Horsepower cuts embarass Asians

Not all were in integral. My old 1985 midsized Ford LTD had struts but
the shocks were separate. A very easy change of either item.

JT

 

A limited slip differential and a locking differential are not the same
thing. A limited slip differential does lose some energy because kinetic
energy is converted to heat. With a locked differential there is zero
slippage and therefore zero energy loss when locked..

You were close but not quite correct in your example of a locked
differential with both wheels turning together where one wheel has traction
and the other does not.. In that example, it is the wheel/tire that is
scrubbing the energy, not the differential.

 

A limited slip differential and a locking differential are not the same
thing. A limited slip differential does lose some energy because kinetic
energy is converted to heat. With a locked differential there is zero
slippage and therefore zero energy loss when locked..

You were close but not quite correct in your example of a locked
differential with both wheels turning together where one wheel has traction
and the other does not.. In that example, it is the wheel/tire that is
scrubbing the energy, not the differential.

 

Yes... but...

An open diff will let your power get wasted onto the spinning wheel.

A locked diff will make sure both spin at the same speed, so the power
is distributed in proportion to the traction. This is a bit interesting
in corners where you want the outside wheel to go farther (and hence
faster) than the inside one.

An LSD will transfer some of the energy from a spinning wheel back to
the gripping one - but it wastes some too. It does however let you go
round corners without eating tyres.

They do "lose energy big time" but it's worth it as otherwise that
energy, and more, would be wasted elsewhere.

Andy

 

Yes... but...

An open diff will let your power get wasted onto the spinning wheel.

A locked diff will make sure both spin at the same speed, so the power
is distributed in proportion to the traction. This is a bit interesting
in corners where you want the outside wheel to go farther (and hence
faster) than the inside one.

An LSD will transfer some of the energy from a spinning wheel back to
the gripping one - but it wastes some too. It does however let you go
round corners without eating tyres.

They do "lose energy big time" but it's worth it as otherwise that
energy, and more, would be wasted elsewhere.

Andy

 

If a double wishbone suspension costs the automaker $50 more than a strut
suspension, do you think the automaker would put put double wishbones in all
cars and not pass that cost on to the consumers?

I meant no insult, just an observation, and I apologize. My intent is to
share the experience and knowledge I gained while working for an automaker
and correct people's misconceptions about how cars work. The more people
know about their cars, the more realistic their expectrations of the car's
performance and the more satisfied they weill be with their car.

When I said "know instinctively," I meant it from the point of view of a
professional who spends all day working on and studying a subject and knows
something without giving it consccicous thought. For example, a carpenter
whose specialty is framing houses will know instinctively when he looks at a
new house being built whether it is framed correctly or not.

You mentioned that maintaining tire contact is not as important in an
environment where traction is poor, and someone with an auto engineering
background or who works with cars day in and day out would know without
conscious thought that this statement was incorrect.

I am always willing to listen and learn something new and I think the
regulars in alt.autos.toyota will testify that I will admit when someone
points out an error on my part. As I mentioned earlier, I meant no insult
by the "instinct" comment - perhaps "second nature" or "knowing without
conscious thought" would have been a better choice of terms.

I spent some time working for a fairly large auto maker and have had the
benefit of working with and learning from automotive engineers, designers,
and the technicians who had to work on them our in the real world. This
auto maker is the most profitable auto maker in the world and so I feel that
it is safe to That experience and their explanations were a huge help when I
had to look at problem vehicles that the dealerships could not fix.

What am I missing by a country mile?

 

If a double wishbone suspension costs the automaker $50 more than a strut
suspension, do you think the automaker would put put double wishbones in all
cars and not pass that cost on to the consumers?

I meant no insult, just an observation, and I apologize. My intent is to
share the experience and knowledge I gained while working for an automaker
and correct people's misconceptions about how cars work. The more people
know about their cars, the more realistic their expectrations of the car's
performance and the more satisfied they weill be with their car.

When I said "know instinctively," I meant it from the point of view of a
professional who spends all day working on and studying a subject and knows
something without giving it consccicous thought. For example, a carpenter
whose specialty is framing houses will know instinctively when he looks at a
new house being built whether it is framed correctly or not.

You mentioned that maintaining tire contact is not as important in an
environment where traction is poor, and someone with an auto engineering
background or who works with cars day in and day out would know without
conscious thought that this statement was incorrect.

I am always willing to listen and learn something new and I think the
regulars in alt.autos.toyota will testify that I will admit when someone
points out an error on my part. As I mentioned earlier, I meant no insult
by the "instinct" comment - perhaps "second nature" or "knowing without
conscious thought" would have been a better choice of terms.

I spent some time working for a fairly large auto maker and have had the
benefit of working with and learning from automotive engineers, designers,
and the technicians who had to work on them our in the real world. This
auto maker is the most profitable auto maker in the world and so I feel that
it is safe to That experience and their explanations were a huge help when I
had to look at problem vehicles that the dealerships could not fix.

What am I missing by a country mile?

 

Generally they are, and the answer to your question is no. Have you looked
at your front wheels as I suggested?

mike

 

yes... but... the quaife lsd, the one up thread, doesn't. and it's open.

no, if they're locked, they're not in proportion to traction. they're
just locked, so the wheel that's still scrubbing is wasting energy.

and that's why these diffs are called "limited slip", not "locked".

with low traction, that's pretty much irrelevant!

lsd's are a great idea. some of the fancy schmancy clutched ones use
transfer fluids that increase viscosity as shear rate increases, but the
price is efficiency.

 

yes... but... the quaife lsd, the one up thread, doesn't. and it's open.

no, if they're locked, they're not in proportion to traction. they're
just locked, so the wheel that's still scrubbing is wasting energy.

and that's why these diffs are called "limited slip", not "locked".

with low traction, that's pretty much irrelevant!

lsd's are a great idea. some of the fancy schmancy clutched ones use
transfer fluids that increase viscosity as shear rate increases, but the
price is efficiency.

 

not agreed. the tire that's still slipping is still slipping. that's
loss. if you mean loss /within/ the diff, that's true, but it's no good
worrying about that if you're losing ground on every turn.

see above. i've been talking about energy transferred to the road all
along.

 

not agreed. the tire that's still slipping is still slipping. that's
loss. if you mean loss /within/ the diff, that's true, but it's no good
worrying about that if you're losing ground on every turn.

see above. i've been talking about energy transferred to the road all
along.

 

so what's the price difference between the camry and accord?

according to edmunds, the base [wishbone] accord is $18225, the [strut]
camry is $18270.

i therefore re-state, car manufacturers do /not/ sell on a "cost plus"
basis, so the price of parts is irrelevant.

ok, no problem.

i disagree. go to any parking lot where there's a big-tired mercedes or
bmw that's on full lock. the "outside" tire has the full contact patch
flat against the ground. the "inside" tire however is riding up on one
edge because the camber is all wrong. this is an "acceptable" situation
as, in practice, hardly anyone drives these cars hard enough for it to
be a real issue. with 10" [or whatever] of rubber on the side of the
car making the most load, who notices? /but/, when you're driving at
10/10th's, that extra little bit of rubber on the /inside/ tire that's
more correctly positioned can get you through the corner faster than the
other guy. my no means are hondas the most powerful cars on the road,
but they sure do hang well with the big boys as soon as there's a bend.

with mcpherson it's the "approximation" that's required for every
element of geometry that makes it less than perfect. but it's ok for
sedans, cheap, comfy and doesn't roll much. wishbones are better on
road where there's greater steering precision possible. disadvantages
of wishbones are cost, a little comfort, and the need to address roll
since the greater degree of freedom the body has within the system
leaves it free to do so. i'd draw a pic, but in ascii it would suck.
also consider the fact that mcpherson first came out when bias ply tires
were all you could get - again, no need to be precise there!

 

so what's the price difference between the camry and accord?

according to edmunds, the base [wishbone] accord is $18225, the [strut]
camry is $18270.

i therefore re-state, car manufacturers do /not/ sell on a "cost plus"
basis, so the price of parts is irrelevant.

ok, no problem.

i disagree. go to any parking lot where there's a big-tired mercedes or
bmw that's on full lock. the "outside" tire has the full contact patch
flat against the ground. the "inside" tire however is riding up on one
edge because the camber is all wrong. this is an "acceptable" situation
as, in practice, hardly anyone drives these cars hard enough for it to
be a real issue. with 10" [or whatever] of rubber on the side of the
car making the most load, who notices? /but/, when you're driving at
10/10th's, that extra little bit of rubber on the /inside/ tire that's
more correctly positioned can get you through the corner faster than the
other guy. my no means are hondas the most powerful cars on the road,
but they sure do hang well with the big boys as soon as there's a bend.

with mcpherson it's the "approximation" that's required for every
element of geometry that makes it less than perfect. but it's ok for
sedans, cheap, comfy and doesn't roll much. wishbones are better on
road where there's greater steering precision possible. disadvantages
of wishbones are cost, a little comfort, and the need to address roll
since the greater degree of freedom the body has within the system
leaves it free to do so. i'd draw a pic, but in ascii it would suck.
also consider the fact that mcpherson first came out when bias ply tires
were all you could get - again, no need to be precise there!

 

When you work with a bunch of anal retentive engineers like I used to, it
rubbs off. They would say that since the original discussion was
differential efficiency, then the same would have to be true of a locked
differential, with a foot note describing the enery loss from the tires.

We were talking about similar but different things. The nit picker in me
would say that if we were discussing energy transfer to the road, then the
words "energy transfer to the road" should have been included at the
beginning of the discussion as opposed to differential energy. Since you
were talking about energy transfer to the road, then you were correct,
however, I still believe that your characterization of the Quaife diff as
"open" is still incorrect because "open" does not mean the lack of clutches,
silicone fluid, locking sleeves, etc. - I guess Quaife and I will have to
agree to disagree with you there. ;-)

 

When you work with a bunch of anal retentive engineers like I used to, it
rubbs off. They would say that since the original discussion was
differential efficiency, then the same would have to be true of a locked
differential, with a foot note describing the enery loss from the tires.

We were talking about similar but different things. The nit picker in me
would say that if we were discussing energy transfer to the road, then the
words "energy transfer to the road" should have been included at the
beginning of the discussion as opposed to differential energy. Since you
were talking about energy transfer to the road, then you were correct,
however, I still believe that your characterization of the Quaife diff as
"open" is still incorrect because "open" does not mean the lack of clutches,
silicone fluid, locking sleeves, etc. - I guess Quaife and I will have to
agree to disagree with you there. ;-)

 

Your comparison of the Camry and Accord would be valid if the suspension
type were the only differences between the cars. Toyota and Honda have
different cost structures with labor, raw material, plant and corporate
overhead, advertising, travel and entertainment, etc. as well as different
content, distributor markup, and dealer markup. I am not aware of any
vehicle where a strut and a different type of front suspension is availble
so it is not easy to make a comparison unless you have a background in how
automakers price their vehicles. Trucks offer different front suspensions
for RWD and 4WD versions and for different capacities. The Japan market
Estima Van had an independent rear suspension and the U.S. Previa van had a
live axle, but neither rear suspensions were strut type.

Your point is valid in that "cost plus" is not the sole determing factor in
vehicle pricing, however, the automaker's cost to produce a vehicle is the
starting point in determineing what the final MSRP will be. Market
competition plays a big factor as well as market demand. I susect that
we're saying the same thing differently.

The effect you're describing about camber changes is not caused by the type
of suspension, i.e., strut vs. double wishbone. It is caused by lots of
positive caster, like 10 or more degrees, and you will see the same effect
whether the car has a strut of wishbone suspension if there is lots of
positive caster. Another effect of vehicles with lots of positive caster is
that you will see the front end of the vehicle actually dip when the wheel
is turned full lock. This effect is magnified somewhat by the large wheels
and tires. Automakers will design lots of positive caster to provide
straighter tracking, and the tradeoff is slightly less responsive turning.

Aaah! What I'm getting from what you're describing is different from what I
got from your other posts. In your other posts, I got that you were saying
that strut suspensions offered superior handling to wishbones. What you are
conveying here is much more accurate than your previous posts - we're on the
same page now (we probably were before but on different frequencies).

 

Your comparison of the Camry and Accord would be valid if the suspension
type were the only differences between the cars. Toyota and Honda have
different cost structures with labor, raw material, plant and corporate
overhead, advertising, travel and entertainment, etc. as well as different
content, distributor markup, and dealer markup. I am not aware of any
vehicle where a strut and a different type of front suspension is availble
so it is not easy to make a comparison unless you have a background in how
automakers price their vehicles. Trucks offer different front suspensions
for RWD and 4WD versions and for different capacities. The Japan market
Estima Van had an independent rear suspension and the U.S. Previa van had a
live axle, but neither rear suspensions were strut type.

Your point is valid in that "cost plus" is not the sole determing factor in
vehicle pricing, however, the automaker's cost to produce a vehicle is the
starting point in determineing what the final MSRP will be. Market
competition plays a big factor as well as market demand. I susect that
we're saying the same thing differently.

The effect you're describing about camber changes is not caused by the type
of suspension, i.e., strut vs. double wishbone. It is caused by lots of
positive caster, like 10 or more degrees, and you will see the same effect
whether the car has a strut of wishbone suspension if there is lots of
positive caster. Another effect of vehicles with lots of positive caster is
that you will see the front end of the vehicle actually dip when the wheel
is turned full lock. This effect is magnified somewhat by the large wheels
and tires. Automakers will design lots of positive caster to provide
straighter tracking, and the tradeoff is slightly less responsive turning.

Aaah! What I'm getting from what you're describing is different from what I
got from your other posts. In your other posts, I got that you were saying
that strut suspensions offered superior handling to wishbones. What you are
conveying here is much more accurate than your previous posts - we're on the
same page now (we probably were before but on different frequencies).

 

Struts are the wave of the future. Not only are struts less expensive,
but struts are also more space efficient than double-wishbone
suspensions. Carmakers can design a roomier cabin and more capacious
trunk for a car when using struts.


A sign that struts have come along is that the new BMW 3 series uses
them. If they're good enought for "the ultimate driving machine" then
they are quit good now. Take note on how the 3 series is now a much
roomier car and it is still quite a driving machine.

CD

 

Struts are the wave of the future. Not only are struts less expensive,
but struts are also more space efficient than double-wishbone
suspensions. Carmakers can design a roomier cabin and more capacious
trunk for a car when using struts.


A sign that struts have come along is that the new BMW 3 series uses
them. If they're good enought for "the ultimate driving machine" then
they are quit good now. Take note on how the 3 series is now a much
roomier car and it is still quite a driving machine.

CD