file.newsgroup.cars.102980 Maven / Gradle / Ivy
From: [email protected] (Albion H. Bowers)
Subject: Re: Manual Shift Bigots
In a previous article, (Eric Youngblood) says:
>In article , [email protected] (eliot) writes:
>[race car stuff deleted]
Back to the F1 stuff for a second, note that the `auto' tranny in F1
_STILL_ shifts at the driver's command, not some preselected schedule. The
driver still controls the shifting, not the transmission.
>|> now, there is no dispute that in production cars, automatics are
>|> inherently more lossy than manuals. that is in theory. my point all
>|> along is that whatever mechanical advantages a manual has over an
>|> automatic can very easily be lost by a driver who isn't skillful or
>One thing that gives an automatic an advantage at launch is the fact that
>it has a torque converter vs a clutch. I know this sounds strange but,
>a torque converter multiplies the engine output when launching. It functions
^^^^^^^^^ ^^^^^^^^^^^
>as a sort of limited Continuously Variable Transmission. Typically you get
>a torque multiplication of 2 to 3 times depending on the stall speed.
I have yet to see a torque multiplier installed on a production automobile.
Such systems do exist, but none are presently installed in production autos
that I am aware of. These are commonly called viscous drive CVTs or
fluidic amplifiers.
>Contrasted to a clutch which merely slips when feathered (result is no TQ mult)
What the convertor _does_ allow is for the engine to be closer to its
torque peak during the launch before a clutched car can fully engage it's
driveline. Chevy proved it many years ago with the '70 Camaro (ETs and
terminal 1/4 mile times were close enough tpo be identical for 4 speed and
auto cars). Note that this is also the major reason that an auto car can
get away with fewer gears than a manual, the slip in the convertor makes up
for the fewer ratios (and before everyone starts yelling about the proposed
5 sspeed autos soon to be out, note that some manufacturers are using 6
speed manulas now).
>Once past lauch however, the converter begins coupling and the TQ multiplication
>effect is reduced, but by then you should be on the cam.
Correct.
--
Al Bowers DOD #900 Alfa Ducati Hobie Kottke 'blad Iaido NASA
"Well goodness sakes...don't you know that girls can't play guitar?"
-Mary Chapin-Carpenter