Quote:
Originally Posted by afterburn 549
I was referring to the engine in this instance as it is part of the equation when accounting for loss.
Drive train loss is figured from total HP .
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Generally, for car's, HP is measured by OEM's as "Crank Horse Power", this is the horse power measured at the crankshaft.
Since taking the engine out to measure isn't often practical, most owners, and tuners, measure Wheel Horse Power, this is the measurement taken from the driven wheels driving the dyno. The 10% estimated loss figure, occurs from the engine at full power in top gear, and getting that power to the dyno at the wheels. You are confusing the number used for transmission loss - the difference between Crank HP and Wheel HP, for the loss in the engine system itself.
Losses involved in the engine itself, is much much much higher than 10%!!!!
When it comes to modification to an engine itself, you can increase crank HP, by decreasing the loss you are confused about. Reducing the restriction of the exhaust, by changing from crimp bends, to rolled bends, increases horse power, and decreases loss.
In take side modifications, are a little different, in that they allow more air flow in, but not always at an increase in efficiency, if the exhaust side can't match the new input, you probably still get more power, but drop efficiency.
For my 944's, I prefer to modify in ways that focus on lowering losses, reducing crank case windage, removing exhaust restriction, etc. These have minor gains, and the gains, are from making the system more efficient.
So the reason you think we are dense, is that the 10% number you pulled, is attributed as a normal loss for a manual transmission car from the crankshaft, to the wheels, when under full power in top gear. We see that number, and translate your first post into talking about that, as you mention "engine transmission loss".
What you seem to be speaking of, now that you've made a few more posts, is actually a loss of about 70-80% of the power the fuel is capable of.
When you add the Turbo, more air and fuel is rammed into the engine, so both the fuel and air used, and the horse power, are going up together. It may not always be a direct ratio, but you are increasing the fuel used in order to gain that horsepower, so the loss is increasing with the power.