Page 21
The Saab 99 has extremely good
directional stability. It is also slightly
understeered.
When cornering it takes a slightly wider
line than that exactly corresponding
to the movement of the wheel. The turn-
ing radius increases with the speed
unless the driver compensates for this by
turning more on the wheel. This charac-
teristic, which is due to the weight
distribution of the car, provides good
directional stability and reduces the risk
of rear-end break-away. It also reduces
steering wheel effort under practically
all driving conditions. Steering is
rack and pinion type, precise in action
and with a minimum of lost motion.
The wheels respond accurately to every
movement of the steering wheel. The
tie rods are located so that the angle of
the front wheel is practically unaffected
when the wheels move up and down
on their springs, As a result, the driver
does not have to make corrections
with the wheel when the car is driven
over uneven road surfaces. Steering
geometry is also designed to prevent
changes in throttle openings from no-
ticebly affecting the steering. Turning
circle is 34 ft and the number of
steering wheel turns lock to lock, is 3.7.
The steering box is located at the rear
of the engine compartment, well pro-
tected by the engine: In consequence, a
very severe impact would be required
to force it back and displace the steering
column, This latter nevertheless con-
sists of two sections connected by a
universal joint so that in the event of
such an impact occurring it will fold in
the middle. It is also telescopic and
designed to collaps (Fig. D) if subjected
to axial loads above a certain limit.
At the same time its attachment to the
carbody will give way.
The steering wheel has safety padding
over the spokes and the dished hub.
Page 22
Brakes.
Both front and rear wheels are fitted
with disc brakes, Since these have no
self-servo action, braking is smooth and
braking effort proportional to pedal
pressure. All four disc brakes are self-
adjusting and equipped with highly heat-
resistant pads — which are practically
fade-free even after repeated heavy
braking
When the brake pads are worn to such
an extent that replacement is necessary,
the driver is made aware of this by
higher pedal pressures being required.
This advance warning is given before
the brake pads are worn down so far that
they may damage the discs.
It goes practically without saying that
the braking system features dual in-
dependent hydraulic circuits: Saab intro-
duced the twin-circuit system as early
as 1963 and can consequently be counted
among the pioneers of this safety
feature which is now fairly common
But the Saab system is still unique. Con-
trary to usual practice, it is not divided
so that one circuit serves the front
brakes and the other circuit the
rear brakes, Instead, the braking circuits
of the Saab are arranged diagonally
so that one front wheel and the
diagonally opposite rear wheel are served
by one circuit and the other two wheels
by the other circuit (Fig. G_ 1). In the
event of failure in one circuit there is still
always as much as 50 % of normal
braking power available. Should it
be necessary to use two-wheel braking
on slippery or icy roads, it is advan-
tageous to have one front wheel and
one rear wheel that cannot lock up but
help to keep the car on course instead.
The master cylinder actuates both
circuits simultaneously but independently
of each other. The risk of a fault occur-
ring in the brake lines has been reduced
to a minimum — they are located in such
a way as to be protected from mechanical
and chemical damage, inside the car
on the sill member of one side (Fig. A)
underneath a moulding which permits
the circulation of air. A red warning
lamp in the combination instrument (the
lefthand circular instrument on the
dashboard) lights up when brake pedal
travel is excessive for any reason
if a brake line develops a leak, for in-
stance, This lamp also doubles as a hand-
brake warning light (Fig. B).
The front wheel brake cylinders are of
greater diameter than those of the rear
wheels, As a result, slightly more than
80 % of braking power is applied to the
front wheels. The rear wheels — which
carry a lighter load — show no tendency
to lock up too early under heavy brak-
ing.
The braking system is equipped with
a vacuum power assist which substantially
reduces the pedal pressure required for
a given braking effect (Fig, F).
The handbrake acts mechanically on
the front wheels. Special brake drums at
the hubs of the brake discs are
actuated by well-protected cables
operated by the brake lever, conveniently
placed between the front seats
(Fig. D, E), Using the handbrake, a
braking effect of up to about 50 % of
the normal braking system can be
attained, Asa result, the handbrake
makes an effective emergency brake.
And since it acts on the front wheels
while the rear wheels continue to roll
freely, there is no danger of the car
running off course and skidding side-
ways,
Page 24
Modern and tough power plant
Saab 99 has a watercooled, four-
cylinder straight engine with an over-
head camshaft. The engine block is
manufactured of special cast iron and _
the cylinder head of aluminum alloy.
The crankshaft and camshaft are
mounted in five bearings.
The cylinder block slopes at an angle
of 45° to the right (Fig, A) and the
engine js located so that it has the end
with the clutch turned forwards and the
driving mechanism for the camshaft
nearest the bulkhead. The cylinders are
numbered from back to front,
The engine cooling is of cross flow type
and it has a closed crankcase ventilation.
The water pump, oil pump and distri-
butor are operated via a special idler
shaft. The gearbox is located under the
engine and is an integral part of it.
Two different versions
The new Swedish-built 2-liter engine
is offered in the E and C versions, i.e.
with electroni¢ fuel injection or carbu-
retor. The C engine develops a maximum
net horsepower of 95 hp SAE and the
E engine develops a net of 110 hp SAE.
Service engine with good hard pull
characteristics
The torque curve of the carburetor
engine is above the mark for 100 lb ft
between 1700 and 4800 rev/min,
The max. mark, 116 Ib ft is reached at
3500 revs, This implies that the engine
has yery good hard pull characteristics
and that there is no need to shift gears
all the time.
The fuel-injected engine is even more
powerful. It produces a full 123 tb ft
at 3700 rev/min. The torque curves
for both engines are very flat, remain-
ing at a high level within a broad
range of rev/min,
24
The engine is not of a highly tuned and
sensitive type, but instead a reliable and
durable service engine, shown by the
fact that the specific output is moderate.
It varies from about 47 to 55 hp per
liter of cylinder volume, The E engine
boasts the highest figure.
Because the inlet and exhaust main-
folds are located on cach side of the
cylinder head it has been possible to
make them sufficiently large and to shape
them in a way that is more favorable as
regards the performance with maxi-
mum at low revolutions and free “breath-
ing” at high revs,
Short stroke, vibrationsless, ready
to respond in reys.
With a stroke of 3.07 in. the engine
has an adequately short stroke so that
it will withstand high revolutions
without the average piston speed and
mass forces attaining unsuitably high
values. However, the short stroke is not
overemphasized, so that the hard pull
deteriorates,
The crankshaft itself is made of forged
steel and has ground bearing surfaces;
is dynamically balanced and kept within
narrow dimensional lolerances. The
connecting rod bearings and the five
main bearings have such large diameters
that they “overlap” one another to a
considerable extent, which in turn
renders the crankshaft stiff and vibra-
tion-free.
Overhead camshaft, long intervals
between valve adjustments
It will be noticed by the valve mechanism
that the engine is made to work smoothly
and free from noise. As the camshaft
is overhead, i.e. located in the cylinder
head, the valve depressors are activated
directly, without pushrods and rocker
arms, which would increase the
number of moving parts and also
create rattle, One major advantage
with the valve mechanism is that
it allows for longer intervals between
the regular valve adjustments.
The cylinder head can be dismantled
and reassembled without the valve
clearance being affected. The camshaft
is driven by a double chain.
Adapted to the environment
The 99 engine meets highly placed
requirements with regard to what is
usually termed as being favorable to
environmental conditions. It has low
noise level and an unusually high degree
of purification of the exhaust fumes.
Both the carbureted and the fuel-injected
version should be driven on low-octane
lead-free gasoline (94 octane).
The crankcase ventilation is made effec-
tive by air being taken in through the
air filter and via a flame guard and the
engine oil filler pipe and led on to the
crankcase, from where it flows upwards
and through a hose from the camshaft
cover js supplied to the intake mani-
fold. The ventilation which is conse- w
quently completed is regulated by a Smit
valve close to the intake manifold. The
exhaust pipe runs through a tunne!
beneath the floor of the car and is
thus well protected against damages
when the vehicle is being driven on rough
roads,
Because the metal plating in the rear
muffler and pipe is made of aluminum,
the exhaust system has great durability,
Easy to start
Tt was decided from the beginning that
the engine should be easy to start. The
requirement was absolutely necessary
and, not only concerned fine summer
days. Even when the vehicle has o
been standing parked outside in exceed-
ingly cold weather conditions, it must
be possible to start it up without any
difficulty. Impartial and comparative
tests have also proven that the
Saab 99 models up to and including the
1972 models are, in this respect, among
the best cars made, And there is not-
hing to say that the 1973 models should
not maintain this high standard of
quality.
.
Low fuel consumtion
Saab 99 has made a name for itself
because of low fuel consumption. The
new 2-liter engine also permits very
economic operation. One reason for this
Page 25
is low air resistance of the car, and
another is the efficiency of the engine.
A further factor is that the engine does
not require high-test gasoline. Regardless
of whether it is carbureted or fuel-in-
jected, it should be driven on 94 octane
gasoline.
Air preheating, horizontal carburetor
The air cleaner has a paper filter and
serves both as intake muffler and cleaner
for the intake air. The carburetor en-
gine air intake is provided with a butter-
fly valve, adjustable in two positions:
Summer” and "Winter. When the
Qpitside temperature is constantly lower
than +40°F the butterfly valve
should be put in ’Winter’’-position,
whereby the air is preheated by being
led inside the covering around the
(Qhaust pipe. The carburetor is a hori-
zontal flow type made by Zenith-Strom-
berg. It has a self-centering fuel needle
and Jacks a special idling system. In-
stead of a conventional type choke there
is a separate emulsion system for cold
starts and quick idling. The carburetor
has designation 175 CD-2S, which,
among other things, means that it has
a diameter of 1 34” and functions
with constant under-pressure in the
nozzle. The fuel pump is mechanical and
is operated by a cam on the special
idler shaft, which also operates the oil
pump, water pump and distributor.
_, Electronic “brain” knows best
phe fuel pump on the E-engine is elec-
tric and together with a filter located
behind the fuel tank. The filter is easily
accessible for cleaning or replacing.
The fuel system of the E-engine consists
0 principle of four injection valves,
which are connected to a fuel line in
which the pressure aided by a governor is
maintained at a determined level. A
start valve is also included, which at
low temperatures (below approx +40°F)
injects additional fuel into the air-
collecting pipe when the starter motor
is turned on. The electronic control
device (Fig. B) is located on the left
wheel housing where it receives informa-
tion from the transmitter on the engine
about RPM and loading conditions and
Page 26
through electrical messages controls the
opening time of the injection valves.
When warming up the engine, on ac-
celeration and at full load, a very ac-
curate amount of fuel must be injected,
On the other hand, when braking with
the engine, the injection must be reduced
or completely interrupted, These mea-
sures are effected by the “electronic
brain” which each moment knows
what is required. With such a system,
the engine always receives the right
amount of fuel, which gives nearly
complete combustion, high top output
and very clean exhaust fumes.
Effective cooling system, short warming
up time, electric-operated fan
The cooling system shall be responsible
for making sure that the engine keeps
the right operating temperature under
all load conditions, regardless of what
the weather is,
For this task a radiator is required,
which becomes effective when it is
needed, but does not divert the heat
unnecessarily,
For that reason Saab 99 has a
cross flow type radiator (Fig. D) and a
reliable thermostat, There is also
a fan which only turns on when the
coolant temperature tends to get too
high, such as during bumper-to-bumper
driving in traffic jams. During normal
driving, the fan usually remains sta-
tionary so it does not steal power un-
necessarily and does not cause needless
noise. The on-off switch is controlled
by a thermostat.
The water pump has large capacity
and leads the coolant at considerable
speed past the hottest parts of the cy-
linder block. The parts of the engine
that need cooling most, thus
receive the most intensive cooling; Water
jacket completely surround each cylin-
der. The coling system is pressurized at
the proper working temperature and is
provided with an expansion tank which
handles excess fluid.
Since the cooling system as a whole
including the fresh air heater, does not
contain more than 10 U.S. quarts
and the thermostat keeps the cooler
intake closed until the engine
has attained the right working tempera-
ture, the period of warming up is
unusually short. This is noticed indirectly
by the fact that after the car has been
standing awhile and becomes thoroughly
cold, warm air begins to enter into
the cabin within a few minutes after
starting the engine, When the car
leaves the factory the cooling system
is filled with anti-freeze.
Lubrication and oil filter
The engine has a pressure lubrication
system and is equipped with an oil filter
of full flow type. Each connecting rod
bearing has a separate oil-way through
the crankshaft from the next main
bearing in front. The quantity of oil
must not be less than 2.6 U.S. quarts
or more than 3.7 U.S, quarts. The
oil and filter should be replaced every
6,000 miles or at least twice a year.
The oil filter is of the "throw-avaw”
type.
Ample yolts, amps and watts
Saab 99 has a well dimensioned and
functionally safe electrical system.
The voltage is 12 V and the capacity of
the battery 60 Ah, The starter motor
is | hp. The maximum charging current
of the alternator in cars with carburetor
engine is 35 A and in the E-models a full
§5 A. The alternator charges already
at low engine speeds,
The electrical wires are color coded in
order to be easily distinguishable.
The connections consist of non-soldered
conductor joints. The ignition leads
are disturbance ¢liminated. The electrical
system is protected by 12—% A fuses,
of which one is intended for extra
equipment, They are easily accessible
in a box on top of the left-side wheel
housing. It is clearly indicated to what
part of the system each fuse belongs.
Gearbox under the engine
The engine is integrally-built with the
clutch, gearbox and the differential
to form one complete compact unit,
which is a saving in both weight and
space, (No encroachment in the pas-
senger compartment, no rear drive
shaft, no heavy power transmission as-
semblies at the rear.) The power is
gearbox and differential located under
the engine. The drive joints are perma-
nently lubricated and normally need
no maintenance, Cars with manual gear-
boxes have hydraulically-operated, single
dry disc clutch made by Borg & Beck,
The primary gear consists of pinions.
The clutch which is placed at the front
of the engine is effectively cooled.
This contributes towards long service life
for the dise lining, and service
work on the clutch is facilitated,
‘The gearbox, which is of completely
new design and robustly dimensioned, is
fully synchronized and has four for-
ward gears. It is separated from the
engine crankcase by a divding wall, but
is integral with the final gear and di
rential to form a unit with its own lubri-
cating system.
Saab 99 LE Automatic — oil in place
of clutch dises
On the Saab 99 LE Automatic the power
is transmitted from the engine to a
hydrodynamic torque converter and from
this via a chain transmission to the auto-
matic gearbox,
The torque converter is filled with oil
and has three main assemblies: pump
impeller, turbine and stator, The pump
impeller is connected to the engine
crankshaft, while the turbine operates
the driving shaft of gearbox. The stator
is mounted on a free wheel coupling
with rigid hub. By way of the oil, the
pump impeller causes the turbine to
rotate, When the driving and driven im-
pellers rotate at different speeds, the
stator leads the oil back again to the gp
pump impeller in such direction that
the torsional force of the impeller in-
creases. The gain in torque can vary
from maximum 1.9:1 down to 1:1 and
ceases when the turbine has reached a
rotary speed of approx. 90 % of the
pump impellers.
Because of its capacity to increase
engine torque, the converter helps
give the car good acceleration from
low speeds, without downshifts,
Page 27
Therefore, the power is always
transmitted smoothly.
Selector instead of gear shift lever
Gear shifting takes place automatically
via a hydraulic system with pump, go-
vernor, valves and servo-pistons, which
operate the various units in the gearbox
according to the position of the selector
lever and general operating conditions.
Kick-+Jowns can be done at speeds
below 50 m.p.h. by depressing the
accelerator to the bottom, The
selector lever can be put in six positions:
P=Parking. This is engaged so that
the ignition key can be turned to L-
‘Wsition and removed. The lever and
gearbox are locked.
R= Reverse.
N=Neutral. No power to the driving
wheels, the car can roll without
Qpndrance.
D=Drive. This is used for all normal
forward driving. Automatic gear
shifting through the entire range
2=Drive with 3rd gear locked.
1=Drive, only in low.
This is used up very steep hills and when
extra powerful engine braking is
needed
The automatic gearbox is made by Borg-
Warner and has given ample proof
that it is well suited for Saab 99 LE
The engine is assembled with clutch, trans-
mission and differential into a complete and
compact power unit. The clutch is mounted on
the Front of the engine and the transmission
lies underneath the engine, separated by a wall.
Engine and transmission have separate
lubrication systems.
The top illustration shows @ 2-liter carbureted
engine, while the lower illustration (Fig, F)
shows an engine with electronic fuel injection
combined with a manual transmission
27
Page 28
In Europe: Newton-meters and kilowatts
instead of kgf m and hp
One horsepower is not the same in all
parts of the world. In countries which
base most of their units of measurements
on the c.g.s. em, | hp is defined as
75 kgf m/s, while the corresponding
power unit in the USA (1 hp) has a value
of 76.04 kef m/s. The difference is of
course due to the fact that it is not pos-
sible to arrive at exact agreements bet-
ween the metric system and the system
using “pounds” and “feet” without using
inconvenient numerical values.
Our present system of units is unsatis~
factory in many respects, It is not com-
pletely uniform and often requires
troublesome conversions between diffe-
rent sorts of units. A new system has
therefore been adopted — the SI system
(Systéme International d’Unités) —
which covers all branches of physics and
engineering with a limited number of
units
The SI unit for force is 1 Newton (1 N),
while mass is still measured in kg, The
old force unit of | kgf corresponds to
9.80665 N. A torque of, for example, 15
kgf m is approx. 15*9.81=147 Nm.
As a unit of power, the SI system em-
ploys | Nm/s=1 W. 1,000 W=1 kW=
0.735499 hp. 100 metric hp, therefore,
equals approx. 73.55 kW.
Power and torque
1972 Saab 99
1.85-liter carburetor engine
G, The 2-liter engine differs its predeces-
sor In many ways. It has, for example, a some-
what taller engine block which permits the
use of longer pistons with more rugged piston
pins, The increased distance between the top of
the piston and the piston rings results in the
rings working at a lower temperature, The
1,85-liter engine piston is on the left, the 2-liter
engine piston on the right,
H, The overhead camshaft in the 2-liter engine
is driven by a double chain,
I, The new, larger Swedish-built engine has
a more rugged valve mechanism and a modified
combustion chamber,
The valves move in parallel with the cylinder
bores.
Power and torque
1973 Saab 99L
2.0-liter carburetor engine
Power and torque
1973 Saab 99 LE and Saab 99 EMS
2
2.0-liter fuel-injection engine
nk kW ; Nm kpm hk Nm_okpm hk kW - —_ Nm _kpm
= = | al | J |
ad SS ei T04-gq——}—}— 10 Leds eo FRU
seo ES os of ttt i
7 70 79 ——| 1
as 80 T a | mS
90}— + ay 1% Gi _ 180. Lanes 4 =i :
= { e rye inna hs
Pas F160 E160 ai 60 |
at i Peps 80: na ~~ 6
=~ 40 | FH} 70 40 ag
+} F320} tp Peo © 60. f — ii 12
20} 10 EWOlig 50, f as E1001 10
j an es 4043 T
20
2
20 vAu =e
} a
i 4 10 os =
1900 2000 3000 4000 5000 6000 ¢/min 1900 2000 3000 4000 5000 6600 1/min 7000 2000 3000 4000 $000 6000 +/min
28
Page 29
Safety body.
Saab 99 LE has a self-supporting all-
welded steel body (A). In many places the
steel is considerably thicker than what
is normal in the automative industry.
The weight of the complete steel shell is,
however, low, bearing in mind the
spaciousness of the car.
The passengers are surrounded by strong
beams (Fig. B, C, D), while the front
and rear portions of the body are desig-
ned to prolong the stopping stretch, in
the event of a collision, by deforming
and absorbing the impact, (With colli-
sions at low speeds the possibilities of
the bumper absorbing the impact are
much greater, (See page 11).
The windshield beams (Fig. B, C) are
constructed of 40 in. long, and very
strong, steel profiles, which are welded
to the bottom of the wheel housings.
The saddle beams sills and side beams are
also extraordinarily strong. Around
the roof line there is a reinforcing steel
rail, Cross members above the floor
contribute to the transversal rigidity
(Fig. D). As a protection against buck-
ling under pressure, the doors are rein-
forced with longitudinal rectangular
members of profiled tubular steel (Fig. E).
The shell around the cabin has shown
its great impact durability in many tests,
for example; An upside down Saab 99
has been dropped onto a concrete floor
from a height of 7 feet without the
windshield — and side beams being
crushed.
The priming is carried out according to
the electrocoating method. After the
__ body has been phosphatized it is immers-
ed in a bath of anti-rust primer (Fig. F),
where the particles, with the aid of strong
electric current effectively adhere to
all steel surfaces, and along edges and in
cavities, Before the body receives its
final coating it is given a protective and
sound absorbing layer of undercoating
compound underneath and in the wheel
housings (Fig. G),