Who needs help with LNF's

[codename Bil Doe]

Disable tip-in limiting. Limit through other tables so you can back power off where you don't want it.

For SCCA T2 running the stock clutch is mandated. It'll handle 400whp fine. Just don't do clutch drops or hard launches. If you drag race it from a dig expect clutch problems.

Prop gain controls how quickly the turbo spools. OS table will override the PID tables, though. To increase responsiveness in between shifts raise the OS table in the low load areas. What you'll find is that the engine will spool the turbo and bleed it off at part throttle (<22% pedal) to be able to react quick enough to your demand. You'll hear the difference. Sounds like it's building up for a big rush. You'll also see the higher map readings at part throttle.

Adjust to your level of comfort. For DD you don't need to bump low load areas that high. Anything in the positive (+5-10) range will make it feel way better. Stock OS is -7 to -10 in the low load areas iirc.

I also suggest using one value for each load column. This is another trick into making the pedal response linear like an NA engine rather than exponential.

[califcarm]

I am starting from a GMS1 base:

OK, disabling Load Damping. And changing Load damping ETC Limit table all to 100% (which states it effect as disabling it).

Clutch - understood.

So my Prop gain is 1-2 at 7.3 psi delta, down to 0.1-0.08 at 1.5 psi delta at the other extreme. What kind of changes do you make to increase turbo response time?

My OS (Optimum spark I assume?) tables (4 of them) are GMS1 stock right now. That means in the 0 load column they range from 40-50. And over in the 200% load column they start at about 8 at 1000 rpm, and go up to anywhere between 25-45 depending on which of the 4 tables you are in. So I don't have any negative numbers at all in my OS tables. They are already positive to various degrees (Especially low load where they are 30-50 range). Not sure what to do with these?

TIA for continued help.

Another two questions to add:
What is the basic "Maximum Torque" table (that sits immediately above Max Air Load Torque). Its a small table that has only 1000-4000 rpm, and left axis says "none". I set them all to 100% since it seems this can only limit things where I probably do not want to.

Also, cat warm up: I am all stock parts, so leave it enabled is best?

[codename Bil Doe]

Start with stock tune and not the GM factory upgrade. Stock tune has fewer limiters.

Max torque keep max.

CAT warmup can be turned off. Drive slow until th car is up to temp.


Prop gain read up on under the PID thread. I won't tell you how to tune it. It's logical. If it's low in one spot but higher in the other...

OS table you need to read the thread on to understand how it works. You do have negative numbers across the table stock except high load columns.

Because you don't understand the OS and other tables I would suggest you make absolutely zero changes and run stock tune for a month or two and continously read the threads while logging to understand how and why things do what they do.

[califcarm]

just to make sure I understand the starting point:

OS = Optimum spark. Meaning the 4 tables under TORQUE MANAGEMENT---ENGINE---OPTIMUM SPARK?

Start with stock tune and not the GM factory upgrade. Stock tune has fewer limiters.

Max torque keep max.

CAT warmup can be turned off. Drive slow until th car is up to temp.


Prop gain read up on under the PID thread. I won't tell you how to tune it. It's logical. If it's low in one spot but higher in the other...

OS table you need to read the thread on to understand how it works. You do have negative numbers across the table stock except high load columns.

Because you don't understand the OS and other tables I would suggest you make absolutely zero changes and run stock tune for a month or two and continously read the threads while logging to understand how and why things do what they do.

[T-Man]

Another two questions to add:
What is the basic "Maximum Torque" table (that sits immediately above Max Air Load Torque). Its a small table that has only 1000-4000 rpm, and left axis says "none". I set them all to 100% since it seems this can only limit things where I probably do not want to.

That table is a torque reduction table used in conjuction with the Tq Mgt Cylinder Disable table but for more serious conditions. Read this -

http://www.hptuners.com/forum/showth...l=1#post146651

I personally left both tables stock as added safety precaution.

[califcarm]

That table is a torque reduction table used in conjuction with the Tq Mgt Cylinder Disable table but for more serious conditions. Read this -

http://www.hptuners.com/forum/showth...l=1#post146651

I personally left both tables stock as added safety precaution.

Thanks. I have put mine to stock. Want this daily driver to survive is something is sensed wrong by the PCM.

I have read a ton of threads here and on css.net and have never seen this question addressed:
The spark tables (at least starting with GMS1, and I think it is worse for the stock tables which I think only go to 200%) only go to load of 215% across the top. If this is load % as I see logged (same PID) then actual air load % is going way higher than 215, as high as 250% in a 4th gear pull at say 4000 rpm (23-24psi in this case, stock turbo).

I see that the timing I am getting seems to be what is in the tables for 215% (for corresponding rpm). I would think it must be just keeping the same timing from 215% to 250% load (and beyond if it goes there)?? If so, shouldn't we all be changing the axis for load % for spark tables to reach our maximum air load %? So that we have control over the high end range we are most concerned about? Right now I am guessing that I am getting flat spark response from 215-250% load, and only really have full control under 215% load.
Can anyone comment on this?

Another question I have not seen answered:
KR - Knock response registers a number for us (from the PID) that seems to correspond with degrees of ignition retard. But I can see in my logs that timing will not always be affected by the KR response I am seeing in the logs, meaning there is not always a dip in my timing curve when KR shows up. But then again, sometimes there is.
So when or how does the PCM decide that it is going to take the KR number and actually use it to retard timing?

[T-Man]

Thanks. I have put mine to stock. Want this daily driver to survive is something is sensed wrong by the PCM.

I have read a ton of threads here and on css.net and have never seen this question addressed:
The spark tables (at least starting with GMS1, and I think it is worse for the stock tables which I think only go to 200%) only go to load of 215% across the top. If this is load % as I see logged (same PID) then actual air load % is going way higher than 215, as high as 250% in a 4th gear pull at say 4000 rpm (23-24psi in this case, stock turbo).

I see that the timing I am getting seems to be what is in the tables for 215% (for corresponding rpm). I would think it must be just keeping the same timing from 215% to 250% load (and beyond if it goes there)?? If so, shouldn't we all be changing the axis for load % for spark tables to reach our maximum air load %? So that we have control over the high end range we are most concerned about? Right now I am guessing that I am getting flat spark response from 215-250% load, and only really have full control under 215% load.
Can anyone comment on this?

After you've had more time playing around with the controller, you can then start to adjust the axis columns. Not necessary until you're really trying to fine tune things with a greater understanding than what you have now. Just my humble opinion. In the simplest terms, in order to answer your question, no you don't NEED to. It can be helpful in many other areas though.

Another question I have not seen answered:
KR - Knock response registers a number for us (from the PID) that seems to correspond with degrees of ignition retard. But I can see in my logs that timing will not always be affected by the KR response I am seeing in the logs, meaning there is not always a dip in my timing curve when KR shows up. But then again, sometimes there is.
So when or how does the PCM decide that it is going to take the KR number and actually use it to retard timing?

This is still a fun question to answer - Simply put, this controller will register KR with the "slightest hint of a mouse fart".

[califcarm]

I will leave the axis for now. I seem to be able to get a nice 23psi tune with it as-is.

For KR, I just came from a 3sgte platform (Toyota 2L turbo) and had a J&S Safeguard installed (brilliant unit btw), which had a simple sensitivity knob on it so you can easily dial up and down what it interpreted as knock. Though a little trial and error with pump and race gas in the tank you could get it set safely, but with reality in mind so it would ignore engine noise and tip in knock (which does not matter since it is at low load). Wish we had such a thing. I guess your simple and eloquent mouse statement (LOL, love it) points to why the saying "all LNF's knock 2-3" came about. Unless the PCM actually pulls timing from the KR, then seeing some minor KR number (3 and under) on occasion is probably not detrimental (I have a full time knock monitor when I am not HP logging, so of course I would watch it carefully).

Thanks again for the help T-man and Bil.

[codename Bil Doe]

Tables extrapolate when you go off the end of them. When you exceed 215kpa it uses the value in the last known column and row.

Read up on false KR. I've posted many times about it. It's easy to eliminate and the process will make your car drive much smoother. It's caused by dips in timing when at constant pedal position or WOT. It can all be eliminated.

The regurgitated comment that all LNF's have kr and that's what they do is just regurgitated ignorance. I road race 23psi with up to 25? of peak timing depending on octane with no kr.

[MikeM173]

Bill is right on KR. As for changing the axis numbers, he is right and both of us have posted on that subject. One of my recent files I discuss the importance of changing row and column numbers when achieving ultimate smoothness in a table. When I have my computer up and running with the old HPT version, I will post a file I created for all of you to look at and ask questions. The file I'll post won't be my race files, but none the less it will show you guys a few things.

[T-Man]

Read up on false KR. I've posted many times about it. It's easy to eliminate and the process will make your car drive much smoother. It's caused by dips in timing when at constant pedal position or WOT. It can all be eliminated.

The regurgitated comment that all LNF's have kr and that's what they do is just regurgitated ignorance. I road race 23psi with up to 25? of peak timing depending on octane with no kr.

I never said that it was normal or that it couldn't be eliminated. califcarm was on the right track with looking at the registered KR and determining whether or not it's real. Eliminating it is going to be different for everyone. The only thing to correct my sporadic and false KR was Mike's suggestion to revisit injection timing and how my axis columns were setup in relation to my cam tables.

My comment about the controller wanting to register any slight thing it picks up as KR is not ignorance, it's fact. Saying that it is what it is and that it cannot be corrected is ignorance, that I agree.

[califcarm]

I never said that it was normal or that it couldn't be eliminated. califcarm was on the right track with looking at the registered KR and determining whether or not it's real. Eliminating it is going to be different for everyone. The only thing to correct my sporadic and false KR was Mike's suggestion to revisit injection timing and how my axis columns were setup in relation to my cam tables.

My comment about the controller wanting to register any slight thing it picks up as KR is not ignorance, it's fact. Saying that it is what it is and that it cannot be corrected is ignorance, that I agree.

Yes, it would be nice to know why/when the PCM decides to use the KR number to actually remove ignition timing or not. As of now, it seems that very low KR numbers do not always result in actual reduction in timing. So there is some other table or formula or limit to creation of actual timing reduction that we do not see or have access to.

[MikeM173]

I'm pretty sure I made a post that ends up describing KR completely. Maybe I haven't. I've been really busy and I still owe 5th injector tuning, so I'll add that to tables to write-up. Hopefully soon I'll be able to do it. KR is no mystery once you understand how it works. The entire car and tuning it should be rather simple. In fact:

The only reason these motors are a pain to tune is because people decide to run setups that are stupid. Certain intakes just plain suck. Too big of a 5th injector for the setup you have is dumb. Not having the correct controller for the setup you have is dumb. Don't even get me started on horribly choices turbos for a given outcome that is desired. So what is the problem you ask?:

People want a specific horsepower. Well I'm sorry to bust people's bubbles but horsepower means jack. Each dyno reads different. The day can change it. Other factors come into play. Heck your tire pressure can have effects on it. There is more to a properly done fast car then just numbers. Another issue people have is they want stock spool. Why? Why do people pick a turbo that offers stock spool that they know will blow their transmission if they don't tune it on a boost ramp. Why not just get a DIFFERENT TURBO!? Everyone is in a rush to spend money and they aren't in a rush to setup their car exactly how it should be done and they waste more money then they should and then they complain about the end result or blame the tuner etc. I'm sorry but most people need a reality check. That's why I go into detail about everything prior to starting any business with an individual and I usually like to try and get to them before they buy anything so I can help them out. There is so many variables that play into everything, and this is what makes tuning the frustrating part. I can tune well enough to have everyone done in no time and have the outcome they want. Why? Because I understand what can be done and what can't. I'm not try to showboat there, I'm simply saying, that is the understanding you want to have. It's amazing that I have given out the information I have and people are like well that doesn't work. How does it not work!? I have been tuning a long time and they always work. Ask questions!!! Try to learn. Stop reverting back. I didn't post this info for me. I'm done ranting and I apologize.

[T-Man]

Because of something personal that happened I've sold my coupe and my Solstice racecar is up for sale. Endurance racing now.

Because so many LNF questions have already been answered with other threads, I suggest posting links to other threads to answer people's questions when possible.

Because I don't need to keep it a secret any more I will be posting my tune and explaining the differences between what I do versus others and why.

I won't likely be on here much for answers, though I will try.

As for throttle hang, there are two causes. The first cause of throttle when on THROTTLE LIFT is in the integral gain table:

http://www.hptuners.com/forum/showth...LNF-PID-Tables


The integral gain controls how long the tb stays open. Stock settings cause it to hang open after lifting. You can adjust it tightly enough that the tb closes 1:1 with the pedal. Too high the tb will flutter fighting to close when wot. See thread.

The second cause of throttle hang is your OS table in the LOW LOAD/HIGH RPM area. Values too high there will cause throttle hang when shifting or in neutral.

My race tunes run very high OS values. My entire table is 25. A single value provides for linear pedal response regardless of rpm. A high value gives me instant throttle response everywhere. Very important to remove all lag for racing. But, if you try revving the engine in idle it will cause throttle hang. You shouldn't do that in the first place. I DD this race tune, so it's no issue unless you clutch in and idle at high rpm or rev the engine.

Thanks for the reminder Bill. I believe the Cobalt's integral gain is a bit more aggressive than the Solstice/Redline table both stock and GMS1. I've had no luck in messing with that one but thanks to your suggestion on going back and looking at the high rpm/low load areas in OS, I think I've fixed my slight throttle hang issue I was having.

[codename Bil Doe]

Cobalt SS seems to be more responsive/aggressive/generate better numbers because of less driveline loss with the FWD methinks.

I'll post my tune when my car sells. I run integral gain table at all "1.000" to keep it linear 1:1 response to the pedal. I'll explain it all once I post the tune. Many tables like wgdc can go over 1.000 or 100%, but they become multipliers. Setting something to 150% makes it react with 1.5x the input.

High rpm/low load high values give you instant boost response after lift but will cause throttle hang in neutral. Balance of all the tables, of course. Can't change one without affecting others.

KR comment wasn't based on your post. I just hopped on and saw calif's question. Didn't even read your post. Just the common thing by a lot of other people to regugitate what they read on forums with no understanding of what they are talking about.

I'm only hopping on here to answer some questions and help until my car sells.

[T-Man]

Cobalt SS seems to be more responsive/aggressive/generate better numbers because of less driveline loss with the FWD methinks.

I'll post my tune when my car sells. I run integral gain table at all "1.000" to keep it linear 1:1 response to the pedal. I'll explain it all once I post the tune. Many tables like wgdc can go over 1.000 or 100%, but they become multipliers. Setting something to 150% makes it react with 1.5x the input.

High rpm/low load high values give you instant boost response after lift but will cause throttle hang in neutral. Balance of all the tables, of course. Can't change one without affecting others.

KR comment wasn't based on your post. I just hopped on and saw calif's question. Didn't even read your post. Just the common thing by a lot of other people to regugitate what they read on forums with no understanding of what they are talking about.

I'm only hopping on here to answer some questions and help until my car sells.

All good my friend. Hard to have a regular convo through text without it coming across wrong such as my post.

I truly believe that the PID tables are close with the Delta's but the OS tables is where it's at.

[codename Bil Doe]

You are dead on. OS is king of all tables. That's why I said for fun and understanding in the OS thread to have people set their OS tables to all -10 and see what happens. You can have the WG 100% and not see 2psi up to redline.

[T-Man]

You are dead on. OS is king of all tables. That's why I said for fun and understanding in the OS thread to have people set their OS tables to all -10 and see what happens. You can have the WG 100% and not see 2psi up to redline.

Fair assumption to say that our OS tables are a lot like the driver demand torque tables that GM and Ford are using in their new controllers?

[codename Bil Doe]

Not really. GM's ecu is much more intuitive once you understand it. They have straightforward comparisons without having an all-powerful illogical table. For ex, airmass exceed max airmass allowed? Cut power. Pretty simple. Just have to find out which tables are interrelated.

Driver demand does not need to be modified. I would make it linear for linear pedal response along with similar mod to other tables. Focus on changing max limits and not trying to demand 400% of a lower limit.

[kylelv8]

I've been trying to tune my MAF for the Hahn intake that came on my car because the guy who tuned apparently couldn't. I was getting around -30% STFT and LTFT pretty much all the time. I used the method that BYT and CSSOB posted but I think since most of my pids are reading in the negatives, it's not correctly adjusting them, if that sounds right. Honestly, i'm new at this and I'm not trying to make money from anyone, so I'd appreciate any heads up I can get. Plus, even with very mild or stock spark tables and cam tables, I've been getting KR all over the place. The guy that tuned my car (before I bought it) had the PE tables set up at .77!Untitled.png