Code59 Tech Session

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Code59 Tech Session
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Whats 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!

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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 wont.
• 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.

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Thanks!
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Moving Forward

• Ive got all the stuff, and its 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 theyre not a one-time
  event. GM develops factory calibrations over a
  fairly long period of time.

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What is a Good Tune?

• A good tune idles well, or as well as can be
  expected given the engine build youre working
  with.
• A good tune drives nicely it doesnt die when
  you back up, or pull up to a stop sign, or turn
  the A/C on.
• A good tune is smooth. It doesnt jerk/buck at
  part throttle or WOT.
• A good tune will get respectable fuel economy.
• 10 MPG isnt 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, its
  not at the edge all the time)
• A good tune makes good power

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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 dont need to know anything
  about the above to get the fueling right.

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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, its 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

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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 youre either coasting or
  youre 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, its whatever
  the outside air pressure is, plus boost.

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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 its doing. So, it needs
  more fuel to do that work.
• How much fuel? Well get into that in a bit..

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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.

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Air/Fuel Ratio

• So what is the proper Air/Fuel Ratio(AFR)? Whats
  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!

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Air/Fuel Ratio

• AFR zones
• Idle
• Generally in the 131 -151 range, although some
  big cam motors will like even richer (numerically
  lower) mixtures to idle smooth.
• Cruise/part throttle
• 13.51 161, 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.

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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 youre running.
• Max power generally happens in the 12.3-12.91
  range for boosted engines, although you will
  rarely run one that lean unless youre pushing
  the limits and dont care about blown engines.
• Street Gas tunes end up being in the 10.9-11.91
  range, generally.
• Race Gas tunes end up in the 11.2 -12.51 range
• Alcohol Injection tunes end up in the high
  101-low 111 areas, although there is a wide
  difference depending on how your system is set
  up.

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Air/Fuel Ratio

• AFR zone pic here?

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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)

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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
  dont 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 isnt
  using any feedback from the sensor its just
  delivering a fixed amount of fuel.
• Closed Loop only happens at part
  throttle/cruise/idle it doesnt occur at WOT or
  PE.

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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 14.71
• 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!)
• Its 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 dont.
• Dont try to use closed loop as a crutch for a
  bad tune. 99 of your tuning work will be done in
  open loop!

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Fueling Modes

• Wide Band Closed Loop Fuel in Code59

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Fueling Modes

• Power Enrichment (PE)
• Like the name suggests, PE is in effect only when
  a heavy foot is applied.
• Doesnt have to be full WOT, although PE is in
  effect at WOT. Its 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 wont match up to real AFR. In the end,
  theyre sorta arbitrary constants
• While it sounds like this table would get used a
  lot, in reality, most tunes leave this alone.
  Well get into why, a bit later.

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Fueling Modes

• Acceleration Enrichment (AE)
• Sorta like the accelerator pump shot on a carb
• Why AE?
• Theres 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 its 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 dont need a
  whole lot of AE. (It doesnt 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.

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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.

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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

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Fueling Tables

• Base VE -vs- RPM MAP 3 BAR (EXTENDED, Vacuum -
  30 PSI) (F29x)
• The big Mac-Daddy youll use this for 95 of
  everything youll 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.
• Dont exceed 99.6... Table wont do any good
  past that
• Sidebar F29, F30, and F29c The legacy tables.
  F29 didnt allow adjustment above 100Kpa before
  the code59 modifications

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Fueling Tables

• Base VE -vs- RPM MAP 3 BAR (EXTENDED, Vacuum -
  30 PSI) (F29x)

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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.
  

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Fueling Tables

• Base Boost Multiplier -vs- Map 3 Bar (EXTENDED)
  (F77x)

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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, its 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 wont change it again.
• If you have EGR disabled the lowest entry in this
  table is the only one that needs to be adjusted.

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Fueling Tables

• Base Pulse Constant -vs- Desired EGR (F28)

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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 isnt something you adjust a lot,
  although it may need to be tweaked a bit if AFR
  creeps richer at higher intercooler temps.

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Fueling Tables

• Base Pulse Inverse Air Temp -vs- MAT (F31M)

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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, arent generally accurate with real AFR.
• Somewhat redundant with F29x.
• Doesnt 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.

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Fueling Tables

• PE AFR -vs- RPM (F61)

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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 hasnt 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

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Fueling Tables

• F92 F56 F57

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Autotune

• Tool to make recommendations based on data from
  TunerPro.
• You still need your brain dont 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 Autotunes recommendations.

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Questions
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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.

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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
  isnt 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 elses 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.

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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.)

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Tuning Timing

• Spark Advance -vs- RPM Vs MAP 3 Bar (F1)
• The main table youll be using this for 99 of
  anything youre 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?

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Tuning Timing
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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

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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 its 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 youve gone too far.

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Tuning Timing

• So, What do I do with it? (continued)
• Theres an interaction with boost, timing, and
  fuel. Changing one of the 3 will likely change
  the needs of the other. This is why its soooo
  necessary to go slow with tuning. If youre
  thinking youre gonna have this done in a day or
  a few hours, forget it. Go slow, make notes of
  your changes, learn from what youre 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, youre doing what the motor likes.
  Listen to it.

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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.
• Youll have lower timing (generally) at the
  bottom of the shift point than you will higher
  up knock is more likely there.

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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

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ESC (Knock Retard)

• F6 Table
• Reducing this softens response to knock
• Generally dont 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.

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ESC (Knock Retard)

• The magic question is it real?
• You must assume KR is real until youve 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.

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Questions
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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 doesnt 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 its not a bad idea)
• MPH boost cutoff (Usually also disabled)

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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 cant recover fast
  enough boost spike or overshoot.

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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
  Theyre 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.

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Boost Tuning

• So, Where to Start?
• Know what boost level youre 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 youre near or at
  your desired boost level. Youll 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 youre 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.

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Questions