For the first time yesterday I had my LM-1 working in the Z06 and below 3 graphs that I have extract from the many sessions I run during the afternoon.
This unit is easy to use and when the calibration was done, really accurate, it was easy to repeat the same #, and the average at iddle is pretty close of the 14.7 of stoich.
Looking closely to those info, seems that there is a lot left in the tuning and that my PCM is working a lot:

-

-

-

Christian

 

Christian, is this stretched at all, or is totally condensed? Looks really ragged. The 2nd one has the spike for the gear change DFCO is working. Yeah I'd say there is a lot left in her. If your NA I would dial the AFR on the street to read 13.1:1, slightly fatter 12.5 or so on a non-loading Dyno. But seeing yours drops down from 12.2 (too fat already) to 11 is crazy, unless I am missing the SC or TT in your sig and numbers!

For comparison at idle I am at 14.4-14.9 with a slight pitch and yaw from the cams idle, at cruise I am at 14.5-15.1:1 a little wave if you will as the rpms are low enough to still let the cam rise and fall slightly. At WOT NA Tune 12.9 up to 4800, then trims out to 13.3 until shifts 6950rpms, peak tq rich, peak hp leaner. Nitrous Tune is 11.7 at 3500 (stall flash rpm) trimming to 12.3 at pk tq, then trimming slightly to 12.7 shifts. those are logged from real world no dyno. If you dont mind can you email the log?

Charlie

cat3n4@gmail.com

 

I just started logging on my LM1 also. I have the same sine wave effect of up and down on some runs, and more consistant on others. I don't really understand that.
My best run had smaller waves, pretty consistant at 14.2 at mid throttal, and right on 12.7 at WOT from 3000 to 5000, then it started to richen up to 12.3 at 6500.
I am thinking of tuning PE or VE to get a flat 12.7 at WOT. It looks like you are in the same boat, how do you get a consistant WOT.

 

Hello CAT3
the first graph is approximately of 1mn20sc, and I was with the cruis control on, no influence on the throttle, I didn't use any smoothing in the translation of the data (it's more accurate from my point of view) and you can see some jumps from 13.5to 15.4 in a very short time...

the second graph is approximately 10sc smashing the throttle in 2nd gear to 7000rpm and upshifting to 3rd to 7000rpm also, changing gear seems to be around 0.6sc with a normal reaction of leaning of throttle but jumping on the pedal is already too rich, and the high revs are with a lot of unburned fuel...

the 3rd graph is approximately 18sc and it is going WOT in 4th gear going up on a long ramp from 3500rpm to 6400~rpm, beginning at 12.2 and hending at 11.05 of AFR....

My Z06 is NA and for sure a good tune is going to increase the power, those AFR# wants to be in the right place, the LM-1 is a tool very helpful.
I have sent you my logs from yesterday !!
Christian

 

Ah ha, the Cruise will effect throttle, if you log you will see that the Cruise Control will open and close the throttle blade, however slight, to maintain as close to set speed as possible! The sine effect is somewhat normal, as each condition (weather, load, rpm, etc) changes, but the concern is to have adjustments made in the PE for WOT, DO NOT USE VE for that. Most VE tuning is for a cam to idle smoother, until the VE is calibrated/dialed in. I adjust the PE Table, so the left half (from Peak TQ is rich (around 1.200 or so, depending on NA or Nitrous and each combo/tune is different. The slowly begin leaning each cell from there on to the right out, next cell from PK TQ would be like 1.190, then 1.184 and so on until it matches up with desired AFR at peak HP, for me 1.104 IIRC) rich then the right leaner.

As stated in pm, and for anyone else, I am not sure what tuners in the mainland do, but I try to have as much log time as possible to tune using the prescribed steps, Basics (idle rpm, trans, fans etc) then PE (WOT Fueling) Timing (No KR and timing curve follows the fuel curve, lower on left more advance on right), VE, MAF, fine tune Idle and go back and check everything. I probably spend more time tuning other peoples cars then my own, logging vs tuning time is like 10:1. I am under the impression most tuning appointments are for PE, Timing for WOT, but the that does **** for the car like Miami 993....who has H/C/Intake (meaning CAI) and other airflow modifiers that throw the VE and MAF out of whack. Correct me if I am wrong, but just what I keep reading. Why? Because as mentioned, it takes a lot of logging time, lots of it, to really dial a tune in. I have consolidated about 1:39... of logging time and I am no where near ready to do the VE as when its broken down there is only a few samples per rpm/per airflow/per temp (IAT vs ETC). Need lots more.

Charlie

 

Well, after paying for 3 tunes over a couple of years, yes, you are correct in that no one does the part throttle tuning right. Too much time as you said! One guy in Columbus OH at least took the time to try and get part throttle ( 2 hours ).

A friend bought HPTuners for us recently as we figured no one can log the car like we will/do or cares as much. May as well do it yourself if you REALLY want it to be perfect. Pay someone to tune thr WOT on the dyno after you get the VE table and idling in-line. Or, if you can afford it get the LM-1 or equivelant and do that part yourself too ( just pay the standard $100 an hour for the dyno time ).

 

Id be interested to see the graphs on a dyno constant no varying load throttle changes along with steady throttle. I still think you would see a sinusoidal effect but not as exagerated

 

I totally agree with you Charlie , I can't imagine no variation in the throttle blade to maintain a constant speed, just because all the parts involved in the transition of the engine power to the wheels are permanantly changing of temperature or moving around frequency that can create tension etc...
But a variation of ~2 points of AFR every second at constant speed in straight line at see level, totaly flat is for me something that the GM designers have not imagined, I can't believe that.
I worked some years ago on engine dyno, not as an eengineer but as a mechanic(it was a good time), and I remind clearly that the measurements recorded about AFR were pretty constant with a very slight sinusoidal, but this was at the begining of the electronic in the cars, maybe it's different today, just want to see if those graphs can feel less bumpy.
It seems that tuning is a long road, and I am sure that some of you have already spent enough time in tuning your PCM to show now data that are more decent that the one I have in my Z06.
I will have my car retune soon, I will update my new AFR graphs, and thank you all one more time to share your experience, it builds mine.
Christian

 

I am not exactly sure why the wave is there, other than difference in lambda, but I had dyno'd (non loading)once with my LM-1 in and it was just as nice looking as the street (real load). There is a slight wave, not varying more than .3 from desired AFR and it was slow sweeping, I contribute to fuel pulsing or something.

 

I want to post a LM1 file for comparison. How did you save the LM1 file in a format that you can post on this web site. ??

 

Hello racecar
email me your data, I will host that for you :
cboudon@bellsouth.net
Christian

 

Hi,

The first log is obviously at cruise condition where the ECU runs in closed loop using the narrowband (stock) O2 sensor. Any ECU made since about 1977 with NBO2 sensors works like that. The NBO2 sensor switches at about 14.7 AFR. The ECU richens up the mix when the sensor output is below 0.45V and leans out when it's above. IT DOES NOT READ THE ACTUAL VOLTAGE. It just compares it to 0.45V and oscillates back and forth around 0.45V sensor output (14.7 AFR). That's what's called cross-counts. When NBO2 sensors age, they react slower and the oscillations become slower and larger because the ECU richens up and richens up until the sensor finally reacts. Same on the lean-out phase. In the provided log it looks like the NBO2 sensor is on it's way out. That's why the oscillations cover 2 AFR max. Depending on the ECU and sensor they are typically less than +- 0.6-0.7 AFR.

Regards,
Klaus

 

This scan looks a lot smoother. It drops to 12.7 at a WOT, that was 3000-6500rpm. It gets rich at higher rpm. Drops to about 12.3.

 

Why dont u guys have AF in Y and RPM in X? I mean putting AF in Y and sec in X isnt really accurate. Would the LM1 allow to choose the layout of the graph?

 

There is a way to hook up RPM, but it is still on the same X time scale for the playback mode. I'm trying to find the tach signal wire to capture rpm. Any idea where that is on a 99 C5??

 

Easy to do in LogWorks. Just select the run, then open an XY plot window. Select RPM as X and AFR as Y.

 

Thats good to know.... Im getting the LC1 with FlashScan so I wasnt worried about logging RPM VS AFR, but i was just suprised no one did it when logging their AFR.