They both are transverse mounted leaf springs.
The earlier spring is a fixed perch, bolted directly to the differential.
Since the differential is bolted to the frame, you can think of this type of
spring as being bolted directly to the frame. As a result of being bolted to
the frame, this spring will resist body roll.
A true swing spring on the other hand, is mounted on a pivot at the frame
mount. As such, it cannot resist body roll. It just rotates about the pivot.
It will resist total weight loading only. A vehicle with a true swing spring
in the rear (like many Formula V's) will have all roll resistance performed by
the front suspension. This makes jacking the front end of one off the ground
somewhat interesting as the vehicle will flop over once both front wheels are
off the ground.
The late Spitfires do not have a true swing spring. They have a hybrid
combination. You may find it easiest to think of the car as having to separate
rear springs.
The first is a fixed spring. It happens to be the lower leaf of the entire
spring pack. It resists body roll. Since it is just one leaf, any frailties
with this leaf become very evident and pronounced. The amount of body roll
resistance is also rather minimal due to it being just a single leaf.
The second is the true swing spring. It happens to be the rest of the spring
pack. This pivots freely about the pin in the mounting box. There is zero
roll resistance from this spring...technically. Due to various bindings, there
is some roll resistance.
I know in a previous post I made it sound as if there is no way a swing spring
can affect lean. In a perfect world, that would be true. But if the swing
spring is hanging up on the pivot, it will contribute to lean. And in the case
of the Spitfire, the lower leaf fatiguing can contribute since it's not a swing
spring. As can binding between the lower leaf and the swinging spring pack
right above it.
>>> "John T. Blair" <jblair1948@COX.NET> 04/15/04 06:13PM >>>
I keep hearing about the differences in the rear ends of the 2 Spits. But
when I look at the shop manuals for the 2 cars, I don't really see any
difference. So what am I missing, and what's the difference between
the 2 system?
-----------------------------------------------------
The information contained in this communication may be confidential, is
intended only for the use of the recipient named above, and may be legally
privileged.
If the reader of this message is not the intended recipient, you are hereby
notified that any dissemination, distribution, or copying of this
communication, or any of its contents, is strictly prohibited.
If you have received this communication in error, please re-send this
communication to the sender and delete the original message and any copy of it
from your computer system. Thank you.
-----------------------------------------------------
<<<<GWIASIG 0.07>>>>
|