HIGH ALTITUDE MANUAL
by Don Wollum.
(Note: The following was provided
for those who registered to attend the 1999 National Saab Owners
Convention held in Keystone, Colorado.)
Driving in the mountains, particularly
as it pertains to oxygen levels and atmospheric pressure, presents
special challenges to vintage Saab's, 20 years or older. Whether
you own a 1959 93B or a 1999 9-5, this altitude information will
be important to know.
Section one: Physics of high altitude automobile operation
General Recommendations for All Saab Cars
- Brakes and Brake Fluids
- Fuels and Fuel Delivery
- Cooling System and
Recommendations for V4s and 99/900 thru 1979.
Recommendations for 2-strokes engines
Safety on the Interstate Highways
While tips are offered for assisting at
altitude, the risk for engine damage is real if you exceed these
settings! Equally vital is that below 5,000 ft., reset your engine
tune specs to standard sea level specifications.
CARS, SAAB CLUBS, and CONVENTION SPONSORS, and article author,
disclaim financial losses.
of High Altitude Automobile Operation
Why that Mountain Monster
hits so hard
Sub-stratospheric conditions above 10,000
ft., robs your engine's power output a full 34 %, due to a combination
of lowered oxygen levels, and a significant reduction in atmospheric
pressure values at altitude.
Punch # 1.
Oxygen tends to settle to low places, due to atomic weight molecular
theories and gravity. Oxygen levels found at 5,000 ft. are a
full 14% less than levels found at sea-level. At 10,000 ft. this
percentage loss of oxygen now approaches 30%. As carburetor jets
remain fixed, the diminished oxygen in the thin mountain air
will burn poorly with the carb's fixed amounts of fuel. The logical
outcome is black smoke from the tailpipe, and poor mileage, and
significantly reduced power outputs. Hold on though, you are
about to discover the second power robbing aspect associated
with high altitude engine operations.
Punch # 2.
concerns atmospheric pressure that we too often underestimate.
Its easy to do, most Americans live at elevations below 500 ft.
and are essentially at sea level. This is our normal condition
to live and breathe in deep, rich, heavy air. Atmosphere pressure
is proportional to the weight of all the above molecules resting
and pressing down to the bottom from miles above. Remember diving
to the bottom of a swimming pool, how with increasing depths,
the extra water pressure hurts your ears. Atmospheric pressure
is alot like the collective height / weight of the water molecules,
but instead we are talking about air molecules. We are quite
accustomed to life at the bottom, under the weight of miles of
air molecules that are stacked above you. Now consider the opposite,
at Keystone, we will experience the absence of the two miles
of air molecules, the ones we left behind and below us in Eastern
Kansas. Air pressure differentials are what lifts a hot air balloon
and its heavy gondola off the ground. Ever hear about Colorado
Rockies home-run advantages with thin air at Coors Stadium. Baseball
statisticians add an asterick to the batter's home-run numbers
for runs hit in Denver.
Let's return to situation back underneath
our hoods. It follows then that less of air molecules resting
and pressing above our throttle plates at 10,000 ft. will fill
our motor's cylinders less effectively when the piston travels
down. Furthermore, this slower fill rate is now at odds with
the sea-level designed camshaft timing values. The mechanical
time the valves are open will remain the same, yet due to the
reduced atmospheric pressure, far less mixture will enter the
cylinders. Clearly this will remain the key power robbing component
that we will be least able to compensate for with our adjustments.
Two-stroke motors use ports in the cylinder wall to time air
flows and these ports are the equivalent of the 4- stroke's camshaft.
The two-stroke is so dependant on heavy sea-level pressure differentials,
that at altitude, intake, transfer, and exhaust back pressures,
will be disproportionately disrupted, robbing the two stroke
motor of greater torque than 4-stroke motors.
Ok ! Now that I have got your attention,
my recommendations are to make some simple and prudent altitude
adjustments and changes. There is no magic answer, nor specific
settings for regaining sea level power! Realistically, your Saab's
can only perform with less vigor, but you and your Saab will
arrive at Keystone Colorado just fine! Enjoy the many pictures
taken of you car on each breath-taking scenic overlook. Be cautious
and do not over-adjust and ask a "bit more" from tune
specification. Over adjusting will do actual harm to your engine,
and also cost you plenty in delays, breakdowns and towing expenses.
Every fellow Saab conventioneer wants you to arrive safley,on
schedule and certainly not hot and irritated from unnecessary
- gentle leaning of mixtures
- mild advances of timing
- keep rpm's high
PLUS: General maintence recommendations
and safe & knowledgeable tips for high altitude mountain
High Saab and other Saab repair
shops in Denver offer a tune check for those heading up to the
Rocky Mountains. It is usually necessary to make an appointment,
and there is usually a small charge for adjustments if needed.
Your sea level tune settings will work okay up to Denver.
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Recommendations for Mountainous Conditions
and Brake Fluid
Good brakes are essential for mountain
driving! The old adage "what goes up, must come down",
has never been more important. Besides new pads and shoes, there
are two other components of the brake system that will need to
be in top form. Some grades in the Rocky Mountains will be over
ten miles with grades of 8% or more. With the tremendous length
and steepness of the decent, everyone's brakes will get extremely
hot, cars and trucks alike. I guarantee you will see smoke and
smell the damaged pads and overheated rotors of others who imprudently
ride the brakes and develop problems with overheated brakes.
Here are some tips:
- Total brake heat is affected by the rate
you slow down in, so lengthen your stops all you can. Total brake
heat is also affected by highest speed you start slowing down
from, so don't allow initial speeds to build. Downshift and spare
the brakes on the really steep grades, cool brakes by using third
gear to allow 30 second rests.
- Flush your brake system with a DOT-4 Castrol
fluid, stem to stern, to avoid boiling of the brake fluid. Brake
fluid is hygroscopic and water will boil an "air pocket"
in your system, especially at altitude, because the boiling point
of water is now 187 F. Do not upgrade to silicone DOT-5 unless
all seals and cylinder are new! You will spring seeps at most
containment seals due to seal shrinkage reacting to silicone.
Pedal bleeders are now asked to limit stroke by placing a small
block of wood under the pedal. This great idea will avoid trashing
the seals mucking through the grunge that resides in this unused
end of the Master Cylinder bore.
- Measure your brake rotors for overall
thickness. The point here is to have enough metal mass to store
excessive heating that mountain use will bring. Again you will
be traveling DOWN ten miles of 8% grade! Replace your rotors
if they are deeply worn, or overly turned on a lathe. Spend a
few minutes with a MM Micrometer and measure against factory
specifications. Thin rotors will turn red hot and the pads will
not grip the burning, smoking, thin, rotors. Runaway ramps are
for trucks having emergencies, not Saab owners!
- Also, do not neglect to bleed the clutch
system, especially on 900, and 9000 models. I have received more
complaints of clutchless cars on the contenetal divide than all
other complaints combined. The reason is after a 55 minute pull
to 10,000 ft., engine heat given up by the A/C condenser, Intercooler,
Radiator, all penetrate the trans chain case and boil the often
neglected brake fluid still residing in the slave cylinder.
- All Vintage Saabs need to also go DOWN
the hills in the same gear that you went up the hill in. Pre-mix
2- stroke may use 4-th gear only on interstates and remember
to pull the choke out to wet the insides of the motor with oil
every 20 to 30 seconds or so. Drum brake 96's need to pull over
often for extra cooling, minimum 10 minutes, or consider spraying
the steel wheels with water from a garden sprayer to help cool
the drum brakes.
Fuels sold in Colorado and other high altitude
states in the West, are generally 2 points lower in octane. Simply
buy the same grade of fuel you were used to buying at low altitude.
For example, if you had 87,89, 93, octane availiable in New Jersey,
your choices in Colorado now are 85,87,91. If you were okay with
middle grade 89 octane, your choice in Colorado will now be the
middle grade 87 octane.
Two factors will combine to create higher
engine temp. Obvious is the continuous pull up hill, and second
is the lower air mass that will decrease the amount of heat convected
away through the radiator. Your temp. needle will rest much closer
to the hot area and this is ok provided the needle is not in
the red and does not radically raise or lower in less than one
minute. Running of the A/C is ok, provided you can spare the
5 horsepower. If you need a bit more engine cooling on hills,
turn on the heater and open the windows. If you have any doubt
that your engine is too near the red, immediately seek the advice
in your owners manual or seek technical advise. Do carry some
apare antifreeze, and/or use the new coolant "wetters".
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Saab 99, 900's,
and all V-4 models including Sonnets.
Note! Do not make these changes
until 5,000 feet above sea level (1 Mile High).
Reverse these settings under 5,000 feet!
WARNING: Do not exceed these values!!!
In general, timing specifications can be
advanced a few degree's beyond factory spec. It is extremely
important to remember that no one "advance law" will
fit all versions of Saab Engines. If you could generalize ignition
advance recommendations, they would be: Above 2,000 feet, one
degree advance for every two thousand ft. of altitude increase...
TO A POINT! Once you get above 8 thousand feet the physics involved
are too great to adjust around. Do not add more than four degrees
under any circumstance. The theory of altitude advance is to
give the lower oxygen mixture a better chance to burn by beginning
the ignition process earlier, and more power is developed. Timing
specifications will also increase manifold vacuum. This also
is a good side benefit.
The following specs are for idle, with
vacuum advance plugged & disconnected, using a strobe timing
light. If at any time you hear or suspect detonation, cut by
half any timing change, or return to stock settings.
Model: Factory timing Altitude Timing
All V-4 models:
6 degrees 10 degrees
Carb w/1.7L & 1.85L eng. 10 degrees 14 degrees
EFI w/1.85L Triumph eng. 6 degrees 10 degrees
Carb w/2.0L "B" eng. 14 degrees 18 degrees
EFI w/Saab "B" eng. 12 degrees 15 degrees
CIS w/Saab "B" or "H" eng 14 degrees 16 degrees
You will notice a trend here as engine
and fuel management systems evolve, timing advance recommendations
become less. Modern fuel managements systems with Oxygen Sensors,
all models after 1980, have vastily improved mixtures will need
even less timing advance. Later in the 90's, computerized spark-systems
as EZK, Motronic, and Trionic, will automatically advance the
ignition timing with built in safety precautions. It is wise
to know "knock sensor" motors will benefit from higher
octane numbers. Your fuel choice will be assisting the computor
with keeping the timing optimized. Poor fuel octanes will degrade
engine performance as ping will negate and erase "advances"
in computer spark mappings.
SAAB TURBO MODELS SHOULD NOT RECEIVE
ANY TIMING ADVANCES. Turbocharged
engines are pressurizing the intake charge as if at sea level!
When the stuffed cylinder is then compressed the risk is high
for detonation due to boost aided compression factors alone.
Use priumum fuel only, and all 900, 9000 16-valve motors (without
Direct Ignition) will need NGK BCP7EV plugs. DI motors need resistor
plugs at all times, consider the trusted NGK brand BCPR 7 ES
While we are on the subject of detonation,
be aware that some 85- 88 CIS 900's could have defective preheat
flaps that stick and give heat to the air cleaner at all times.
At temperatures above 80 F. this hot air leans the mixture to
a point where detonation occurs at mid to full throttle. If you
hear ping on hard pulls, remove the stove pipe (aluminum tube)
at the exhaust end and re-test drive under heavy load conditions.
For stop gap, remove the aluminum tube (at exhaust side) and
reroute to cool air source behind left front H/L.
Additionally 900 EZK spark models tend
to ping briefly with abrupt throttle openings, under load, especially
when hot. A brief acceleration "ping" is normal. If
ping continues for more than 2-seconds, change to high test,
or seek Service advice. All Saab engines without Electrical Idle
Motors, will idle lower, due to less dense air. Your cars steady
900 rpm idle speed at sea-level low altitude, will sink to 500
rpm at Keystone, and this topic will lead us into discussions
on air / fuel ratio's and mixtures, carburetors and fuel injection.
This section will discuss important fuel
design compromises and discuss fuel adjustment limitations!
4-stroke Carbureted engines suffer the most when driving at high altitude.
High altitude air movements in a carburetor will more resemble
the unstable air flow around an aircraft wing when it encounters
stall speeds. The chambers in the venturi were designed with
shapes and spaces that would effective in mixing liquid fuel
with air at sealevel. The long and short of this discussion is
that little can be done to give great air/fuel ratio's at altitude.
The advice is as follows: keep RPM's up to increase air velocities
within the carburetor to "normalize" the mixing fuel
and air flows. A second benefit to partial throttle settings,
and high RPM's, will be the creation of a secondary fuel atomizing
area around & below the throttle plate.
To provide optimal amounts of air to the
engine, a new filter is imperative. Also make sure air offered
is cool as possible. If you still have original metal snorkel
on the early V-4 or Pre 72 99, split the end opening on the bottom
and widen this restricted air inlet. Also ensure that the fuel
system filter is new, and that all fuel hoses are not cracked
(suction and pressure) and the pump is good and hopefully new.
If you don't actually replace the fuel pump consider at least
pack new one along, and you could even carry a spare electric
pump along. The reduced atmospheric pressure can cause fuel vapor
lock, but not always in the carburetor! Vapor lock is often in
the pull side from the tank. Electric pumps can be mounted near
the tank, greatly reducing the the chances of fuel delivery vapor
All carbs will need the idle setting increased,
and the idle mixture thinned out, by turning the idle mixture
screw in. Do not change the main or pilot jets to anything less
than stock values. Remember that you will be flooring the motor
flat out, at high speeds for 10-15 minutes or longer. Please
do not burn your valves or pistons doing the impossible by re-jetting
your carbs lean! Standard jets sizes only. Hopefully at sealevel
you were running the jets a little fatter than specified for
better power. Stromberg carburetors need only idle speed adjustments
and idle air trim adjustments (screw adjuster out) to increase
air bleed and lean idle. Do not play with needle position or
main jet position. The Stromberg carb will self adjust better
than the fixed venturi carburetor. Do carry a spare piston diaphragm
along, as would this diaphragm develop a tear, you are completely
EFI systems, 1970-1974, tend not to respond well to adjustments, and the
parts are now old and fuel pressure and manifold sensor diaphragms
are brittle and weak. RIGHT NOW, if you have good driveability
and good gas mileage , consider leaving well enough alone. Only
if your mileage on a highway is below 24 MPG at 60 MPH, should
you seek information or a technician to lean out the mixture
. Or, if your highway mileage is above 32 MPG at 60 MPH, seek
information or a technician to richen the mixture. CO gas analyzers
do an ok job informing the technician of relative CO changes,
but consider actually preforming a true 30 mile highway mileage
test. Lean surge was often mistaken for throttle switch deficiencies,
but unwittingly you may be running far too lean. You could have
the unfortunate experience of burning a valve. Do the mileage
test out on the road to where you can drive at 60 mph for the
majority of the miles specified. True technocrats could weld
threads for an O2 sensor in the front pipe, and help the technician
get road readings.
CIS systems WITHOUT Oxygen Sensor, 1975-1979
Federal States version
Continuous fuel injection is very accurate in metering fuel in
proportion to manifold vacuum and does "ok" with altitude
gain. Less manifold vacuum will lift the air sensor plate less
so fuel delivered is less also. Lets say that your CO was at
2% at sea level, it would now measure 5% at 8,000 ft. This value
is not as "off" as it may seem, as CO is still combusted
fuel that could have benefited from more air to bond with carbon
to form CO2. Look at the other side of the fuel equation, 95
% of the carbon did bond with air to form CO2. At altitude, adjustments,
your power and mileage may still suffer and you will not have
gained alot from CO adjustments
CIS oxygen sensor FI systems,1977-1988
These CIS cars have mixture override systems to correct for combustion
variances, including altitude driving. Enjoy your trip without
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The goal is to drive to Colorado and return
with a increasing rare and very unique, fun to drive, power unit.
Because two-strokes fire on every stroke, more heat is given
to the pistons and petroil provides precious little lubrication.
If the expansion of the piston goes unchecked, minimal oil offered
by the fuel can turn directly into power robbing friction. Worst
case is the complete seizure of the piston in the bore. All issues
discussed below are vital in protecting the two-stroke motor
against the damages caused by heat and friction.
Fuel and carburetion: Use the best available grade of Premium fuel for
all models, plus additions of octane boosters for all Monte-Carlo's
up to 5, 000 ft. When the Stroker gets in the middle of its power
curve, combustion temps and pressures are high performance!
Monte Carlo carb jets
- Mains: 120, 135, 120
- Pilots: 55,or 60 (no 45's )
- Emulsion air jet: 200's, 180 at altitude,
Pre-mix tri-carb jets
- Mains: 125, 135, 125
- Pilots: 55, or 60
- Emulsion air jet: 150 to 5 K., and 180's
Two-stroke Oils: Two-stroke oils are available at your local motorcycle
shop and/or personal water craft dealers. There are two types
of two stroke oil available, PREMIX and INJECTOR. Generally the
premix oils are of a heavier viscosity, like 30 wt oil and is
mixed directly in the gas tank. The premix oil is then separated
and re-deposited by the movement of the vaporized fuel, and just
the oil is deposited on internal engine parts. Injector oil is
a lighter formula more like 10-30 oil, because this oil in motorcycles
is dispersed in the air stream just after the carburetor, it
needs to be thinner to catch the wind. Some oils are listed as
suitable for both and measure "inbetween" in viscosities,
are available in either standard or synthetic formulas.
Generally all two-stroke oils carry the
government rating TC-W3, and are fine for all pre-mix two-stroke
motors. Saab manuals in the past specified premix oils because
of the heavier size oil molecules. The total lubrication quality
of today's oils are so far superior, that the advice Saab gave
is no longer true. Mix the oil to gas ratios as specified in
your Saab owners manuals for high speed driving (more oil). Be
aware the modern motorcycle - watercraft oil you purchased may
call for lesser amounts of oil. If you are confused follow directions
for the new standard TC-W3 oil and add 20% more oil to the same
amount of specified gasoline. This basic two-stroke oil costs
about $20.00 a gallon. New on the market are part synthetic blends
and are priced only a few dollars more for the same gallon amount.
100% synthetic oils are available but have a significantly higher
cost, around $ 40.00 a gallon. Blended or full synthetics should
be used in slightly heavier amounts 10% above directed amounts
listed on the package label. I would highly recomend the part
synthetic blended or pure synthetic two- stroke oils for all
Saab motors. Do not use additives with synthetic oils, they are
very sensitive to disruption or stratifying. I do not recomend
plain TC-W3 oil for Monte-Carlos as their minimized oil supply
should only be of maximun oil quality. If you must economize,
use Yamaha 2-S blend. Because Saab's oil pump injection will
"pipe" the oil directly to the cylinder wall and engine
bearings, synthetic lubrication will be less viscous but more
stable and total oil consumption will remain about the same.
The best benefit of synthetic oils are markedly reduced smoking,
because more oil is staying inside the engine.
Cruising a pre mix stroker steadily above 3,000 rpm could cause
a condition where the friction consumption of lubricating oil
can exceed the amount delivered by part throttle cruise conditions.
This is our typical flat interstate driving which was inconceivable
to Sweden in the 1950's. When this engine prowled the roads in
its prime, then 45 mph was the top posted speed for fast roads.
The Germans with high speed autobahns, also fancied the Saab
motors ,and developed a process of wicking the oil ( up to the
pistons ) by running with generous oil ratio's and fat carb jets.
Saab also was concerned with lubrication on overrun downhill
situations, no throttle open, but high rpm engine braking. Saab's
answer was to free-wheel the gear box, dropping to idle where
fuel and oil and friction loads all balanced out. On any hill,
you open the throttle enough to admit adequate oil, and, on downhills,
you should let your engine idle. The real danger condition is
flat-land, high speeds where you have very little throttle applied.
The pistons literally dry out because friction losses consume
more oil than what is deposited there from the fuel. Primarily,
your best and most effective strategy is to mix more oil (than
listed) with the gasoline, run prudent speeds, with a slightly
de-tuned motor. The goal is to have a doggy motor that you will
have your "foot into" a bit more to deposit more oil
inside it. Secondarily, also consider using these "wicking"
strategies for pre-mix motors: choke engine briefly, while engine
is still at speed, once per 2-3 minutes; allow engine to idle
occasionally/ for 20-30 seconds every 2 -3 minutes. This procedure
is easier if you think to let your speed on the level interstate
slow from 60 mph to 50 mph in neutral, then resume speed. Oil
pump motors can use additional oil in the tank at half listed
Saab two-Stroke motors are extremely high
performance motors and they required premium fuel. Monte-Carlo,
and standard motors suffered from detonation in the 1960's and
do now the 1990's. Detonation is devastating because of the extra
piston heat incurred going up, and going down will quickly begin
to melt the pistons. Detonation sounds like a lite wispy crackle
primarily between 2,800 and 4,200 RPM with 30-70% throttle openings.
You can proof this noise as detonation by pulling out the choke
half way, briefly, when you think you may be hearing ping. "Ping"
is a hard to hear and all windows must be closed and no radio
on. Literally most drivers never hear two stroke ping as it is
of a higher frequency and lower volume than you might expect.
Also ping is not heard every time because heat build up has to
first occur. The hill has to be 45 seconds long or more and you
must be extracting full power, but not necessarily floored throttle.
To retain health for your two stroke
motor, set all Saab two-strokes at slightly retarded timing specifications
when at sealevel, and a little above specification at altitude.
Again this is due to the fuel octane being lower than in the
old days, and the really cold plugs are obsolete. The best you
can get are NGK A-8's and these are generally recommended for
all models. The other factor to help stop detonation is lower
coolant temperatures. Other overlooked sources of ping is to
test for low fuel level in the carb bowl. Generally one carb
tends to have a fuel level low enough to to upset the amount
of fuel delivered. Read on for tips to lower coolant temperatures,
primarily recoring the radiator. Also, do not use a vacuum advance
if your engine has one, until you eliminate all ping conditions
- Sea level timing: just below (retarded)
full adv. mark at 3,000 rpm,
On Road: DO NOT USE VAC ADV.
- Altitude timing: advance 3 deg. (1/8 th.
IN. or thickness of matchhead) above full adv. mark at 3,000
Cooling: Adequate cooling for 1964 and earlier 96's will
depend on radiators having an extra core run added (4 instead
of 3) and cardboard baffles refitted below the radiator area
. These baffles are imperative for the development of a low pressure
area behind the radiator for good air flow. Also consider using
"coolant wetting" agents that will cause coolant to
give up heat more efficiently. The same coolant advice goes for
1965 and up "long nose" 96's. Have the radiator recored
with one more row of runs added. Make sure you have working temperature
gages, good hoses and rad. caps and carry an extra h2o pump along.
Consider blocking off the extra space on either side of the radiator
to let all the wind stream pass through the radiator at highway
speeds. Remember to turn on the heat if you start to overheat
on long pulls in the mountains. If you get a hot runner and did
not get this sorted out before leaving, consider hanging a junk
yard heater core under the hood. Remove the original heater hoses
at the head and return pipe, let them hang, and add new hoses
to the spare heater core and duct air to it with clothes drier
vent tubing. this alone can low temps around 15 F. You can easily
remove this apparatus for the concours part of the convention.
A new electric H20 pump is available for emg. pump failures.
Lastly if you do have a 62-64 Sport Motor
with the original air cleaner, three little filters, no new filters
are available. You can scrounge and use the later Darth Vaider
65&up air cleaner assembly for which new filters are available.
Notch cut and fold back a 1 inch wide flat (half inch deep.)in
the area where the rear upright fan bracket hits. If you have
the individual carbs 62-64, be sure to use a VW bug inline fuel
filter and piece of hose to act a a source of filtered air for
the idle circuit. Exhaust pipes tend to close off with the carbon
and un burnt oil and will close off, restricting engine breathing.
Remove the rear muffler and look inside both ways, to the front
and in the muffler. If buildup is 1/4 in. or more, replace pipe
or muffler as necessary. V-4 rear mufflers are available, as
are pipes ft. to rear for the V/4, which will fit the 2-stroke.
A rear half section is available. See instructions for modifications
of these parts to fit your two-stroke. Lastly, tyre pressure
will increase with altitude. The 30 lbs. of "dense air"
you put in your cars' tires at sea level will now represent 40lbs.
Please recheck these part numbers with your local Saab partsman.
- Exhaust pipe , V-4 front to rear :________________________
- Exhaust Pipe, stroker, rear half :________________________
- Air Filter, stroker, 65 and up :__________________________
- Muffler, V-4 :_______________________________________
- Diaphragm , Stromberg :_____________________________
- Emergency electric water pump :_______________________
- 2-stroke spark plugs
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on the Interstate Highway
All slow Strokers are recommended to purchase
and use a bike strobic warning lite to set in the back window.
Safety on I-70 will depend on safely sharing
the road with faster and slower cars, and trucks. Most
cars will be traveling 70 MPH up-hill in the left lane, you are
pushing 3rd and holding on to 40 mph, in the right lane when
up ahead a steel truck is grinding up the mountain at 18 mph.
You either slow to 18 mph or merge to the left to "pass"
at a whopping 38 MPH, which by the time you decided your new
speed of 36 mph is now just below your power curve and 3rd gear
will no longer hold this speed. Here comes 2nd gear and 35 mph,
and the traffic behind is not immune to "road rage"
. Which brings us back to your little red strobic bike lite.
This flashing information will be just enough for most people
to figure your situation out as a special slow (especially slow)
vehicle, and they will possible display more graciousness and
courtesy. Georgetown to Silverplume is the steepest 2 mile segment
on I-70. It is here that you will have only one shot to hold
third gear. There is no shame to using second gear. If you get
caught behind traffic make the safe choice and slow down. There
will be another shot at third gear and that will hold till about
a mile from the Eisenhower Tunnel.
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Telephone numbers for advice:
- Don Wollum: 301-349-2149, 8:00 PM to 9:00
PM Eastern Time
- Bud Clark: 714-282-7378, 9:00 AM to 5:00
PM Pacific Time
Compiled and written by Don Wollum,
Saab Product Technical Historian and Vintage Saab Owner.
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