LNF TUNERS: Learn, share and make hp HERE!

[gmtech16450yz]

OK everyone, I believe this is a new era in tuning our little LNF's, and in this thread I'm attempting to break down some of the barriers keeping the ENTIRE LNF community from sharing and learning.

On this platform, as on many others, there seems to be a little too many secrets, stolen ideas and too much emphasis on selling tuning discoveries instead of sharing. Most of us on this forum are tuners, some doing it for money, others just doing it on their own cars for the fun of learning and driving. For those doing it for money, if you really want to take care of your customers and give them the best tune possible, you need to keep up with all the discoveries and ideas. The best way to do that is to share openly, that way EVERYBODY benefits. Don't be so wound up on worrying that someone will steal your customers, or your ideas. For the most part, your customers are your customers, meaning if you take care of them they shouldn't leave you anyway. And the truth of the matter is, NO ONE KNOWS EVERYTHING THERE IS TO KNOW ABOUT TUNING. If you know everything, you're done learning.

Nick (BackyardTurbo_FTW), and Tom (Iam Broke) have been amazing in sharing what they've learned. (As have many others, sorry I didn't name everyone.) When I first got my Sky Redline, the first and most informative thread I read was Nick's "LNF Tuning Guide". This thread is following in the spirit of that thread, and his other guide threads. (I'll post those links at the end of this.)

Tom's work and sharing on E85 has resulted in dozens of us burning corn! I have learned quite a bit from him. Again, this thread will hopefully tie all these ideas together.

So go for it guys! When I get a chance, I will post many of my own discoveries I've had on the LNF's. Cam and ign timing, torque and boost control, dfco, and I think one of the most important, throttle control. Some of these I've come up with on my own, some I've gathered info from others and expanded on further. We needed a place to share these ideas, hopefully this will help.

If you can, try to keep on subject so this thread doesn't get huge and hard to navigate. Maybe it will just end up being a place with links to where other discovery or discussion threads are. Whatever works.

Thanks guys!

[gmtech16450yz]

Here's some links to some of the best LNF threads...

Lots of good info on Cat Warmup Delete and Cam Timing...
http://www.hptuners.com/forum/showthread.php?t=33878

Torque Management Inj Disable table and it effecting DFCO...
http://www.hptuners.com/forum/showthread.php?t=28714

Basic LNF/Bosch ECM torque based engine management info...
http://www.hptuners.com/forum/showthread.php?t=20339

Nick's LNF Tuning Guide...
http://www.hptuners.com/forum/showthread.php?t=26232

Maf tuning...
http://www.hptuners.com/forum/showthread.php?t=26756

Tom's E85 thread...
http://www.hptuners.com/forum/showth...e85+experiment

The latest tables discussions...
http://www.hptuners.com/forum/showthread.php?t=33449
http://www.hptuners.com/forum/showthread.php?t=33467

Idle and cold start info...
http://www.hptuners.com/forum/showthread.php?t=36029
http://www.hptuners.com/forum/showthread.php?t=35943

More good info from Tom (Iambroke) about 3bar maps...
http://www.hptuners.com/forum/showthread.php?t=35860

I'll add more later or let me know if there's other good ones we should keep handy.

Sorry to neglect this thread guys, I kinda forgot about it actually! Here's some new links to threads with lots of good info-


I held off posting this info up for quite awhile. It looks like a few frustrated guys probably wished I waited longer! It is possibly the most important and valuable thread I've done though...
http://www.hptuners.com/forum/showthread.php?t=39660

This one is info on the config file I use. I believe it's one of the first steps to understanding logging on the LNF. You REALLY have to have a good scanner setup to be able to see what's going on in all the areas of the tune...
http://www.hptuners.com/forum/showthread.php?t=39748

Here's some cool work Silverbullet did on launch control for the LNF...
http://www.hptuners.com/forum/showthread.php?t=39626

[Bill@HPTuners]

stickied.

[fr0stb1t3]

Hey Bill, if we populated the data would you be willing to host a wiki on you the HPT site? I've been thinking for a while that it is truly the best way to organize all the data we have. The only downside I can see is that it'd need some light moderation since people tend to disagree in some of the other sections of the forum

[Iam Broke]

Thanks John & Bill, I'll post further info as we figure it out in this thread.

Just getting started on this, so far...

http://www.hptuners.com/forum/showpo...4&postcount=17

If you guys have been boosting 24 psi, cut your DAL's or you will spike 27 psi or so initially when upping the turbo tables.

[gmtech16450yz]

Thanks Bill!

Tom, here's my second attempt at boost control. I haven't actually even loaded this yet, but I think this will get me close to a flat curve. Before these new tables, I was having pretty good luck controlling boost spike with "Max Engine Torque vs. RPM vs. Gear". What I did last night was put "Duty Cycle Correction" down to 70% in the full load areas around the 3700rpm boost spike. It most definately limited boost, there was a pretty good drop right were I had the table at 70%. I went further than I thought last night specifically to make sure I was making an effect, and 70% was farther than I needed. These screen shots are what I think will keep my 3700rpm spike in check. What will be interesting to figure out is are we better controlling boost and throttle with the max engine torque/gear table or with the actual boost control tables? I like the idea of having different boost in different gears so I'm not sure I want to totally loose that by zeroing out that table. So what I also did was to raise those slightly, but not all the way to 100%. I was only really limiting boost and throttle in 3rd, 4th and 5th, and only around the 3700 area anyway. We'll see!

On to injector timing next, has anyone made any progress there? I also raised fuel pressure from 15 to 16MPa, or 2320psi. My reasoning there is a little higher should help but not hurt. If GM thinks 2200 is safe and fine for the pump, inj, lines, regulator, etc, than I would certainly think their safety margin would certainly include up to 2300psi being OK.

I also wonder if we should be changing "Combustion Pressure Multiplier" since with raised boost levels combustion pressures would certainly also be higher? Hmmm, just looked and the GM Stage Tune didn't change that table on my OS so maybe that theory is faulty.

Remember guys, as long as it's a table that won't do damage or cause problems, always try big changes at first to get an idea of what it's doing. Take that boost duty cycle correction table and put 50% in the 3500 to 4500rpm rows and you'll immediately see what it's doing.

[Iam Broke]

Certainly a different approach that I was considering, I just took off the limits by going to 100% and was adjusting the DAL's for boost. I did decrease the integral gain on the controller PID above 6k but haven't tried it yet. The stage file really ramped it in up top.

[gmtech16450yz]

Certainly a different approach that I was considering, I just took off the limits by going to 100% and was adjusting the DAL's for boost. I did decrease the integral gain on the controller PID above 6k but haven't tried it yet. The stage file really ramped it in up top.

Yeah I'm still thinking unless we have trouble between desired and actual, I'm not sure we have to change the PID gain tables. As long as proportional max has the ability to go to 95% that is, that's why I changed that.

This is from last night, 16psi and 7300! Can you hear that little K04 screaming "help me, help me"!
If you look at the far left on the desired boost you can see where it didn't go straight up to 95%. That was because I had 70% desired up to 4500rpm so when I went full throttle it actually started boost DC at 70%, then ramped up to 95%, exactly what I had put in the tables.

[T-Man]

I'm going to adjust the WG correction table and work the PID gain tables, seeing that's what GMS1 was developed around, in order to achieve more boost. I'm going to mess with it a bit and post up here shortly. Plan is to modify the WGCT, PID gain and put DALs back to stock and start adjusting from there.

Tom,

I don't think you need to adjust the A & B tables as those look to be part of the knock suppression feedback loop. I'll bet those two tables work in tandem with the Injection disable table... Just a theory though.


Thanks again to Tom, John and of course thanks Bill for the sticky!

[Chris@HPTuners]

the combustion pressure tables are only used when the GDI is injecting during the compression stroke, probably a bad name from me sorry, but its the multiplier for the combustion chamber pressure during the compression stroke. It is an estimation that is used to calculate the injector pressure delta during these double pulse modes.

I looked for a PID for the current GDI Mode for the scanner but i couldn't find one.

Chris...

[T-Man]

Here's some fuel timing charts for the different modes that Aaron (405HP Z06) posted with regard to the crank shaft revolutions in degrees:

[gmtech16450yz]

the combustion pressure tables are only used when the GDI is injecting during the compression stroke, probably a bad name from me sorry, but its the multiplier for the combustion chamber pressure during the compression stroke. It is an estimation that is used to calculate the injector pressure delta during these double pulse modes.

I looked for a PID for the current GDI Mode for the scanner but i couldn't find one.

Chris...

Ahh Ha! You did put in there "for injection during the combustion cycle", that should have told me it wasn't for hom single pulse during intake stroke. Thanks for peeking in here and helping us out Chris!

Hey are there any hints or ideas you know of by finding and looking at these tables that might help us? Like what's the difference between "Hom Single Low" and "Hom Single High"? Except for saying low and high, the descriptions are the same.
Just looked again, I see the "Charge Threshold" between low and high tables on my OS is set to 0.10, with the range being 0-1. Stupid question but 0-1 what? Does this have to do with boost levels? Anyone?

Good find T-Man. I wonder if there's anything in these new tables that we can effect cold start cat warmup in a roundabout way. Sure would be nice to at least be able to control the ign timing during cat warmup. There's nothing in there for changing Stratified injector timing, if there was I'm guessing maybe with that we could move the inj timing back to intake to control cat warmup indirectly. Chris if you happen to stumble across any cat warmup stuff that would be awesome, even just a plain old delete.

[Iam Broke]

I'm going to adjust the WG correction table and work the PID gain tables, seeing that's what GMS1 was developed around, in order to achieve more boost. I'm going to mess with it a bit and post up here shortly. Plan is to modify the WGCT, PID gain and put DALs back to stock and start adjusting from there.

Tom,

I don't think you need to adjust the A & B tables as those look to be part of the knock suppression feedback loop. I'll bet those two tables work in tandem with the Injection disable table... Just a theory though.


Thanks again to Tom, John and of course thanks Bill for the sticky!

Yeah I thought maybe that it wasn't needed but was covering all bases on my first feeble attempt.

Be careful cranking the prop gain too much, it'll start to oscillate.

[Chris@HPTuners]

in the LNF code you only have Hom, Hom Double (same as Hom Strat i guess), Hom Knock and and a High Pressure Start mode (which i didn't include). You don't have any of the others.

The charge threshold is the charge motion valve position (for switched manifold), i will update the help info on this. It looks like manifold position is set to 0, so you should always be running from the Low table.

[T-Man]

in the LNF code you only have Hom, Hom Double (same as Hom Strat i guess), Hom Knock and and a High Pressure Start mode (which i didn't include). You don't have any of the others.

The charge threshold is the charge motion valve position (for switched manifold), i will update the help info on this. It looks like manifold position is set to 0, so you should always be running from the Low table.

You the man Chris! Thanks buddy!

Edit-
High Pressure Start mode or Strat?


In looking at the Injection Angle Hom Single Low, since it's based on load and rpm in relation to the angle of the crank shaft, wouldn't we want to lower the numbers in the areas where we would want to inject fuel sooner?

[Ch1ck3n]

Mannn, you guys are going to discover evverything before I even get a chance to try anything on my car..

Haha, hope there's some discoveries left to share when I get my car back from the body shop.


EDIT: One thing I did notice is while comparing the stock tune to GMS1 is that the X axis values on the Proportional Max table are ramped to 23.2psi instead of 17psi that the stock table has.

Not really sure if it would cause any changes, since I don't have my car

[Iam Broke]

You the man Chris! Thanks buddy!

Edit-
High Pressure Start mode or Strat?


In looking at the Injection Angle Hom Single Low, since it's based on load and rpm in relation to the angle of the crank shaft, wouldn't we want to lower the numbers in the areas where we would want to inject fuel sooner?

The fact that the stock numbers increase with load leads me to believe the opposite.

[gmtech16450yz]

In looking at the Injection Angle Hom Single Low, since it's based on load and rpm in relation to the angle of the crank shaft, wouldn't we want to lower the numbers in the areas where we would want to inject fuel sooner?

Look at the chart you posted T-Man, higher numbers mean more advanced. As you can see from the chart, 360 is the earliest you would want to inject on the intake stroke, that's why it maxes at 360. And 180 would then be the latest, unless it's a double pulse or stratified mode.

[T-Man]

Gotcha. I was looking at the chart wrong.

Thanks fellas.

[Chris@HPTuners]

the angles are referenced to degrees before TDC