Code59 201
SyTy Nats 2009
Bowling Green, KY.
What’s Code59?
• Code59 is free stuff to help you tune
your truck for better power, reliability,
mileage, and driveability.
• Code59 includes
• Tools to help with tuning
• Base binary images (chip files) to get
started with, for various builds and
injector sizes
• Definition files for TunerPro RT so that
it understands Code59
• Not just SyTy… many others
too!
Why use Code59?
• We made it better – improvements to the base GM “operating system”
to make it easier to tune, with integrated Wide-Band o2 capabilities.
Also, tools like AutoTune to do a bunch of the heavy lifting for you.
• Purchased “chips” are hit-n-miss; some will work ok on your truck,
some won’t.
• Does what the aftermarket systems (FAST,DFI) do, for a lot less.
• You can do this stuff! Tune it yourself to save $, and get better results
than what you can buy off the shelf.
Thanks!
Moving Forward
• I’ve got all the stuff, and it’s all set up and
working. Now what?
– Get the right mind set… this very likely will take
a long time to get right.
– You have to walk before you can run… you
need to have a good driveability tune before
you work on WOT (Wide Open Throttle)
issues.
– Tunes evolve over time… they’re not a onetime event. GM develops factory calibrations
over a fairly long period of time.
What is a Good Tune?
• A good tune idles well, or as well as can be expected
given the engine build you’re working with.
• A good tune drives nicely; it doesn’t die when you back
up, or pull up to a stop sign, or turn the A/C on.
• A good tune is smooth. It doesn’t jerk/buck at part throttle
or WOT.
• A good tune will get respectable fuel economy.
– 10 MPG isn’t respectable.
• A good tune has no detonation. A motor that has 4+
degrees of knock retard on a regular basis will develop
rod bearing or piston ring land problems eventually.
• A good tune has margin built in for varying gas quality,
and atmospheric conditions. (ie, it’s not at the edge all the
time)
• A good tune makes good power
Fueling
• The amount of fuel the engine gets comes from
the following equation:
BPW = BPC * MAP * T * A/F * VE * BVC * BLM *
DFCO * DE * CLT * TBM
• Sometimes referred to as the “Speed-Density”
equation.
• Lucky for us, we don’t need to know anything
about the above to get the fueling right.
Fueling
• So… what fuel is needed… and where? A little
background info:
– MAP = Manifold Absolute Pressure
• This is the 2 Bar, 3 Bar stuff you keep hearing about
• As the name suggests, it’s absolute pressure. Normal absolute
pressure (AKA the barometric pressure) is roughly 100 Kpa
(14.68 psi) at sea level.
• A 2 Bar sensor reads 2x normal pressure, or 200 Kpa,
including the normal 100 Kpa.
• A 3 Bar sensor reads 3x normal pressure, or 300 Kpa,
including the normal 100 Kpa
Fueling
• More about MAP
– MAP = Engine load.
• With the throttle plates closed, and the engine running, MAP
will be at a minimum. Engine load is also at a minimum…
you’re either coasting or you’re idling.
• At partial throttle, MAP is getting some air from the outside
world, and so MAP is a bit higher. Load too, is a bit higher than
it was with the plates closed.
• At full throttle (WOT), MAP is at a maximum. In non-boosted
applications, MAP will be at or near whatever the outside air is
at (Barometer pressure). In our boosted engines, it’s whatever
the outside air pressure is, plus boost.
Fueling
• More about MAP
– Increased load (MAP), means fuel demands
increase.
• It stands to reason that the more load is on a motor,
the more work it’s doing. So, it needs more fuel to
do that work.
• How much fuel? We’ll get into that in a bit..
Fueling
• How does RPM fit in?
– As engine speed increases, the amount of air it
moves increases as well. (up to a point)
– This results in a “curve” that begins to fall off at
an RPM where the cam and heads begin to
flow less air
– Since the amount of air is increasing, the
amount of fuel needs to increase to maintain a
proper Air/Fuel Ratio.
Air/Fuel Ratio
• So what is the proper Air/Fuel Ratio(AFR)?
What’s the magic number?
– Short answer: There is no single magic
number.
– There are some general guidelines; good
places to start. When in doubt, stay on the rich
side!
– In the end, your engine will tell you what it
likes. Listen to it!
Air/Fuel Ratio
• AFR “zones”
– Idle
• Generally in the 13:1 -15:1 range, although some
big cam motors will like even richer (numerically
lower) mixtures to idle smooth.
– Cruise/part throttle
• 13.5:1 – 16:1, although not all builds will tolerate the
lean end of that range. Leaner is going to result in
better fuel economy, given the same RPM and
throttle position.
Air/Fuel Ratio
• AFR “zones” (continued)
– Moderate acceleration
• A transition period between normal cruise and full throttle
operation. Usually, this will be a blend between your cruise
AFR and your WOT AFR.
– WOT
• Depends a lot on what kind of gas you’re running.
• Max power generally happens in the 12.3-12.9:1 range for
boosted engines, although you will rarely run one that lean
unless you’re pushing the limits and don’t care about blown
engines.
• Street Gas tunes end up being in the 10.9-11.9:1 range,
generally.
• Race Gas tunes end up in the 11.2 -12.5:1 range
• Alcohol Injection tunes end up in the high 10:1-low 11:1 areas,
although there is a wide difference depending on how your
system is set up.
Air/Fuel Ratio
• AFR zone pic here?
Fueling Modes
• Fuel delivery operates in a few distinct
modes
– Open loop
– Closed loop
– Power Enrichment (PE)
– Accel Enrichment (AE)
– Decel Enleanment/Decel Fuel Cut Off
(DE/DFCO)
Fueling Modes
• Closed Loop/Open Loop Fueling
– Terminology: Closed/Open loop is not fueling specific,
it just means the system uses feedback from sensors
to adjust itself. There are other “closed loop” systems
at work in the ECM, so don’t get confused.
– In the context of fueling, Closed Loop simply means
that the system is using an oxygen sensor to
determine the running Air/Fuel ratio, and is using that
information to adjust fuel.
– Conversely, Open Loop means that the system isn’t
using any feedback from the sensor; it’s just delivering
a fixed amount of fuel.
– Closed Loop only happens at part throttle/cruise/idle; it
doesn’t occur at WOT or PE.
Fueling Modes
• Code59 can operate with 2 different closed loop
fuel methods
• Stock Narrowband closed loop – works just like the factory
system did, shoots for a 14.7:1
• Code59 Wide Band closed loop- uses a wideband o2 sensor
and the F29_AFR table to hold AFR to values you specify in
the table.
(Credit: Don Dibble developed the code for this, Thanks Don!)
• It’s important to note that you need to get your tune “close” in
open loop mode before turning on either of the closed loop
modes; weird operation can result if you don’t.
• Don’t try to use closed loop as a crutch for a bad tune. 99% of
your tuning work will be done in open loop!
Fueling Modes
• Wide Band Closed Loop Fuel in Code59
Fueling Modes
• Power Enrichment (PE)
– Like the name suggests, PE is in effect only when a
heavy foot is applied.
– Doesn’t have to be full WOT, although PE is in effect at
WOT. It’s meant to provide additional fuel as needs
dictated.
– PE AFR -vs- RPM (F61) Table is what drives this. It
gives a list of AFR ratios, but the numbers there won’t
match up to ”real” AFR. In the end, they’re sorta
arbitrary constants
– While it sounds like this table would get used a lot, in
reality, most tunes leave this alone. We’ll get into why,
a bit later.
Fueling Modes
• Acceleration Enrichment (AE)
– Sorta like the accelerator pump shot on a carb
– Why AE?
• There’s a delay (known as transport delay) between the time
fuel is delivered, and the time it gets to the cylinders. Adding
an extra shot of fuel prevents a stall/stumble on quick throttle
openings. This fuel is delivered asynchronously, which means
it’s not necessarily timed with ignition or cylinder events.
• The delay gets worse the further away your injectors are from
the valves. Our port injection is fairly close to the valves, so we
don’t need a whole lot of AE. (It doesn’t help us much)
• The AE tables (F21,F22,F37,F38) define how big of an AE
shot is delivered. Most of the time, this will get left alone, but
some of the more advanced guys might experiment with it.
Fueling Modes
• Decel Enleanment/Fuel Cut Off (DE/DFCO)
– When you lift your foot from the throttle, it
removes fuel.
– Why? Saves gas. No power is needed to spin
the motor on coast-down situations.
Fueling Tables
• The “Most Wanted”:
– Base VE -vs- RPM & MAP 3 BAR (EXTENDED,
Vaccum - 30 PSI) (F29x)
– Base Boost Multiplier -vs- Map 3 Bar (EXTENDED)
(F77x)
– Base Pulse Inverse Air Temp -vs- MAT (F31M)
– Base Pulse Constant -vs- Desired EGR (F28)
– PE AFR -vs- RPM (F61)
– A couple other players…
Fueling Tables
• Base VE -vs- RPM & MAP 3 BAR (EXTENDED,
Vacuum - 30 PSI) (F29x)
– The big Mac-Daddy… you’ll use this for 95%+ of
everything you’ll do with fueling. FAST, DFI, Bigstuff
have very similar VE tables.
– Allows you at add/subtract fuel at any MAP/RPM point.
– Covers all operating modes… idle, cruise, PE/WOT.
– Don’t exceed 99.6%... Table won’t do any good past
that
– Sidebar : F29, F30, and F29c –The legacy tables. F29
didn’t allow adjustment above 100Kpa before the
code59 modifications
Fueling Tables
• Base VE -vs- RPM & MAP 3 BAR
(EXTENDED, Vacuum - 30 PSI) (F29x)
Fueling Tables
• Base Boost Multiplier -vs- Map 3 Bar (EXTENDED)
(F77x)
– Provides a fuel multiplier vs. increasing MAP
– Note: Lowest entry in the table effects everything at or below that
level (84 Kpa), including idle and part throttle. Generally best to
not mess with that entry.
– Sorta redundant with the big F29x table, everything you can do
here you can also do in F29x. However, there are some times
where F77x is an easier way to do things. Examples:
• Alcohol injection; You can use F77x to pull fuel back after your alky
turn-on point
• Larger turbo installed, and you just want to shift the WOT fueling up
without messing with the rest of the F29x
• You want to move WOT fueling as a whole up or down due to a fuel
change, or weather conditions.
Fueling Tables
• Base Boost Multiplier -vs- Map 3 Bar
(EXTENDED) (F77x)
Fueling Tables
• Base Pulse Constant -vs- Desired EGR (F28)
– The “EGR” part is sorta misleading… F28 covers more
than just when EGR is functioning.
– In fact, it’s the global fuel constant. It moves all fueling,
across the board.
– Works as the “Injector constant”… this is what you
adjust when changing injector size.
– Once you get this “close” in terms of initial adjustment,
you won’t change it again.
– If you have EGR disabled the lowest entry in this table
is the only one that needs to be adjusted.
Fueling Tables
• Base Pulse Constant -vs- Desired EGR
(F28)
Fueling Tables
• Base Pulse Inverse Air Temp -vs- MAT
(F31M)
– This table allows you to adjust fuel for
increasing (or decreasing) air density.
– It also will allow you to add more fuel for really
HOT intercooler temps (ie, an intercooler
failure), which may save your motor.
– Generally isn’t something you adjust a lot,
although it may need to be tweaked a bit if
AFR creeps richer at higher intercooler temps.
Fueling Tables
• Base Pulse Inverse Air Temp -vs- MAT
(F31M)
Fueling Tables
• PE AFR -vs- RPM (F61)
– PE fuel table only is in effect under PE
conditions (WOT or significant acceleration)
– Table entries are displayed as AFR values, but
again, aren’t generally accurate with real AFR.
– Somewhat redundant with F29x.
– Doesn’t get used a whole lot, but can be used
if you need a quick way to change fuel at a
specific RPM at WOT, without changing fuel in
part throttle/cruise areas.
Fueling Tables
• PE AFR -vs- RPM (F61)
Fueling Tables
• Other Players– Fuel Injector Offset -vs- Battery Voltage (F92)
• Not messed with a whole lot, but you can often minimize idle
“surging” by reducing the spread between 11-14v.
– Cold Engine AFR -vs- Coolant (Closed Throttle) (F57)
• This is basically an idle fuel modifier when the engine is cold
and hasn’t gotten to full engine temp yet. (o2 enable temp)
– Cold Engine AFR -vs- Coolant Temp and MAP (F56)
• Same as F57, only for non-idle conditions
Fueling Tables
• F92
F56
F57
• Tool to make recommendations based on
data from TunerPro.
• You still need your brain… don’t
automatically believe it if something looks
fishy
• Can you really trust a WB 02 sensor?
• Again, smooth is good. You will often need
to smooth out Autotune’s
recommendations.
Questions
Ignition Timing
• What Is Timing?
– Putting it simply, Ignition Timing is when the
plug fires in relation to TDC of the cylinder
being fired.
– Why?
• The goal is to get the cylinder pressure peak to the
point where it can do the most good, without
inducing detonation.
– The Old-Timers called it “lead”, which is a
pretty good word for describing it.
Ignition Timing
• Common Misconceptions
– Timing alters fueling
• Not really, but it will make a Wide-Band Sensor think fueling has
changed. Late timing causes the burn to finish later, resulting in a
less complete burn, which shows up as less o2 in the pipe. (A “rich”
mixture, even though there really isn’t one)
– Too much timing causes detonation
• Not the case, at least, not directly. Advanced timing creates more
heat in the chamber, generally, and higher cylinder pressures. The
heat and pressure can lead to detonation, especially in the presence
of boost.
– I can copy somebody else’s timing table
• Only if you have the same heads, cam, pistons, quench distance,
ignition, intercooler setup, exhaust, and are burning the exact same
fuel from the exact same pump. Timing is very dependent on your
build.
– More Timing = More Power
• Not necessarily. Once the cylinder pressure peak gets past the point
where it does the most good, more timing starts to hurt things.
Tuning + Timing
• TunerPro/DM items involved– Spark Advance
– Knock Retard
– Knock Counts
• Not really timing related, but it helps to understand Knock retard
values
• Spark Advance
– Total amount of timing delivered
– Comes from the following major tables:
• Spark Advance -vs- RPM Vs MAP 3 Bar (F1)
• Spark Advance Adjustment -vs- Manifold Temp & Boost (PSI) 3 Bar
(F3)
• Base Coolant Advance Correction (F2)
• Others (EGR, Premium Fuel,Etc.)
Tuning + Timing
• Spark Advance -vs- RPM Vs MAP 3 Bar
(F1)
– The main table… you’ll be using this for 99% of
anything you’re doing with timing.
– Like the VE table, organized as an RPM vs.
MAP table
– Notable “gotcha”… when throttle is closed (like
at idle) only the bottom row (600) gets used,
regardless of actual RPM.
– Up to 4800 RPM… then what?
Tuning +Timing
Tuning + Timing
• Spark Advance Adjustment -vs- Manifold
Temp & Boost (PSI) 3 Bar (F3)
– A correction for increasing boost and MAT.
– Can be used to pull back timing in the event of
an intercooling failure
Tuning + Timing
• So, What do I do with it?
– Timing is more or less “trial and error” in absence of a dyno.
(Hopefully, not ERROR)
– The goal: Best power (torque) at a given RPM and MAP. At cruise
and part throttle, this is the timing where the least amount of
throttle position possible is needed to maintain that RPM.
– MPG generally increases when timing is optimized. Watching
BPW can help, but it takes a bit of practice knowing what to look
for.
– Detonation can happen at part throttle, and can silently ruin a
motor, so it’s better to stay conservative. If the motor seems to like
the timing you have at cruise/part throttle, stick with it.
– Plug checking is a good thing… speckles on the plugs means
you’ve gone too far.
Tuning + Timing
• So, What do I do with it? (continued)
– There’s an interaction with boost, timing, and fuel.
Changing one of the 3 will likely change the needs of
the other. This is why it’s soooo necessary to go slow
with tuning. If you’re thinking you’re gonna have this
done in a day or a few hours, forget it. Go slow, make
notes of your changes, learn from what you’re doing.
– Gas quality varies! A lot!
• The timing you can run today, may be lots different than the
tank you get tomorrow. Tune for the lowest grade street gas
you normally run, and watch your knock. A street gas tune is
no place for a push-it-to-the-limits tune.
– Alcohol-rich fuels tend to like more timing
– Bottom Line, you’re doing what the motor likes. Listen
to it.
Tuning + Timing
• So, What do I do with it? (continued)
– WOT (Wide open throttle) timing plays by the same
rules, although you get a bit more feedback in terms of
Knock Retard (KR) and audible knock.
– Start slow in the areas above 100 KPA. 10-14 degrees,
and work your way up. If you end up with much less
timing than that, you need to ask yourself… why?
– Watch knock retard like a hawk… if it knocks at all,
back off the throttle, and re-evaluate timing. Staying in
the throttle with continued knock will kill a motor.
– You’ll have lower timing (generally) at the bottom of the
shift point than you will higher up; knock is more likely
there.
ESC (Knock Retard)
• Another “closed loop”… an acoustic based system
for detecting knock, and retarding the timing to
prevent engine damage.
• Essentially a microphone listening to the motor
(you can actually record it and play it back on a
PC)
• ECM listens to sensor, and starts counting
whenever it detects something it thinks sounds like
knock. (Knock Counts)
• ECM uses the F6 (Attack Rate) and F7 (Recovery
rate) tables to translate counts to degrees
ESC (Knock Retard)
• F6 Table
• Reducing this “softens”
response to knock
• Generally don’t change it
much.
• F7 Table
• Increasing this speeds up
how fast KR is taken
away.
• If KR is still present long
after counts are gone, this
is too low.
ESC (Knock Retard)
• The magic question – is it real?
– You must assume KR is real until you’ve proven
otherwise.
• Look at where the knock occurs.
• Try some race fuel; if knock goes away, it was
real.
• There are many potential causes for knock… more
than can be listed here.
Questions
Boost Tuning
•
Overview: How it works (From a stock perspective)
– Solenoid control – Electronic bleeder valve
– Increased Duty Cycle (DC) bleeds more air from the Wastegate (WG) actuator,
which increases boost.
– Decreased Duty Cycle (DC) bleeds less air from the Wastegate (WG) actuator,
which decreases boost.
•
ECM takes a guess…
– ECM makes an initial guess as to where the WG needs to be (% DC-wise), then
from there adjusts the DC until the desired boost is achieved.
– ECM doesn’t start adjusting (or even the initial guess) until a hold-off pressure is
reached.
•
Other Stuff
– First-Time boost limiter (Gets shut off)
– Knock-based boost level reduction (Rarely used, although it’s not a bad idea)
– MPH boost cutoff (Usually also disabled)
Boost Tuning
•
Initialization WasteGate Duty Cycle
– The “first guess” the ECM uses; provides the base DC for the system to work from.
(WG DC in Tunerpro/DM data)
– F71_MPH; uses MPH
– F71; uses TPS
– Start low, work your way up
•
Desired Boost
– TPS vs. MAP- F70
– MPH vs. MAP –F70_MPH
– This is the desired boost that the ECM tries to achieve by raising/lowering the duty
cycle. (Desired Boost in Tunerpro/DM data)
•
Closed Loop Boost Mode Threshold High/Low
– Constant sets the “holdoff” point. WGDC is not applied until the “high” boost level
is reached, and DC is removed when lower than the “low” value.
– This can have a big effect on spool-up, as the wastegate is shut until this boost
level is achieved.
– Set it too high, and the WG can’t recover fast enough; boost spike or overshoot.
Boost Tuning
•
•
Positive Step Adjustment to Wastegate (KDCSTEP)
Negative Step Adjustment to Wastegate (KDCSTEN)
– How big of an adjustment the WG system makes each time it has to make a
correction.
– Make this too small, and boost control responds slowly; too fast, and the system
will go too far, resulting in up/down/up boost.
•
•
Closed Loop Wastegate Update - Negative Adjustment (KDCTIM8N)
Closed Loop Wastegate Update - Positive Adjustment (KDCTIM8P)
– These two work in conjunction with the above – They’re the amount of time
between adjustments. (Bigger number, more time between adjustments
– Like the step size, too slow results in not being able to react to boost fast enough,
but too fast results in up/down/up..
•
Negative Delta RPM to Stepup Boost (KWGDRPMN)
– WG DC resets to F71 value when this RPM delta happens (like on a shift)
– Useful for making big jumps in DC on shifts, or TCC lock.
Boost Tuning
• So, Where to Start?
– Know what boost level you’re going for.. (Whatever I can get show lack of
planning, and will likely make for a dead motor)
– Best to set the steps values to 0, at least initially.
– Then, set your F71_MPH to a low level, like 0-10%
– Slowly work F71_MPH up until you’re near or at your desired boost level.
You’ll likely have a few minor overshoots around the shift points and TCC
lock, but it should stay within 2-3 psi of where you want to be.
– Once you’re close with that, turn the steps value on low, like 1-3%. Set
the Update Rate adjustment fairly slow, like to .3-.5 sec. (Maybe slower)
– Make sure your F70(MPH) is where you want it, and go test. You should
see fairly tight control.
– High boost at gear switches? Make sure your DC is right at whatever
MPH your gear changes are.
– Some WG systems like Initialization DC only; closed loop update freaks
them out. If it works better with the steps at zero, leave it.
Questions