Code59 Tech Session

1. Code59 Tech Session

2. 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!

3. 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.

4. Thanks!

5. 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 one-time event. GM develops factory calibrations over a fairly long period of time.

6. 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

7. 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.

8. 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

9. 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.

10. 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..

11. 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.

12. 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!

13. 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.

14. 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.

15. Air/Fuel Ratio • AFR zone pic here?

16. 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)

17. 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.

18. 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!

19. Fueling Modes • Wide Band Closed Loop Fuel in Code59

20. 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.

21. 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.

22. 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.

23. 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…

24. 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

25. Fueling Tables • Base VE -vs- RPM & MAP 3 BAR (EXTENDED, Vacuum - 30 PSI) (F29x)

26. 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.

27. Fueling Tables • Base Boost Multiplier -vs- Map 3 Bar (EXTENDED) (F77x)

28. 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.

29. Fueling Tables • Base Pulse Constant -vs- Desired EGR (F28)

30. 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.

31. Fueling Tables • Base Pulse Inverse Air Temp -vs- MAT (F31M)

32. 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.

33. Fueling Tables • PE AFR -vs- RPM (F61)

34. 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

35. Fueling Tables • F92 F56 F57

36. Autotune • 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.

37. Questions

38. 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.

39. 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.

40. 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.)

41. 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?

42. Tuning +Timing

43. 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

44. 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.

45. 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.

46. 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.

47. 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)

48. 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)

49. 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. ESC (Knock Retard)

50. Questions