all wheel drive

According to Subaru of Australia and Subaru of America the default ratio for
the 4EAT in the Forester is 60/40 and for the same year Impresa GT it is
40/60.
"Yousuf Khan" wrote in message

 > peter wrote:
  > > I drive Subaru Forester X 2004 Automatic. Subaru's website says that
  > > "...All-Wheel Drive system (featured on models equipped with 4EAT) can
  > > anticipate wheel slippage and tranfers power to the front or rear
  > > with the best traction even before slippage occurs". What is the
  > > split under normal traction conditions - is it 50/50 like with
  > > 5-speed manual transmition models?
 >
 > 90% towards the front, 10% towards the rear.
 >
 > Yousuf Khan
 >
 >
 >> Stay informed about: all wheel drive 

"peter" wrote in message
 > I'm sure this topis was discussed plenty of times here but since I'm
new
 > to this could any one bother explaining this one to me one more time?
 > I drive Subaru Forester X 2004 Automatic. Subaru's website says that
 > "...All-Wheel Drive system (featured on models equipped with 4EAT) can
 > anticipate wheel slippage and tranfers power to the front or rear with the
 > best traction even before slippage occurs". What is the split under normal
 > traction conditions - is it 50/50 like with 5-speed manual transmition
 > models?
 >
 > Thank You:)

From the technical manuals:
For the 4EAT Phase 2 automatic transmission system using VTD (includes the
H-6 VDC)-
1) "Assuming the friction of the front and rear tires is the same (normal
traction condition), the power is split 54.55% to the rear and 45.45% to the
front"
2) "The TCM adjusts the duty ratio of the MPT clutch to maintain the optimum
transfer of power. A large speed difference in the rear to the front wheels
results in the MPT clutch locking the Read Drive Shaft to the carrier. Power
is then split 50% to the front and 50% to the rear."

John
 >> Stay informed about: all wheel drive 

From reading various places, my understanding is 90 front/10 rear usually,
going down/up to 60/40 if conditions warrant. I don't know about selected
first or reverse gear being 50/50.

HW

"peter" wrote in message
 > I'm sure this topis was discussed plenty of times here but since I'm
new
 > to this could any one bother explaining this one to me one more time?
 > I drive Subaru Forester X 2004 Automatic. Subaru's website says that
 > "...All-Wheel Drive system (featured on models equipped with 4EAT) can
 > anticipate wheel slippage and tranfers power to the front or rear with the
 > best traction even before slippage occurs". What is the split under normal
 > traction conditions - is it 50/50 like with 5-speed manual transmition
 > models?
 >
 > Thank You:)
 >
 >
 >> Stay informed about: all wheel drive 

I have read that selecting 1st or Rev. in the 4EAT switches it to 50/50.

Carl
1 Lucky Texan


Edward Hayes wrote:
 > According to Subaru of Australia and Subaru of America the default ratio for
 > the 4EAT in the Forester is 60/40 and for the same year Impresa GT it is
 > 40/60.


 >
  >>peter wrote:
  >>
   >>>I drive Subaru Forester X 2004 Automatic. Subaru's website says that
   >>>"...All-Wheel Drive system (featured on models equipped with 4EAT) can
   >>>anticipate wheel slippage and tranfers power to the front or rear
   >>>with the best traction even before slippage occurs". What is the
   >>>split under normal traction conditions - is it 50/50 like with
   >>>5-speed manual transmition models?
  >>
  >>90% towards the front, 10% towards the rear.
  >>
  >> Yousuf Khan
  >>
  >>
 >
 >
 >


--
to reply, change ( .not) to ( .net)
 >> Stay informed about: all wheel drive 

"John M." writes :

 > From the technical manuals:
 > For the 4EAT Phase 2 automatic transmission system using VTD (includes the
 > H-6 VDC)-

Except that the Forester doesn't have a VTD transmission,
which has a center differential. The Forester only has
a transfer clutch which is only used to send power to the
rear under certain circumstances (which have never been
defined by anyone publicly).

The engine on the Forester is directly linked to the front
wheels, while the rear wheels freewheel under normal conditions.
 >> Stay informed about: all wheel drive 

Carl 1 Lucky Texan wites :

 > I have read that selecting 1st or Rev. in the 4EAT switches it to 50/50.
 >

If it did this you wouldn't be able to turn the thing.
50/50 means a locked transfer clutch.
 >> Stay informed about: all wheel drive 

Paul Pedersen wrote:
 > Carl 1 Lucky Texan wites :
 >
  >> I have read that selecting 1st or Rev. in the 4EAT switches it to
  >> 50/50.
 >
 > If it did this you wouldn't be able to turn the thing.
 > 50/50 means a locked transfer clutch.

my 5MT is 50/50 all the time and I don't have trouble parking.
--
Dominic Richens | dominic DeleteThis @alumni.uottawa.ca
"If you're not *outraged*, you're not paying attention!"
 >> Stay informed about: all wheel drive 

?
I'm not sure I ubderstand this statement.
It doesn't mean the differentials aren't working.

Carl
1 Lucky Texan

Paul Pedersen wrote:
 >
 > Carl 1 Lucky Texan wites :
 >
 >
  >>I have read that selecting 1st or Rev. in the 4EAT switches it to 50/50.
  >>
 >
 >
 > If it did this you wouldn't be able to turn the thing.
 > 50/50 means a locked transfer clutch.
 >
 >


--
to reply, change ( .not) to ( .net)
 >> Stay informed about: all wheel drive 

Correct.
The 4EAT (Active AWD) is usually listed as 90/10 under steady-state
cruising. When hard accelerating or rear wheel slippage occurs it can go
up to 60/40 (maybe 50/50 in lower gears?). The 'duty solenoid 'c' gets
it's duty cycle shifted by the TCU to engage the MPT clutch less or more
as is required.(so I've read-something like 100hz). The
default(interrupte signal,broken wire) condition is full activation of
the MPT clutch. Installing the FWD fuse supplies 12V constantly. Forcing
full DISengagement of the MPT clutch.
The VTD 4EAT is approx. 55/45
I don't know if this yet different again for the VDC.

Carl
1 Lucky Texan


Paul Pedersen wrote:
 >
 > "John M." writes :
 >
 >
  >>From the technical manuals:
  >>For the 4EAT Phase 2 automatic transmission system using VTD (includes the
  >>H-6 VDC)-
 >
 >
 > Except that the Forester doesn't have a VTD transmission,
 > which has a center differential. The Forester only has
 > a transfer clutch which is only used to send power to the
 > rear under certain circumstances (which have never been
 > defined by anyone publicly).
 >
 > The engine on the Forester is directly linked to the front
 > wheels, while the rear wheels freewheel under normal conditions.
 >
 >
 >
 >
 >


--
to reply, change ( .not) to ( .net)
 >> Stay informed about: all wheel drive 

Paul Pedersen wrote:
 > "John M." writes :
 >
  >> From the technical manuals:
  >> For the 4EAT Phase 2 automatic transmission system using VTD
  >> (includes the H-6 VDC)-
 >
 > Except that the Forester doesn't have a VTD transmission,
 > which has a center differential. The Forester only has
 > a transfer clutch which is only used to send power to the
 > rear under certain circumstances (which have never been
 > defined by anyone publicly).
 >
 > The engine on the Forester is directly linked to the front
 > wheels, while the rear wheels freewheel under normal conditions.

Actually, no they don't completely freewheel. There is a non-zero minimum
friction in the front-to-rear clutchpack, so there is always some minimal
amount of power going to the rears. Depending on how tight the clutchpack is
set to, you can set the default AWD split at anything from 90:10 to 40:60
depending on Scoobie model.

Yousuf Khan
 >> Stay informed about: all wheel drive 

On Tue, 27 Apr 2004 15:41:10 GMT, "Yousuf Khan"
wrote:

 >Paul Pedersen wrote:
  >> "John M." writes :
  >>
   >>> From the technical manuals:
   >>> For the 4EAT Phase 2 automatic transmission system using VTD
   >>> (includes the H-6 VDC)-
  >>
  >> Except that the Forester doesn't have a VTD transmission,
  >> which has a center differential. The Forester only has
  >> a transfer clutch which is only used to send power to the
  >> rear under certain circumstances (which have never been
  >> defined by anyone publicly).
  >>
  >> The engine on the Forester is directly linked to the front
  >> wheels, while the rear wheels freewheel under normal conditions.
 >
 >Actually, no they don't completely freewheel. There is a non-zero minimum
 >friction in the front-to-rear clutchpack, so there is always some minimal
 >amount of power going to the rears. Depending on how tight the clutchpack is
 >set to, you can set the default AWD split at anything from 90:10 to 40:60
 >depending on Scoobie model.
 >
 > Yousuf Khan
 >
So where does the STi fit in? Does it use the same AWD system as all
the other subies? I know it has a DCCD. And 60R/40F is the standard
power distribution when running with it in Automatic mode.

BlueSTi
"Scary-Fast"
 >> Stay informed about: all wheel drive 

Yousuf Khan writes :

 > Actually, no they don't completely freewheel. There is a non-zero minimum
 > friction in the front-to-rear clutchpack, so there is always some minimal
 > amount of power going to the rears. Depending on how tight the clutchpack is
 > set to, you can set the default AWD split at anything from 90:10 to 40:60
 > depending on Scoobie model.

I realize Subaru would like you to think this, but I don't see how
it's possible. Unless it is locked, the transfer clutch will be
slipping, however slightly, which means that the rear end would be
turning less quickly than the front (everything else being cast
aside for the moment). But, since the front wheels are connected
directly to the engine what happens is that the front wheels
pull the car along and the :chassis: will cause the rear wheels
to turn, not the transfer clutch, since it's output shaft is turning
less quickly than the front (or at least wants to).

So, unless the transfer clutch is locked (which you want it to
be sometimes) nothing at all is transfered to the rear.
 >> Stay informed about: all wheel drive 

Dominic Richens wrote:
 > Paul Pedersen wrote:
  >> Carl 1 Lucky Texan wites :
  >>
   >>> I have read that selecting 1st or Rev. in the 4EAT switches it to
   >>> 50/50.
  >>
  >> If it did this you wouldn't be able to turn the thing.
  >> 50/50 means a locked transfer clutch.
 >
 > my 5MT is 50/50 all the time and I don't have trouble parking.

In a 5MT, you have a differential between the front and rear wheels. So
during turning and stuff, the front and rear wheels take slightly different
paths around the corners (the rears actually take a shorter distance). So
during turning, you don't actually remain at the default 50/50 torque split,
it adjusts to the appropriate split to let the wheels take the right path
around. In a 4AT, instead of a differential you have a clutchpack. So in a
clutchpack situation, when you're talking about a 50/50 split -- you're
talking about a locked 50/50 split. The Scoobie clutchpack actually pulsates
on and off like an anti-lock brake, to allow the front/rear wheels to follow
their own paths around corners.

Yousuf Khan
 >> Stay informed about: all wheel drive