338 hp saab 900 2-door

#11

johannes (johs (AT) size-nosepam-fitter (DOT) com) gurgled happily, sounding much
like they were saying :

Quote:

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them from
just uselessly spinning.

When i had a car with traditional north-south engine, the car would
roll a bit when I blipped the pedal; this is of course angular
momentum conservation. Similarly, a transverse engine will pitch the
car, but the effect is probably more subtle. Depending on the rotation
direction of the crankshaft, it could actually help traction. But the
effect is probably quite small.

Ummm, it's a C900. The engine *is* north-south.

#12

Adrian wrote:

Quote:

johannes (johs (AT) size-nosepam-fitter (DOT) com) gurgled happily, sounding much
like they were saying :

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them from
just uselessly spinning.

When i had a car with traditional north-south engine, the car would
roll a bit when I blipped the pedal; this is of course angular
momentum conservation. Similarly, a transverse engine will pitch the
car, but the effect is probably more subtle. Depending on the rotation
direction of the crankshaft, it could actually help traction. But the
effect is probably quite small.

Ummm, it's a C900. The engine *is* north-south.

Yes I know. But most modern FWD have transverse. Just wonder about the
crankshaft/flywheel rotation direction on transverse FWD cars.

#13

"riserman" <riserman (AT) optonline (DOT) net> wrote

Quote:

Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy
What a perfect illustration of the limitations of front wheel drive. Under
acceleration, the center of mass of the car moves to the rear and there's
not enough weight on the front tires to prevent them from just uselessly
spinning.

Probably wrong, but I saw it as him holding the car on the hand-brake for
maximum [childish] smoke. I mean, with that amount of alleged power he'd
either be stopped dead from wheelspin or troubling the horizon, not in
imminent danger of being outdragged by an Amish buggy.

#14

riserman wrote:

Quote:

Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear and
there's not enough weight on the front tires to prevent them from just
uselessly spinning.

The center of mass does not move under acceleration (except for a small
shift if the tank is not full).

--
th

#15

th wrote:

Quote:

riserman wrote:
Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them from
just uselessly spinning.

The center of mass does not move under acceleration (except for a small
shift if the tank is not full).

If it's not the center of mass that shifts to the rear under

acceleration, and you may well be right, what resolution of vectors
shifts to the rear? Is it center of gravity or something else?

Front wheel drive cars lose traction easily under maximum acceleration.
I know this because it wasn't hard to do even in my 1983 900 turbo.
That's why you rarely see front wheel drive race cars.

riserman

#16

riserman wrote:

Quote:

th wrote:
riserman wrote:
Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them from
just uselessly spinning.

The center of mass does not move under acceleration (except for a small
shift if the tank is not full).

If it's not the center of mass that shifts to the rear under
acceleration, and you may well be right, what resolution of vectors
shifts to the rear? Is it center of gravity or something else?

Front wheel drive cars lose traction easily under maximum acceleration.
I know this because it wasn't hard to do even in my 1983 900 turbo.
That's why you rarely see front wheel drive race cars.

FWD works well i everyday driving. In this case it is mostly beneficial
to have the engine weight over the driving wheels. I don't race my Saab.
However, ultimately RWD gives more control when sliding the car around.
In salon car racing, most of the cars are FWD because that is what you
get in the compact car class. It was acknowledged that the RWD BMWs
in the race had an advantage, this was counteracted by a requirement of
carrying an added extra weight. True performance salon cars are 4 wheel
drive.

#17

"johannes" <johs (AT) size-nosepam-fitter (DOT) com> wrote

Quote:

riserman wrote:

th wrote:
riserman wrote:
Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them from
just uselessly spinning.

The center of mass does not move under acceleration (except for a small
shift if the tank is not full).

If it's not the center of mass that shifts to the rear under
acceleration, and you may well be right, what resolution of vectors
shifts to the rear? Is it center of gravity or something else?

Front wheel drive cars lose traction easily under maximum acceleration.
I know this because it wasn't hard to do even in my 1983 900 turbo.
That's why you rarely see front wheel drive race cars.

FWD works well i everyday driving. In this case it is mostly beneficial
to have the engine weight over the driving wheels. I don't race my Saab.
However, ultimately RWD gives more control when sliding the car around.
In salon car racing, most of the cars are FWD because that is what you
get in the compact car class. It was acknowledged that the RWD BMWs
in the race had an advantage, this was counteracted by a requirement of
carrying an added extra weight.

Quote:

True performance salon cars are 4 wheel
drive.

All wheel drive is a compromise most of the time, in use on everyday cars
because the chassis and suspension engineers couldn't contain the power.

It works well in adverse conditions but increases drivetrain friction the
rest of the time and adds weight and complexity.

--
The DervMan
www.dervman.com

#18

"riserman" <riserman (AT) optonline (DOT) net> wrote

Quote:

Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy
What a perfect illustration of the limitations of front wheel drive. Under
acceleration, the center of mass of the car moves to the rear and there's
not enough weight on the front tires to prevent them from just uselessly
spinning.

that was delibrate pointless tiresmoking, on the quarter mile he seemed to
put the power down OK.....

#19

"riserman" <riserman (AT) optonline (DOT) net> wrote

Quote:

th wrote:
riserman wrote:
Jeremy Brown wrote:
I don't know what to make of this guy:
http://video.google.com/videoplay?docid=7570206935258612439&q=saab

Jeremy

What a perfect illustration of the limitations of front wheel drive.
Under acceleration, the center of mass of the car moves to the rear and
there's not enough weight on the front tires to prevent them from just
uselessly spinning.

The center of mass does not move under acceleration (except for a small
shift if the tank is not full).

If it's not the center of mass that shifts to the rear under acceleration,
and you may well be right, what resolution of vectors shifts to the rear?
Is it center of gravity or something else?

Front wheel drive cars lose traction easily under maximum acceleration. I
know this because it wasn't hard to do even in my 1983 900 turbo. That's
why you rarely see front wheel drive race cars.

well my rwd ford sierra with 110bhp had worse traction in the wet than my
FWD 185 bhp saab....

pulling off on wet roundabouts I'd get wheelspin through 3rd gear...

#20

johannes <johs (AT) size-nosepam-fitter (DOT) com> Jul 6, 2007 at 09:11 AM wrote:

Quote:

Adrian wrote:

johannes (johs@[EMAIL PROTECTED]
) gurgled happily, sounding much
like they were saying :

What a perfect illustration of the limitations of front wheel
drive.
Under acceleration, the center of mass of the car moves to the rear
and there's not enough weight on the front tires to prevent them
from
just uselessly spinning.

When i had a car with traditional north-south engine, the car would
roll a bit when I blipped the pedal; this is of course angular
momentum conservation. Similarly, a transverse engine will pitch the
car, but the effect is probably more subtle. Depending on the
rotation
direction of the crankshaft, it could actually help traction. But
the
effect is probably quite small.

Ummm, it's a C900. The engine *is* north-south.

Yes I know. But most modern FWD have transverse. Just wonder about the
crankshaft/flywheel rotation direction on transverse FWD cars.

Probably more of a temporary windup issue than much else unless your
engine mounts are stuffed.
BTW, if you were being pedantic, wouldn't the C900 be considered a
south-north?

Cheers