[urq] Optimum shifts - there was a program...

[Brandon Rogers]

This thread has contiued to educate me.  And I've been experimenting with
shifts a little bit, unfortunately without a stopwatch.  Thanks for all the
input.

There are several racers, tuners, etc on this list--have any of you put your
modded 10V turbo on a dyno and produced graphs or charts we could see?

Brandon
'84 ur
'98 A4



----- Original Message -----
From: "Fundsalo Racing" <fundsaloracing at yahoo.com>
To: <bbell at surview.com>; "Brandon Rogers" <brogers at terrix.com>; "urquattro
list" <urq at audifans.com>; <quattro at audifans.com>
Sent: Sunday, April 21, 2002 5:28 AM
Subject: RE: [urq] Optimum shifts - there was a program...



I believe your points are 100% correct. If you shift
too soon you'll noy only be in a higher gear, but way
down on the curve. If you hold the existing gear to
still be up on the curve after the shift to the next
higher gear you might sacrifice speed/time due to
drop-off in total torque becuase the engine output
rolls-off so fast that staying in the lower gear
longer is less effective Vs shifting up.

Somewhere, I had found a 'Basic' progam that accepted
toque/HP values at different RPM points, final drive
(I think) and all gear ratios and the program computed
optimal shift points output in RPM. This is what you
really need. My program was lost many lifetimes ago.
Anyone got anything similar?

There might even be such a computational engine on a
high-performance website somehwere, if not, sure
sounds like a good project for someone so inclined!

-glen

OOOO


--- Bruce Bell <bbell at surview.com> wrote:
> OK,
>
> I Assume we are talking of straight line
> acceleration here. A road course
> adds other considerations.
>
> For computational purposes it makes no difference
> whether you use Torque or
> horsepower curves. Remember, horsepower has a linear
> relationship to torque.
> Horsepower, quite simply, is how fast a motor makes
> torque.
>
> Since we are talking shifts, that means we are
> talking gear ratios, and the
> transmission is by definition a torque multiplier.
> so...
>
> By way of example, assume an 016 transmission with
> 3.60 first and 2.13
> second gears in a stock WX urq. If you shift at 5500
> rpm in fist (160 hp
> /5500 * 5250 = 153 ft lbs.), the car is at that
> moment producing 550 ftlbs
> (153 * 3.6) of torque. If you were to arrive in
> second gear at the torque
> peak (you won't) you would only have 362 ft lbs of
> torque available (170 *
> 2.13). Obviously you need to accelerate past the
> point of peak hp prior to
> shifting. In reality, given this example, you could
> continue until torque
> dropped to around 100, (wherever that is) and still
> make more torque than
> you would in second gear..
>
> To summarize, you stay in the lower gear until it is
> less productive than
> the gear you are shifting into by the above example.
> It is all about power
> at the wheels, maximize it!
>
> Bruce
>
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=====
-glen  "Upon common theaters, indeed, the applause of the audience is of
more importance to the actors than their own approbation. But upon the stage
of life, while conscience claps, let the world hiss! On the contrary if
conscience dissapproves, the loudest applause of the world are of little
value."

John Adams

OOOO

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