Base Lambda Changes having no effect... & Mg/Stroke ques.

[Trguy79]

I am doing my best to teach myself, but it seems there is either operator error, or VCM error. This is on a '08 Caliber SRT4 (GPEC)

Changes to the Base Lambda table are having no effect on AFRs or Commanded Equiv Rat. The only time I see changes is when in PE mode. I am looking to lean out cruise/light throttle and don't want to do it VIA VE tables and locking in open loop as this would inhibit fuel trims updating for environmental changes

Also, since I am unable to log KR, I figured the next best thing would be a math histogram in the scanner, but it is not populating (tried all of them). My last resort was to create a histogram to match the spark table (built in spark histogram is PRatio/RPM) and then compare in Excel to formulate LKR, but am having a horrible time figuring out the correct formula for calculating actual Mg/Stroke(also unloggable).
v1.7.hpt
nv ratios.xlsx

[Trguy79]

Also, the hell if I can figure out how NVRatio is calculated...

[06300CSRT8]

NV Ratio is Engine RPM divided by vehicle speed.

[06300CSRT8]

What you should do is create a math parameter for mg/stroke and then log it and add as your column axis label in your histograms. There isn't really a point to doing the math out in a grid in excel, for instance you have 12.6 g/s calculated out to 6600 rpms...you will NEVER have this scenario. Math should be as follows:

g/s x 60 x 1000 / rpm / 2

[Trguy79]

I agree Using RPM/MPH=NVRatio makes sense, however it does not result in a number that makes sense in any of the tables.

This formula results in
1st =168
2nd=99
3rd=67
4th=49
5th=39
6th=33

The table in Engine->Tq mng->Gen -> Manual Trans Tq limit uses values of 80-104-172-255. This doesn't correspond to any particular gear, and given the NVratio is fixed for any given gear, I would expect each gear to correspond at least loosely to one of the values.

Also in Engine->Airflow->Elect Throttle->Power % Request - The rows are 0-6.3-8.3-10-12.5-17-26-35-63. Again, doesn't seem to match up.

Thanks for the help!!! (BTW, had an 06 300 SRT8.... Man do I miss that thing!!!)

[Trguy79]

Is there a "how to" for creating math parameters? I cannot seem to log any air flow at all. Its a SD system, so there is no sensor that gives flow numbers, it's all calculated. Anytime I try to log any flow with a built in PID it just shows zero...

[Trguy79]

I updated my spreadsheet. Not sure where I came up with the formula I was using, but it was off by about 20%...

[06300CSRT8]

I agree Using RPM/MPH=NVRatio makes sense, however it does not result in a number that makes sense in any of the tables.

This formula results in
1st =168
2nd=99
3rd=67
4th=49
5th=39
6th=33

The table in Engine->Tq mng->Gen -> Manual Trans Tq limit uses values of 80-104-172-255. This doesn't correspond to any particular gear, and given the NVratio is fixed for any given gear, I would expect each gear to correspond at least loosely to one of the values.

Also in Engine->Airflow->Elect Throttle->Power % Request - The rows are 0-6.3-8.3-10-12.5-17-26-35-63. Again, doesn't seem to match up.

Thanks for the help!!! (BTW, had an 06 300 SRT8.... Man do I miss that thing!!!)

EDIT: let me read back up on my old SRT4 stuff, pretty confident while the NV Ratio doesn't directly correspond, you can simply consider each row gears 1-5 (appears HP Tuners is missing one).

[06300CSRT8]

Yea your GPEC read out is missing the various boost limits we have available for the NGC3s, you are missing the true torque by gear.

[Trguy79]

Wonder if it would be a good idea to write the stock file back in, and re read in case tables are available now that weren't on initial read. Not sure if it works that way or not.

Still unclear why my Base Lambda changes have no effect. Did just notice there is another lambda table in Engine-> General -> "Base Lambda correction".

I have tuning experience in MS and some other aftermarket systems, and good lord is the GPEC convoluted....!!!

Thanks again for your input...

[Trguy79]

Maybe it is laid out wrong. (x=mph y=NvRatio) = torque limit would be ideal...

Missing a lot of other stuff I would have thought would be there too..

I have looked and looked... I wish there was some sort of GPEC how to guide. Seems to be out there for everything else. Trying to grasp the hierarchical structure of the maps is ridiculous. Have pretty much come to the conclusion that 1/2 of the tables are not used and the other 1/2 don't do what youd expect or want them to...

[06300CSRT8]

Maybe it is laid out wrong. (x=mph y=NvRatio) = torque limit would be ideal...

Missing a lot of other stuff I would have thought would be there too..

No its right, in SCT its the same except there are about 6 more boost limit tables available, see the screen shot

SRT4 Boost Limits.JPG

[Trguy79]

Is that NGC3 or GPEC?

[B00STJUNKY]

Is that NGC3 or GPEC?

Going off of memory, that looks like the gear based torque limit table of the NSRT-4. So, non-CAN (which probably translates to SCI) NGC3.

[06300CSRT8]

Going off of memory, that looks like the gear based torque limit table of the NSRT-4. So, non-CAN (which probably translates to SCI) NGC3.

Bingo

[06300CSRT8]

Have you guys ever thought of just tapping the knock sensor wire, and running to the analog input on the HP Pro to log it? You could then export to excel and roughly estimate the knock based on the factors and thresholds, shouldn't be too hard.