what's the faster wagon?

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~^ beancounter ~^

what's faster...the 99-01 v70r's...or
the x country turbo wagons?

richard
colorado
 
~^ beancounter ~^ said:
what's faster...the 99-01 v70r's...or
the x country turbo wagons?
Click to expand...

What is fast, top speed or 0-60?

The '01 V70 T5 had 247 HP, and weighed 3368 lb

The '01 XC70 had 197 HP and weighed 3699 lb.

Geared properly, the T5 should definitely be faster.
 
0-60 speed...and...the year i am considering
is 2002 ... awd t5 vs. awd r ... right? those would
be the two fastest?....i imagine the r would edge out
the t5 by a bit...then it would come down to auto
vs. manual tranny?
 
T5 is a tuned "cooking" engine, R is "Race-tuned". So car for car R must be
faster all round than T5. Mind you the T5 fitted in the V50 is very very
fast but that is a different model chassis.

Cheers, Peter.
 
peter...so, the r series is really "built to go" from
the chassis up...lots of items different...i may
be wiser to do the "r" series...i want a fast, solid
performing wagon...that i can drive hard ocassionaly
when i want....
 
~^ beancounter ~^ said:
0-60 speed...and...the year i am considering
is 2002 ... awd t5 vs. awd r ... right? those would
be the two fastest?....i imagine the r would edge out
the t5 by a bit...then it would come down to auto
vs. manual tranny?
Click to expand...

and the weather. When the roads are rain-slickened, the AWD will be
about twice as fast as the FWD. One thing that entertains me is to
floor the throttle in wet weather in my XC70. I have a '01 viscous AWD
and it hasn't shown a single flaw. On wet roads I can floor the
throttle and not feel a single bit of slip. The Haldex is supposed to
be even better.
 
"The Haldex is supposed to
be even better. "

and the haldex starts in 2002 v70's?
did it also start in 2002 for the "r" series v70's??

thanx
 
That is because of the torque limiting factor brought into play when the
transmission senses conditions likely to promote wheel slip. It has nothing
to do with the FWD wheel spin caused by a lessening of the weight on the
driven wheels as the weight transfers rearwards under acceleration.

Cheers, Peter.
 
It might have something to do with the fact that wheel torque is limited
by the traction and not the engine power, hence having maximum torque on
all 4 wheels give twice as much acceleration as maximum torque on 2
wheels.
 
Where did you learn your physics Stephen? You don't have that much traction,
which is limited by the grip of the four little footprints of tyre on the
road surface. You want to see four-wheel spin? Switch off the traction
control.

Cheers, Peter.
 
guys...is there such an animal as a 2004 or 2005 v70r...or are
the r wagons only in the v60r version (in recent years)?..

thanx...
 
Peter K L Milnes said:
Where did you learn your physics Stephen? You don't have that much traction,
which is limited by the grip of the four little footprints of tyre on the
road surface. You want to see four-wheel spin? Switch off the traction
control.
Click to expand...

Speaking of physics, an interesting fact is that the area of the footprints
of the tire have no effect on the traction, they tires could be as wide as
the car and they would still slip just as easily. It's all in the weight and
the frictional coefficient of the material.
 
James Sweet said:
Speaking of physics, an interesting fact is that the area of the
footprints
of the tire have no effect on the traction, they tires could be as wide as
the car and they would still slip just as easily. It's all in the weight
and
the frictional coefficient of the material.
Click to expand...
I think the limitation of the theory as applied to car tires is the strength
of the rubber compound. Under stress the rubber tends to tear away, reducing
traction for tires that are below a threshold width (determined by the
rubber compound).

Mike
 
Stephen Henning said:
It might have something to do with the fact that wheel torque is limited
by the poor traction and not the engine power, hence having maximum torque
Where did you learn your physics Stephen?
Click to expand...

At the Oregon State University and the University of Pennsylvania. I am
a physicist.
You don't have that much traction,
which is limited by the grip of the four little footprints of tyre on the
road surface.
Click to expand...

That is why with twice as many tires being driven, you get twice the
acceleration. It is not quite twice, since the weight distribution is
not perfectly 50:50. It is more like an 80% increase.
You want to see four-wheel spin? Switch off the traction control.
Click to expand...

XC70 AWD doesn't have switchable Traction Control so I can't switch it
off. Without Traction Control it would only have three-wheel spin.
With Traction Control it has 4-wheel spin in glare ice.
Click to expand...
Click to expand...
 
James Sweet said:
Speaking of physics, an interesting fact is that the area of the footprints
of the tire have no effect on the traction, they tires could be as wide as
the car and they would still slip just as easily. It's all in the weight and
the frictional coefficient of the material.
Click to expand...

I was going to say that, because on dry hard surfaces it is true. In
physics class they use blocks on a table top where it is true. But with
a wet surface, the thickness of the layer of water changes as the area
and hence the pressure on the water changes. The coefficient of
friction is dynamic and varies with the thickness of the layer of water
and the roughness of the road surface and tire surface. The softness of
the rubber is another variable that changes the coefficient of friction
with pressure. So in principle, I agree, but there are second order
effects.
 
There are V70R's.... I seem them sitting at the Volvo dealer I goto, waiting
to be sold. They look SWEET, I'd love to buy one if I actually had the money
they want for one... I'd honestly have one over an S60R.
 
Stephen said:
I was going to say that, because on dry hard surfaces it is true. In
physics class they use blocks on a table top where it is true. But with
a wet surface, the thickness of the layer of water changes as the area
and hence the pressure on the water changes. The coefficient of
friction is dynamic and varies with the thickness of the layer of water
and the roughness of the road surface and tire surface. The softness of
the rubber is another variable that changes the coefficient of friction
with pressure. So in principle, I agree, but there are second order
effects.
Click to expand...

Even on dry pavement the coefficient of static friction (which is what
applies when the tire is rolling) also does not increase linearly with
pressure (despite what many secondary and college texts have to say on
the matter). A larger contact patch does in fact yield greater
friction, otherwise there would be no reason to worry about limiting
weight transfer during cornering and braking.

Just another Physicist checking in,
Bill
 
I was going to say that, because on dry hard surfaces it is true. In
physics class they use blocks on a table top where it is true. But with
a wet surface, the thickness of the layer of water changes as the area
and hence the pressure on the water changes. The coefficient of
friction is dynamic and varies with the thickness of the layer of water
and the roughness of the road surface and tire surface. The softness of
the rubber is another variable that changes the coefficient of friction
with pressure. So in principle, I agree, but there are second order
effects.
Click to expand...


There must be more to it than just a wet surface. Think of a Formula 1
or Cart/Indy race car - they must have those big fat rear tyres for
something, and it's certainly not aerodynamics. If it wasn't for the
rules limiting tyre width, the designers would have them even wider.
Wear rates are improved, but I don't think that is the primary reason.


--

TSH


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