same, then your point is weakened, because, well, the end result is equal.
Every TB I've owned is heated by engine coolant to prevent ice-over. That can also diminish (not deny) our points of heat impact.
However (and I'm pleading my case):
Assuming a fully functional, O2-based feedback system, operating within parameter range, I fail to see, however how the heat-to-less-dense- air charge would impact mpg, as fuel flow is still based on actual, post-loss (be it restriction and air temp/density) flow/pressure accounted for in FI. EVEN IF the heat loss was somewhere upstream in the intake, resulting in reduced mixture density, the ECU only assigns fuel quantity according with the actual flow/density as determined by MAP/MAF, and then tweaked by O2 sensor.
That said, we are also at the limit of my understanding of these systems, so if I don't get it, I'll gracefully say, "I just don't get it." We are, after all, discussing mpg efficiencies that are likely less than, say, duct-taping the seams of one's hood and fascia...
Mikey!!!
--ooo--- I like your answer. And no, I'm not the bashing-ego-fight type, so no biggie on the "cranky" bit earlier, because I have to write in general terms too and that often results in come-back questions from others. It's all fair.
I like the point you make about heat and the "where" in the system. When we start talking about heated intake charge due to intake restriction then we absolutely must agree that this is a. going to vary from car to car and b. agree that it is very small (which I think you already posted somewhere above). YES, I can agree that more heat in the wrong place equals less-dense intake charge and less F/I mix entering the engine.
Good debate, let me offer a couple of "devils' advocate" responses.
A TB also generates friction and a great deal of turbulence and therefore heat in that turbulence. Since we're talking about equal restriction in both scenarios, following the math (or no-freebie physics), then total restriction = total friction-to-heat numbers. Right? Then I think you are absolutely correct in the case where the physical layout of the intake has that heat pooling in the wrong place. that goes to point "a" above. Regardless, if total friction (equal in both cases) derives total heat (which would be the same derivative total) and they are the same, then your point is weakened, because, well, the end result is equal.
Every TB I've owned is heated by engine coolant to prevent ice-over. That can also diminish (not deny) our points of heat impact.
However (and I'm pleading my case):
Assuming a fully functional, O2-based feedback system, operating within parameter range, I fail to see, however how the heat-to-less-dense- air charge would impact mpg, as fuel flow is still based on actual, post-loss (be it restriction and air temp/density) flow/pressure accounted for in FI. EVEN IF the heat loss was somewhere upstream in the intake, resulting in reduced mixture density, the ECU only assigns fuel quantity according with the actual flow/density as determined by MAP/MAF, and then tweaked by O2 sensor.
That said, we are also at the limit of my understanding of these systems, so if I don't get it, I'll gracefully say, "I just don't get it." We are, after all, discussing mpg efficiencies that are likely less than, say, duct-taping the seams of one's hood and fascia...
Mikey!!!
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