poormxdad's (as directed) new noob questions thread
#43
CLI Initial Values Table Conventional Wisdom
Gents,
Been getting the cold shoulder for a number of days now. Maybe someone would be willing to chime in, in the spirit of brotherhood and world peace and such...
I've been looking at several different tunes and noticed that although ALL the CLI Initial Values Tables of the different tunes had numbers that increased as rpms increased, some had values that increased as the temp increased, and some had values that were highest when the temps were lowest in the table--the values decreased as temp increased.
It seems like it should be one way or the other, that the theory isn't changed by individual car setups. But, I've been wrong about stuff before.
Someone should easily be able to put this to bed.
Thanks,
Been getting the cold shoulder for a number of days now. Maybe someone would be willing to chime in, in the spirit of brotherhood and world peace and such...
I've been looking at several different tunes and noticed that although ALL the CLI Initial Values Tables of the different tunes had numbers that increased as rpms increased, some had values that increased as the temp increased, and some had values that were highest when the temps were lowest in the table--the values decreased as temp increased.
It seems like it should be one way or the other, that the theory isn't changed by individual car setups. But, I've been wrong about stuff before.
Someone should easily be able to put this to bed.
Thanks,
Last edited by poormxdad; 07-08-2017 at 01:23 PM.
#45
FWIW, my operating theory was that the initial values should be the highest where the RPMs are below the target idle RPM and as the IATs are further away from (what I consider to be) a "stable" temp. Then the values should trend towards the idle valve closed duty cycle. My concept being that, when the IATs are cold, I want the idle to start a bit high and then settle down towards the valve closed setting. Likewise, if the RPMs are low, coming into the idle state, I want the CL initial value to start high and come down to the CL valve setting.
These are my settings, and my CL Idle Valve Closed value is 23.1% and my idle target RPM is 1000;
These are my settings, and my CL Idle Valve Closed value is 23.1% and my idle target RPM is 1000;
#47
You're almost right. The settings from the table outside of the range specified stay constant. So...if the IAT goes above 110 degrees, then the values set in the top row remain constant, no matter what the temp rises to. Likewise, if the RPMs start above 1800 then the settings in the left-most column remain constant.
The table that I have provides settings for a range of RPMs and IATs that caused the most problems for me, where I live. For that, it means that temps below 110 degrees and RPMs between 500 and 1800 are the most significant and where I need to pay attention to the initial values.
YMMV
The table that I have provides settings for a range of RPMs and IATs that caused the most problems for me, where I live. For that, it means that temps below 110 degrees and RPMs between 500 and 1800 are the most significant and where I need to pay attention to the initial values.
YMMV
#48
This is very interesting. I did what I thought to be the standard procedure. On a cold day early in the Spring I let the car warm up then did the idle valve test. I filled in the numbers on the 55 degree line and put those same numbers in other temp lines as well. Then, a couple of months ago on a very warm day, I did the test and filled in the 90 degree line. Then I interpolated the table. My table reflects needing more valve for higher temps. There are other tunes out there with similar tables, but some are essentially opposite. You've taken a different approach.
What frequency do you have the valve set at?
How do you know this?
Thanks much,
What frequency do you have the valve set at?
Thanks much,
#50
This is very interesting. I did what I thought to be the standard procedure. On a cold day early in the Spring I let the car warm up then did the idle valve test. I filled in the numbers on the 55 degree line and put those same numbers in other temp lines as well. Then, a couple of months ago on a very warm day, I did the test and filled in the 90 degree line. Then I interpolated the table. My table reflects needing more valve for higher temps. There are other tunes out there with similar tables, but some are essentially opposite. You've taken a different approach.
What frequency do you have the valve set at?
How do you know this?
I don't know if the difference is NA vs NB, or 1.6 vs 1.8 - might be worth some comparisons...
#51
Retired Mech Design Engr
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Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,012
Total Cats: 859
here are my settings. Based on where valve settles at the MAT temps. Some are extrapolated because I have never really seen them, but this gives my typical shape. Others, like 1500 RPM and 75Deg will never occur, because my RPM CLT curve is such that I would never have a call for 1500 RPM if the outside time were as high as 75. So those are just meaningless numbers. 1999 with stock idle valve and throttle body, and typically used frequency.
Last edited by DNMakinson; 07-09-2017 at 08:38 AM. Reason: Added third image
#53
Retired Mech Design Engr
iTrader: (3)
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,012
Total Cats: 859
My memory says that the commonly used value is 512Hz. I strongly suggest you change it to that. Why spend a bunch of time trying to get things to work properly when a fundamental parameter is incorrect? However, I will verify that value when I get home.
#54
The number is 511.
You might recall when I switched from the MSLabs MS3 Basic to the MSPNP Pro, I had a lot of issues stemming from trying to put the old tune in the new box. The folks at DIY strongly suggested starting fresh and leaving defaults alone. That's one I left alone. If I mess with it based on what I learn from exchanges on this topic, I will use 511Hz.
Thanks,
You might recall when I switched from the MSLabs MS3 Basic to the MSPNP Pro, I had a lot of issues stemming from trying to put the old tune in the new box. The folks at DIY strongly suggested starting fresh and leaving defaults alone. That's one I left alone. If I mess with it based on what I learn from exchanges on this topic, I will use 511Hz.
Thanks,
Last edited by poormxdad; 07-09-2017 at 11:46 AM.