Quattro Question
#2
Guest
Posts: n/a
Re: Quattro Question
In article <F1ucb.11858$gv5.8115@fed1read05>,
Not James <NotDisclosed@nospam.com> wrote:
>Is the Quattro full time AWD? If not, is it biased to the front or rear
>wheels and then switched to AWD as needed?
The Torsen system used with longitudinally oriented engines (other than
the A3/TT) is full-time.
The Haldex system on the A3/TT is front-wheel drive with the rears added
once slip is detected.
--
<a href="http://www.poohsticks.org/drew/">Home Page</a>
Life is a terminal sexually transmitted disease.
Not James <NotDisclosed@nospam.com> wrote:
>Is the Quattro full time AWD? If not, is it biased to the front or rear
>wheels and then switched to AWD as needed?
The Torsen system used with longitudinally oriented engines (other than
the A3/TT) is full-time.
The Haldex system on the A3/TT is front-wheel drive with the rears added
once slip is detected.
--
<a href="http://www.poohsticks.org/drew/">Home Page</a>
Life is a terminal sexually transmitted disease.
#3
Guest
Posts: n/a
Re: Quattro Question
Expanding on Drew's reply:
The original quattro system was full-time four wheel drive, with a 50/50
torque split between front and rear wheels. Audi engineers were convinced
that there were so many advantages of 4WD, and so few disadvantages, that
there was no conceivable reason that a driver might want to switch it down
into 2WD mode, so they didn't offer the option.
Later in the 1980s, the Torsen diff started to be used, which allowed a
variable torque split between front and rear wheels, varying beween 25/75
and 75/25 bias. In an interview at the time in one of the UK car magazines,
an Audi engineer said that this change was really made so that they were
seen to be updating the technology in the vehicle, and that virtually all
the time the torque split would still be 50/50, just the new setup has the
possibility to distribute torque differently if it felt it was required.
The Haldex system in the A3/TT is part-time, in that the rear drive is
brought in as required.
Mike.
"Not James" <NotDisclosed@nospam.com> wrote in message
news:F1ucb.11858$gv5.8115@fed1read05...
> Is the Quattro full time AWD? If not, is it biased to the front or rear
> wheels and then switched to AWD as needed?
>
>
The original quattro system was full-time four wheel drive, with a 50/50
torque split between front and rear wheels. Audi engineers were convinced
that there were so many advantages of 4WD, and so few disadvantages, that
there was no conceivable reason that a driver might want to switch it down
into 2WD mode, so they didn't offer the option.
Later in the 1980s, the Torsen diff started to be used, which allowed a
variable torque split between front and rear wheels, varying beween 25/75
and 75/25 bias. In an interview at the time in one of the UK car magazines,
an Audi engineer said that this change was really made so that they were
seen to be updating the technology in the vehicle, and that virtually all
the time the torque split would still be 50/50, just the new setup has the
possibility to distribute torque differently if it felt it was required.
The Haldex system in the A3/TT is part-time, in that the rear drive is
brought in as required.
Mike.
"Not James" <NotDisclosed@nospam.com> wrote in message
news:F1ucb.11858$gv5.8115@fed1read05...
> Is the Quattro full time AWD? If not, is it biased to the front or rear
> wheels and then switched to AWD as needed?
>
>
#4
Guest
Posts: n/a
Re: Quattro Question
Jep and more specific information about Haldex systems you can find here
http://www.haldex.com/index_main.asp
-Janne
> The Haldex system in the A3/TT is part-time, in that the rear drive is
> brought in as required.
>
> Mike.
>
http://www.haldex.com/index_main.asp
-Janne
> The Haldex system in the A3/TT is part-time, in that the rear drive is
> brought in as required.
>
> Mike.
>
#5
Guest
Posts: n/a
Re: Quattro Question
Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
in the snow twice during last years eastern snow storms. The snow was
fairly deep with an icy layer under the snow. A push got me going,
but while I was stuck, only the rear wheels were turning / spinning.
Is my Quattro bad (no known driving or handling issues) or is it
normal for only the rears to spin during certain situations? Thanks.
in the snow twice during last years eastern snow storms. The snow was
fairly deep with an icy layer under the snow. A push got me going,
but while I was stuck, only the rear wheels were turning / spinning.
Is my Quattro bad (no known driving or handling issues) or is it
normal for only the rears to spin during certain situations? Thanks.
#6
Guest
Posts: n/a
Re: Quattro Question
"Jim" <jim@none.no> wrote in message
news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> in the snow twice during last years eastern snow storms. The snow was
> fairly deep with an icy layer under the snow. A push got me going,
> but while I was stuck, only the rear wheels were turning / spinning.
> Is my Quattro bad (no known driving or handling issues) or is it
> normal for only the rears to spin during certain situations? Thanks.
>
I don't know the definitive answer to your question, but I do know that with
2 wheel drive cars, its common for only 1 wheel to spin. And it that case
you don't conclude that its broken and only 1 wheel is working properly. Am
I right in thinking that a limited-slip differential is supposed to help
prevent this effect? By transfering torque to the wheels that aren't
spinning? Well so much for the theory. Anyway, from the sound of it, I
would guess your car is behaving normally, but I am no expert.
Chip.
news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> in the snow twice during last years eastern snow storms. The snow was
> fairly deep with an icy layer under the snow. A push got me going,
> but while I was stuck, only the rear wheels were turning / spinning.
> Is my Quattro bad (no known driving or handling issues) or is it
> normal for only the rears to spin during certain situations? Thanks.
>
I don't know the definitive answer to your question, but I do know that with
2 wheel drive cars, its common for only 1 wheel to spin. And it that case
you don't conclude that its broken and only 1 wheel is working properly. Am
I right in thinking that a limited-slip differential is supposed to help
prevent this effect? By transfering torque to the wheels that aren't
spinning? Well so much for the theory. Anyway, from the sound of it, I
would guess your car is behaving normally, but I am no expert.
Chip.
#7
Guest
Posts: n/a
Re: Quattro Question
"Chip" <AnneOnymouse@virgin.net> wrote in message
news:bkuj70$6ab6t$1@ID-185713.news.uni-berlin.de...
> "Jim" <jim@none.no> wrote in message
> news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> > Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> > in the snow twice during last years eastern snow storms. The snow was
> > fairly deep with an icy layer under the snow. A push got me going,
> > but while I was stuck, only the rear wheels were turning / spinning.
> > Is my Quattro bad (no known driving or handling issues) or is it
> > normal for only the rears to spin during certain situations? Thanks.
> >
>
> I don't know the definitive answer to your question, but I do know that
with
> 2 wheel drive cars, its common for only 1 wheel to spin. And it that case
> you don't conclude that its broken and only 1 wheel is working properly.
Am
> I right in thinking that a limited-slip differential is supposed to help
> prevent this effect? By transfering torque to the wheels that aren't
> spinning? Well so much for the theory. Anyway, from the sound of it, I
> would guess your car is behaving normally, but I am no expert.
>
> Chip.
>
A full time 4WD performance car, as mentioned earlier, needs 3 differentials
in order to operate properly. A differential is basically a mechanical
device that allows the wheel which sits on the outside (longer radius) of a
road bend to spin faster than the wheel on the inside (shorter bend radius).
These devices are used on the axles that hold the wheels that are driven by
the engine and, in the case of a 4WD car, between axles. If no differential
is present then the driven wheels would spin at the same speed in a turn
thus rendering the handling of the car very unpleasant. Self-locking
differentials add to the classic "free" differential the ability to lock
(drive both wheels at the same speed) under certain conditions such as when
wheel spin occurs. For instance by locking itself, the differential, allows
to avoid the immobilization of the vehicle in situations such as when a
wheel sits on snow while the other sits on dry tarmac. In this case, the
absence of a locking device would send all engine torque to the wheel that
spins faster (the one on the snow) and the car would not be able to extract
itself. Locking the differential would split torque distribution on both
wheels thus allowing the car to move forward.
Ron
Taken from a website
#8
Guest
Posts: n/a
Re: Quattro Question
"Chip" <AnneOnymouse@virgin.net> wrote in message
news:bkuj70$6ab6t$1@ID-185713.news.uni-berlin.de...
> "Jim" <jim@none.no> wrote in message
> news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> > Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> > in the snow twice during last years eastern snow storms. The snow was
> > fairly deep with an icy layer under the snow. A push got me going,
> > but while I was stuck, only the rear wheels were turning / spinning.
> > Is my Quattro bad (no known driving or handling issues) or is it
> > normal for only the rears to spin during certain situations? Thanks.
> >
>
> I don't know the definitive answer to your question, but I do know that
with
> 2 wheel drive cars, its common for only 1 wheel to spin. And it that case
> you don't conclude that its broken and only 1 wheel is working properly.
Am
> I right in thinking that a limited-slip differential is supposed to help
> prevent this effect? By transfering torque to the wheels that aren't
> spinning? Well so much for the theory. Anyway, from the sound of it, I
> would guess your car is behaving normally, but I am no expert.
>
> Chip.
>
>
in theory the quattro has 3 diff's so you should see it spin all the wheels,
or it will spin each wheel in turn until 1 wheel stops spinning then it will
apply max power to that wheel to get you out and when that one starts
spinning agin it changes to another wheel, untill you are free...
Thats whats suppose to happen I think
Ron
In contrast if you were taking a fast corner and needed more purchase on the
rear of the car, it should transfer power there to stop the car from sliding
out, and then varies between front and back.
A good test is to find a quiet roundabout, when its raining, so slippery and
drive flat out round the roundabout, if the back end slides out before you
hit 60mph then somthing is up
<Warning I take no responsibility if you write your car off> )
Also try driving on the beach, on the sand, and floor it <accelerate hard>
from standstill, you should'nt get any spin, and should pull away nicely
unless you are driving an s4 or a chipped up 1.8T with 200bhp.
The car should pull away fast like your on the road, and not spin like the
S4 would as all 4 wheels put down so much power that the 4wd system acts
like a 2wd car and digs all 4 wheels into the ground
#9
Guest
Posts: n/a
Re: Quattro Question
My first Quattro was also an '01 A4 1.8tQTip and I never had such a problem
in that car or my current A6 2.7tQTip. It comes to mind that perhaps the
snow buildup had "lifted" the chassis so that the tires were no longer in
firm contact with the roadway and a push was all that was needed to get you
over the hump.
Jon
"Ronny" <Ron@ron.com> wrote in message
news:bkupff$7bh$1$8300dec7@news.demon.co.uk...
>
> "Chip" <AnneOnymouse@virgin.net> wrote in message
> news:bkuj70$6ab6t$1@ID-185713.news.uni-berlin.de...
> > "Jim" <jim@none.no> wrote in message
> > news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> > > Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> > > in the snow twice during last years eastern snow storms. The snow was
> > > fairly deep with an icy layer under the snow. A push got me going,
> > > but while I was stuck, only the rear wheels were turning / spinning.
> > > Is my Quattro bad (no known driving or handling issues) or is it
> > > normal for only the rears to spin during certain situations? Thanks.
> > >
> >
> > I don't know the definitive answer to your question, but I do know that
> with
> > 2 wheel drive cars, its common for only 1 wheel to spin. And it that
case
> > you don't conclude that its broken and only 1 wheel is working properly.
> Am
> > I right in thinking that a limited-slip differential is supposed to help
> > prevent this effect? By transfering torque to the wheels that aren't
> > spinning? Well so much for the theory. Anyway, from the sound of it, I
> > would guess your car is behaving normally, but I am no expert.
> >
> > Chip.
> >
> >
> in theory the quattro has 3 diff's so you should see it spin all the
wheels,
> or it will spin each wheel in turn until 1 wheel stops spinning then it
will
> apply max power to that wheel to get you out and when that one starts
> spinning agin it changes to another wheel, untill you are free...
>
> Thats whats suppose to happen I think
>
> Ron
>
> In contrast if you were taking a fast corner and needed more purchase on
the
> rear of the car, it should transfer power there to stop the car from
sliding
> out, and then varies between front and back.
>
> A good test is to find a quiet roundabout, when its raining, so slippery
and
> drive flat out round the roundabout, if the back end slides out before you
> hit 60mph then somthing is up
>
> <Warning I take no responsibility if you write your car off> )
>
> Also try driving on the beach, on the sand, and floor it <accelerate hard>
> from standstill, you should'nt get any spin, and should pull away nicely
> unless you are driving an s4 or a chipped up 1.8T with 200bhp.
>
> The car should pull away fast like your on the road, and not spin like the
> S4 would as all 4 wheels put down so much power that the 4wd system acts
> like a 2wd car and digs all 4 wheels into the ground
>
>
in that car or my current A6 2.7tQTip. It comes to mind that perhaps the
snow buildup had "lifted" the chassis so that the tires were no longer in
firm contact with the roadway and a push was all that was needed to get you
over the hump.
Jon
"Ronny" <Ron@ron.com> wrote in message
news:bkupff$7bh$1$8300dec7@news.demon.co.uk...
>
> "Chip" <AnneOnymouse@virgin.net> wrote in message
> news:bkuj70$6ab6t$1@ID-185713.news.uni-berlin.de...
> > "Jim" <jim@none.no> wrote in message
> > news:d7j5nvcb843pd4ke6efl30ftcepd7cqh1i@4ax.com...
> > > Related Quattro question: My 2001 A4 (1.8t, Tip, Quattro) got stuck
> > > in the snow twice during last years eastern snow storms. The snow was
> > > fairly deep with an icy layer under the snow. A push got me going,
> > > but while I was stuck, only the rear wheels were turning / spinning.
> > > Is my Quattro bad (no known driving or handling issues) or is it
> > > normal for only the rears to spin during certain situations? Thanks.
> > >
> >
> > I don't know the definitive answer to your question, but I do know that
> with
> > 2 wheel drive cars, its common for only 1 wheel to spin. And it that
case
> > you don't conclude that its broken and only 1 wheel is working properly.
> Am
> > I right in thinking that a limited-slip differential is supposed to help
> > prevent this effect? By transfering torque to the wheels that aren't
> > spinning? Well so much for the theory. Anyway, from the sound of it, I
> > would guess your car is behaving normally, but I am no expert.
> >
> > Chip.
> >
> >
> in theory the quattro has 3 diff's so you should see it spin all the
wheels,
> or it will spin each wheel in turn until 1 wheel stops spinning then it
will
> apply max power to that wheel to get you out and when that one starts
> spinning agin it changes to another wheel, untill you are free...
>
> Thats whats suppose to happen I think
>
> Ron
>
> In contrast if you were taking a fast corner and needed more purchase on
the
> rear of the car, it should transfer power there to stop the car from
sliding
> out, and then varies between front and back.
>
> A good test is to find a quiet roundabout, when its raining, so slippery
and
> drive flat out round the roundabout, if the back end slides out before you
> hit 60mph then somthing is up
>
> <Warning I take no responsibility if you write your car off> )
>
> Also try driving on the beach, on the sand, and floor it <accelerate hard>
> from standstill, you should'nt get any spin, and should pull away nicely
> unless you are driving an s4 or a chipped up 1.8T with 200bhp.
>
> The car should pull away fast like your on the road, and not spin like the
> S4 would as all 4 wheels put down so much power that the 4wd system acts
> like a 2wd car and digs all 4 wheels into the ground
>
>