Horsepower loss in drive train

[James at ringsperformance.com]

> same drivelines (well more or less.)  If Dynapack's correct, and one is to
> apply the same TCF across the board to all three vehicles, why is, or
better
> yet where is the additional 70 to 80 hp Car C's chassis vs. say Car A, is
> sucking off the motor going?  Is there that much power being sucked up by
> the turbo to account for the difference?  Does an additional 290 bhp
> (420-130) really generate an additional, what 58 to 60 hp in internal
engine
> or transmission friction and other power losses?

It does.

That's why high-end street cars (Maranello) and most high-power race cars
use, for example, right-angle-differential (as in the rear axle) coolers.
The diff on the race car and your street car both eat, say, 6% of the power
passed through them. The street car is running 100 Hp, so 6 Hp (4.5 kW) ends
up as diff heat. This is pretty easy to shed just via ambient airflow at
reasonable temperature differences (say, the diff must be 43 dF hotter than
the outside air to tranfer that heat). The (NASCAR) racecar is running, say
700 Hp, so 42 Hp (31.5 kW) ends up as diff heat. This requires an amazing
temperature difference (say, the diff must be 380 dF hotter than the outside
air) to transfer via only over-the-surface airflow, so they need to use a
circulating-oil cooler.

FWIW, transverse engines don't have any right-angle gear sets (excepting the
spiders in the differential proper), and so they are inherently more
efficient than our cars.

cu, James Marriott
'84 4kq beater, 217k, for sale (BUY IT!)
'87 4kq (alias "late-B2 90q") with rare ersatz NG engine, 184k
'89 200q (MC1, ProconTen/no bag, 1.8 blah blah), 142k
Boise, ID, USA     http://www.webpak.net/~marriott/
www.ringsperformance.com