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Digital systems 4 gas systems are not affected by leaded race fuels.
Digital systems do not use "wideband lambda o2 sensors" - We use a completely different type of o2 sensor - It's only $150
to replace, lasts more than a year and is what EPA uses in all their test
equipment for o2 measurements -
EPA does NOT use "wideband o2 sensors" to test..
Compare to $200 to $400 for fragile, wideband o2 sensor.
O2 sensor and a/f ratio + lead = potentially big expense and wandering af readings
Digital systems are not permanently affected by liquid water.
Liquid water kills wideband o2 sensors - instantly.
O2 sensor and a/f ratio + water = big expense
Digital systems are not affected by
leaded fuels.
One USA race team has to replace their wideband o2 sensors every two
weeks due to lead fouling.
Digital systems - don't care about the lead in race fuels or aviation
fuels.
O2 sensor and a/f ratio = no leaded fuels allowed
Factory Pro method = lead has no effect
Digital systems o2 sensor generally lasts over a year
with multibike, daily use.
(ours is used that much!)
Digital systems CO, HC and CO2 mass spectrometer
equipment rarely fails in use without warning.
O2 sensor and a/f ratio = no information and no warning -
Factory Pro method = constant 4 gas zeroing ability
Digital systems use CO% as a much more reliable and consistent indicator of mixture
strength.
If 5% CO made best power at some rpm and throttle position, you could
also tune all other throttle positions and
rpms and even idle to 5% and you'd have a nice, smooth running engine.
If you used an 02 sensor and tuned to the magic 13.1:1 AF Ratio at full
throttle AND at part throttle and at cruise and idle - it would commonly
be too rich at cruise and part throttle and the customer, if they speak
up, will not be happy with cruise. Especially common with HD's and big
cruisers that spend a lot of time at part throttle.
O2 sensor and a/f ratio = changing af target throughout the rpm and
throttle band and that's why a good tuner, using a wideband o2 sensor
only, has to spend hours to fiddle with "target" af ratio values
to get something that runs "ok".... hours of fiddling.... did I
mention..... "hours of fiddling" vs. an hour of manual tuning?
CO% = changing target CO%, maybe as much as a whole 1 %..... Less time
tuning - more accuracy - happier customers.
Better tuning and more profit.
Digital systems use HC as an indicator of engine efficiency.
Lower unburned hydrocarbon ppm (parts per million) in exhaust,
when finished tuning to Best
Power indicates good overall state of engine health - you'd even see that large
bore engines, at 200 to 300 ppm, are cleaner burning than small bore engines,
usually 600 to 800 ppm). That's due to increase boundary area.
O2 sensor and a/f ratio = no information.....
Digital systems use HC and CO2 to show "over advanced" ignition timing.
Generally, after you finished fuel tuning, you'd see high HC and low
CO2 - and that
would indicate that you should try backing off the ignition timing. If
it's too advanced - the power will improve as it's retarded and the HC
will drop to <1000 ppm, due to better combustion efficiency.
O2 sensor and a/f ratio = no information.......
Digital systems use O2 as just an indicator of how
much oxygen is left.
If the engine is making Best Power with a particular fuel stagger and
/ or ignition timing, and the o2 value is above 1%, I'd look at improper
fuel stagger and retarded ignition timing - Retarded ignition timing
increases the O2 level in the exhaust - so we don't rely on it -
O2 sensor and a/f ratio = all eggs in leaky basket..........
Hint and fatal flaw in wideband o2 sensor tuning and why you don't get
Best Power with tuning to "an A/F Ratio".
O2 gets left in the exhaust for many different reasons, like
dilution, ignition timing, fuel additives, emissions systems, improper jet
or FI stagger.... all affecting the O2 readings........ and all cause dyno
users to tune wrongly - Usually
causing the tuner to over richen the mixture to make the so-called a/f,
appear right.....
And - even if you actually were getting a real a/f ratio - the "optimal
power a/f
ratio" would change based on every throttle opening and rpm.
(unlike the CO%, which doesn't change much, based on throttle position,
rpm or ignition timing)
Digital systems use CO2 as a clue to "retarded from best power" ignition
timing.
If you've optimized fuel for best power and the CO2 is less than 9, it
indicates that you should try advancing the ignition timing. Power will
increase as you advance the timing to optimal setting, the CO2 will
approach the 10% range if the fueling is correct and you reach tuning perfection.
O2 sensor and a/f ratio = no information..........
Digital 4 gas systems use CO2 as in indicator of general, overall fuel and
ignition timing optimization.
If you are making Best Power and the CO2 is 9.9 to 10.2,
you HAVE:
optimal fuel on EACH cylinder
optimal ignition timing on EACH cylinder
and you are 99% sure that you are making all the power that that
engine can make and no change of fuel or ignition will make it better
-
O2 sensor and a/f ratio = no information.....
Congratulations.
You have just succeeded in exceeding the power and engine smoothness from maps done by "Tuning
to an A/F Ratio" with a wideband o2 sensor.
All they can do is tell you that
your so-called "A/F Ratio" is "all messed up... but it makes good
power......"
............................
Technical information:
Marc Salvisberg
Factory Pro Tuning
179 Paul Drive
San Rafael, CA 94903
800 869-0497 |
