Good explaination, Alex.
And in that statement lies the rub. You want to lift that right foot as little as possible.
LLoyd
My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “alex paterson” paterson@spro.net
To: e-type@jag-lovers.org
Sent: Tuesday, July 31, 2012 2:45:31 PM
Subject: Re: [E-Type] sway bars
An increase in diameter of the front bar will increase a
tendency for under steering which is normally corrected by
lifting off your right foot.
In reply to a message from LLoyd sent Tue 31 Jul 2012:
Where racing is concerned the standard Jag set up, used by
many other Brit companies as well, is not so good. I guess
they felt for the average driver it was better to have the
car correct itself when the foot came off.
Personally I like it more neutral so you can balance over
under steer on the throttle which gives you the opportunity
of 4 wheel drifting through corners something not so easy
with the stock arrangement.
Rear sway bar removal is strange on the E however one could
argue different tire technology on the S 3 cars however the
removal on the XJS is a real mystery.
Yes, this is the method to test the car to see if it is corectly ballanced.
LLoyd
My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “alex paterson” paterson@spro.net
To: e-type@jag-lovers.org
Sent: Wednesday, August 1, 2012 6:21:12 AM
Subject: Re: [E-Type] sway bars
Personally I like it more neutral so you can balance over
under steer on the throttle which gives you the opportunity
of 4 wheel drifting through corners something not so easy
with the stock arrangement.
In reply to a message from alex paterson sent Wed 1 Aug 2012:
There’s some folklore on the removal of the rear bar from
the XJS. It was there originally (and BTW it can be fitted
to XJ6 cars, which many have done). Then it disappeared,
then returned much later on some models.
I’ve heard from a couple of sources that Jaguar removed the
bar to improve the luxury ride quality. The supports below
the rear seat transmitted harshness into the cabin, which
was otherwise isolated from the suspension by the fore and
aft rubber mounts. And of course the sway bar removes part
of the I from the IRS (same at the front, of course).
I also heard that the rear suspension was redesigned so that
a sway bar was deemed unnecessary. I don’t know which
iteration of the coming/going of the factory bars this
pertains to.–
The original message included these comments:
Rear sway bar removal is strange on the E however one could
argue different tire technology on the S 3 cars however the
removal on the XJS is a real mystery.
–
Bob Wilkinson, 73 XJ6
Saint Louis, MO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from alex paterson sent Wed 1 Aug 2012:
‘‘Rear sway bar removal is strange on the E…’’ - There’s
nothing at all strange about it. The longer wheelbase and
heavier front end on the S3 could easily have changed the
handling balance enough to make the rear bar unnecessary to
achieve the balance the factory was after. This is
particularly logical for the S3, for which there was a very
deliberate emphasis on luxury than outright performance. A
rear sway bar would increase ride harshness (adding a sway
bar increases suspension stiffness in exactly the same
manner as increasing spring/T-bar rate). Deleting the rear
sway bar on the S3 would slightly increase the tendency to
under-steer, which is also considered desirable for cars
which are less performance-oriented. In any case, the
difference is likely small, as the rear bar on the 6-
cylinder cars is quite small in diameter. There are plenty
of cars out there with only front sway bars, so this is not
in any way unusual. Once again, adding a sway bar, is just
as likely to screw up handling, as to improve it, if not
done properly. The mere presence, or absence, of a sway bar
tells you absolutely NOTHING about how the car will actually
handle. And, which bars, and what diameters are ‘‘best’’ is
very much a function of how the car is to be driven. The
setup that gives best handling on the track will, in most
cases, be absolutely horrible on the street, and vice-versa.–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
… A
rear sway bar would increase ride harshness (adding a sway
bar increases suspension stiffness in exactly the same
manner as increasing spring/T-bar rate).
Interesting point here…I’ve always thought the front suspension
on my car was too harsh, almost jarring if you hit a decent sized
bump/hole. I have std sway bars/shocks/T-bars…so what is the
thinking on removing the front sway bar, only?On Wed, Aug 1, 2012 at 11:28 AM, Ray Livingston jagboy@pacbell.net wrote:
In reply to a message from Les Halls sent Wed 1 Aug 2012:
Les,
Remove the front bar, and you’ll have a car that handles
HORRIBLY! Get better shocks…–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Les, at low speeds (60 mph) that would give you tremendous oversteer. At high speeds it would give you bad oversteer.
I was just about to say that it is a lose-lose situation… but seeing now what you are getting at, I would say that if you drive like grandma, then you would have a more comfortable ride.
LLoyd
My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “Les Halls” jagaround@gmail.com
Interesting point here…I’ve always thought the front suspension
on my car was too harsh, almost jarring if you hit a decent sized
bump/hole. I have std sway bars/shocks/T-bars…so what is the
thinking on removing the front sway bar, only?
Les, at low speeds (60 mph) that would give you tremendous oversteer. At high speeds it would give you bad >oversteer.
I was just about to say that it is a lose-lose situation… but seeing now what you are getting at, I would say that if >you drive like grandma, then you would have a more comfortable ride.
In reply to a message from Les Halls sent Wed 1 Aug 2012:
Les,
Remove the front bar, and you’ll have a car that handles
HORRIBLY! Get better shocks…
Right…I just wondered because it never feels like the suspension
has any chance of travelling through its full stroke.
I recall the F1 cars of the 70’s…long stroke relatively soft
suspension. Very different to f1 cars today. However those 70’s
machines still performed extremely well. Now I know it’s not correct
comparing a F1 car to a street car but the theory surely remains the
same…main problem I guess is that the E has so much more
“high” weight having to be thrown around.
Anyway, thought I’d ask…:-)On Wed, Aug 1, 2012 at 12:02 PM, Ray Livingston jagboy@pacbell.net wrote:
Ehhh??? What that you say, ya young whipersnapper. I can’t hear you.
grandpa LLoyd
My driveway is long enough that you can appreciate the conflict between the desire for privacy and the terror of being completely lost .----- Original Message -----
From: “Les Halls” jagaround@gmail.com
To: e-type@jag-lovers.org
Sent: Wednesday, August 1, 2012 9:32:18 AM
Subject: Re: [E-Type] sway bars
In reply to a message from Les Halls sent Wed 1 Aug 2012:
Roll stiffness and vertical stiffness are set independently
by design. Alfas are similar to the older F1 cars–soft
springs, a lot of damping, and a big anti-roll bar. If you
wish to add a lot of roll stiffness, consider softening the
springs or torsion bar (while maintaining ride height).
More roll stiffness than the factory at either end results
in flatter cornering, which gives the illusion of control
and feels good. Actual handling is usually reduced, though,
because there is more weight transfer in turns and
consequently less total grip.
Cars with transverse springs (like Corvettes) are really
cool because, using only the setup of the center pivots, you
can adjust roll and vertical stiffness separately. In fact
you can reduce roll stiffness to zero–impossible with other
suspensions.–
The original message included these comments:
Right…I just wondered because it never feels like the suspension
has any chance of travelling through its full stroke.
I recall the F1 cars of the 70’s…long stroke relatively soft
suspension. Very different to f1 cars today. However those 70’s
machines still performed extremely well. Now I know it’s not correct
–
Bob Wilkinson, 73 XJ6
Saint Louis, MO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Roll stiffness and vertical stiffness are set independently
by design. Alfas are similar to the older F1 cars–soft
springs, a lot of damping, and a big anti-roll bar. If you
wish to add a lot of roll stiffness, consider softening the
springs or torsion bar (while maintaining ride height).
More roll stiffness than the factory at either end results
in flatter cornering, which gives the illusion of control
and feels good. Actual handling is usually reduced, though,
because there is more weight transfer in turns and
consequently less total grip.
Makes sense to me Robert, but, goes against the grain of modern
thinking as with my 911, and also with modern F1 where suspension is
very firm and roll is almost zero. Also true of modern sports car
racing where there’s almost zero roll even under the most arduous
cornering pressures.
However, personally, if think I prefer the Alfa setup you describe.
Don’t know how get the correct ride height with softer t-bars, without
going through all kinds of experimenting with different
sets…sound very expensive.On Wed, Aug 1, 2012 at 2:18 PM, Robert Wilkinson wilk@wustl.edu wrote:
In reply to a message from Les Halls sent Wed 1 Aug 2012:
I’m afraid you’re out of my realm with that ‘‘modern
thinking,’’ Les. Like those 911’s I see around…I guess I
missed their introduction.
Anyway, the 356s of my era (don’t see why they had to
replace them) are a good example of the chassis tuning I’m
talking about. To reduce oversteer, they lightened up the
rear torsion bars–which gave less rear roll stiffness but
also less rear vertical stiffness. They got back the latter
by fitting a transverse spring that was freely pivoted at
its center. This contributed vertical stiffness but added
no roll stiffness. Weight transfer at the rear during
cornering was reduced, reducing oversteer. This in effect
‘‘transferred’’ the cornering weight transfer to the front,
and here they beefed up the anti-roll bar.
The lack of roll in many modern cars is amazing, but roll is
not the same as roll stiffness. Less roll without adding
roll stiffness comes with lower roll centers (911 vs 356 is
a good example) and lower center of gravity. These factors
reduce the torques on the body that make it want to roll and
transfer weight in the first place.
I think the F1 cars are a special case. They have to stay a
pretty fixed distance from the track or else their
downforce changes, with catastrophic effects. Rules don’t
allow any computer stuff (conventional springs only) so the
suspension has to be pretty stiff.–
The original message included these comments:
Makes sense to me Robert, but, goes against the grain of modern
thinking as with my 911, and also with modern F1 where suspension is
very firm and roll is almost zero. Also true of modern sports car
–
Bob Wilkinson, 73 XJ6
Saint Louis, MO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Les Halls sent Wed 1 Aug 2012:
Suspension tuning is a complicated subject and depends on
the mechanical arrangement in your car fitting with your own
driving style and on what surface you drive.
Colin Chapman was a great proponent of softer springing and
reasonable damping with great results.
If you find the front of your E hard the first thing to do
is buy a set of adjustable front shocks like Spax which can
be click adjusted without removal.
set the click mid way and adjust both up or down until you
get the ride you want.
In reply to a message from Robert Wilkinson sent Wed 1 Aug 2012:
That condition is only applicable to cars with swing arms rear
suspensions, Robert: Formula Vees use zero roll with great effect,
but it will NOT work on vehicles like our E Types.–
The original message included these comments:
talking about. To reduce oversteer, they lightened up the
rear torsion bars–which gave less rear roll stiffness but
also less rear vertical stiffness. They got back the latter
by fitting a transverse spring that was freely pivoted at
its center. This contributed vertical stiffness but added
no roll stiffness. Weight transfer at the rear during
cornering was reduced, reducing oversteer. This in effect
‘‘transferred’’ the cornering weight transfer to the front,
and here they beefed up the anti-roll bar.
–
Paul Wigton, steward to a '60 DKW 1000 SP, Tweety, '63 FHC!
Keenesburg, CO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Wiggles sent Thu 2 Aug 2012:
Agreed 100%, Paul–and happy to hear your comment on the list.
I was actually trying to make a more general point. Car
owners add or beef up roll bars but don’t usually optimize
the vertical stiffness (coil springs or torsion bars) at the
same time. But factory changes usually involve both.
As you mention, swing-axle cars like VW (and Formula Vee),
356, Corvair, some Mercedes can benefit from zero rear roll
stiffness (with lots of front roll stiffness). Unless you
eliminate coil or torsion springs altogether (substituting a
pivoted transverse spring) the only way to do this is to fit
a rear sway bar that subtracts, rather than adds, roll
stiffness. That’s a popular method in Formula Vee–the
‘‘z-bars’’ are connected so that when one wheel goes up, the
other is forced down. They resist vertical movement of both
wheels together, but offer no resistance if the body rolls.
None of the above applies to purple cars, BTW :-)–
The original message included these comments:
That condition is only applicable to cars with swing arms rear
suspensions, Robert: Formula Vees use zero roll with great effect,
but it will NOT work on vehicles like our E Types.
–
Bob Wilkinson, 73 XJ6
Saint Louis, MO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–