looking for some lnf tune input

[scdude]

I was wondering if anyone experienced wanted to look over my 2009 lnf tune.

[cobaltssoverbooster]

i posted a file with recommended changes to torque management, cats, cams, ignition.
*this will be a compare file, do not flash it in directly.
**do not change your maf or dal or boost solenoid settings, those look fine. you might need to adjust them again after this flash to lock the boost in appropriately but you have good starting values here.
Suggested starter.hpt

[npaz]

Can you tell me the purpose of your cam changes on your starter tune file? Can I try them out without changing anything else? OK on Kappa?

[scdude]

thank you sir for your suggestion, I do appreciate it. but I am also curious what those changes to the cams change in the cars behavior?

[scdude]

side notes**
the car is 100% stock and is on 91 octane. so I will not be touching the cat over temp stuff.

[scdude]

This is what I have after some tuning, the car just cant see more timing at wot without hitting kr.
2009 with suggested changes.hpt

[npaz]

I'll chime back in as well. I also noticed the Main Spark and Optimum Spark are quite a bit different from GMPP (my usual reference for seeing what is being changed in a tune). Can you give any info on what those changes were for? Thanks!

[cobaltssoverbooster]

i submitted a file with std ignition for a boosted DI Ecotec. 14* is just about max on a kappa chassis, some people are able to squeeze a little more out but for safety reasons that just about max.

cam changes are a standard file swap which uses the lower overlap settings from the stock gmpp cold cam tables as a start towards shifting cams for better mid-range response and mpg increases.
the base idle tables are defaulted to a value that forces the cams to physically rest on the phaser units stop block which is commonly referred to as the "parked position" of the phaser. this parked position keeps the cams at maximum separation which helps keep the idle smoothed out.
as you will notice the cam tables are fixed to match each other on the the main tables. this prevents 4 tables from providing camshaft position data for the ecu to choose from and forces the ecu to command one 3d table set of camshaft data. this further adds to the ecu stability and helps smooth out other tables.


there is a long lecture on optimum spark settings, i just fixed them to a std starting value of an offset of +10. until you have read the lectures on it and understand the boost pid tables and how the ecu maps torque effectively, its not really something i would worry about. opti spark is a topic that requires a deep understanding of the ecu's coded logic parameters. this is the main reason i offer a base file with fixed values and dont talk about opti spark in length with forum members. its not an easy subject for myself to just teach.

[npaz]

Once again Overboost, you are the man.

Improved gas mileage doesn't really matter to me, but more midrange punch is always good. Will the settings help or hurt at 5300ft?

I've read every LNF tuning thread on this forum and grasp some of the spark/optimum spark tables. So you are saying you just subtracted the main spark tables from the Opitimum tables and added +10 to all. Which would be adding more urgency to all values? Then added the spark tables back in?

I noticed that the base Spark Tables are modified as well, can you mention what you did there and why?

Can the spark and cam tables be used with no other changes to the tune?

Finally, as usual I will ask - any benefit to these changes at 5300 ft elevation? : )

[cobaltssoverbooster]

yes there is always a benefit to changes. these dont really need the overlap that gm programmed them to run at. therefore i took them out.

as i mentioned in a previous post i ran the ignition up to the max safe value i have seen over and over again. the rest of the table is a blend to keep it fairly smooth.

what i did to optispark is base spark copied and pasted into opti spark then add 10. i will not discuss optispark, as i said its not something im good at teaching.

[npaz]

Hey CSSOB, I forgot to ask - are your Suggested starter tune spark and cam tables ok to use with 91 Octane? Thanks!

[cobaltssoverbooster]

yes they are designed for 91. i never made a file compatible for any fuels rated lower that 91 octane.

[npaz]

I only can get 91 around here. : (

Unrelated question CSSOB - Do you use cell count to filter out KR or Boost? Can't find any info on here.

I have a few random 3-5 hits in a cell on KR. Should I just filter them out? Also, I'm getting some .3 to 1 second boost readings that are high and out of range (2 to 5 psi). Usually after I do a WOT and then get off the gas rapidly. Should I ignore that because it's so short a duration, or does it mean something? Thanks!

[cobaltssoverbooster]

no when i question something i switch the histogram to "last" or "actual" value and scroll through using the time bar and play button to check events out.
i only filter cell count for fuel trims.

i always had spikes after let-off because i never upgraded the bpv or re-programmed its parameters. there is a way to remove some of it by filtering out negative slope activity on the tps signal.

[npaz]

Thanks for the reply! So should I worry at all about that let-off boost spike? It seems pretty harmless at a second or less in duration.

[cobaltssoverbooster]

I never did.
4 years on a completely stock setup at 24 psi. Boost spike was 26-27 psi.

[npaz]

I've done the Optimum Spark Tables at a flat +10, still using the stock timing tables for now. I also added your cam timing tables. I like it! Much more linear feel and reduced some KR as well. You are the the man!

Can you tell me where the boost can be, or should be pushed up? I'm hitting 24.17 at 4520 rpm. Around that though is a lot lower:
3520=18.66 5000=20.69 5520=18.95 6000=19.82 OK to try and push all these up as well?

You appear to be the only one still around on this forum that knows the LNF and is willing to talk about it. Guess I showed up years late to the party! : )

[cobaltssoverbooster]

i used to get 20 psi by roughly 2200 and i called that good. i ran 24 psi by where ever it could produce it but i didn't run full ignition until 4200-4400 rpm. 20 psi ish is about normal around 5800 rpm. that's just about all the stock unit can put out flow wise.

the other people come in here but many of them have shops and once they know what they are doing they continue to go about business instead of share to learn because time here is money wasted after a certain point. The other few switched platforms and are likely not willing to recommend advice due to time out of practice. Too be honest i'm getting close to my time out of practice point. i'm slowly forgetting the benefits to certain tables plus i made a platform shift to 2jz, RB26, and LSX. I spend more time reading about those than i do here now.

[npaz]

CSSOB - Graphing my boost numbers vs speed shows that I'm only making 24 psi of boost when I hit 4th gear at 75-80 mph. All other gears are lower. What kind of DAL numbers were you running in Reno to get your boost levels that high from 2200 to 5500? Could you post or pm me a sample DAL and WGDC maps to see where to go with this? Also, should I raise the Optimum Torque Table to go along with raising the other two? I'm slowly messing with these, but not sure how high to go.

Does anyone else out there find boost vs mph useful? I started looking at it to see what is happening around my shift points, it seems like the best way to actually see what your boost is doing.

[califcarm]

CSSOB - Graphing my boost numbers vs speed shows that I'm only making 24 psi of boost when I hit 4th gear at 75-80 mph. All other gears are lower. What kind of DAL numbers were you running in Reno to get your boost levels that high from 2200 to 5500? Could you post or pm me a sample DAL and WGDC maps to see where to go with this? Also, should I raise the Optimum Torque Table to go along with raising the other two? I'm slowly messing with these, but not sure how high to go.

Does anyone else out there find boost vs mph useful? I started looking at it to see what is happening around my shift points, but seems like the best way to actually see what your boost is doing?

Boost vs rpm is what you want to be looking at. RPM is the increment by which all your tuning parameters are made. I did not choose to tune with DAL. I set DAL at the high end of reasonable (255) for most high load cells/rpm points. Then used the WGDC to tune the boost curve. Found that easier than trying to play with both DAL and WGDC at the same time since they both affect boost. Attached is my tune if you want to look it over.022317 califcarm 2009 cobaltss.hpt