Step Testing

[4pointslow]

This started out to be about step testing but has and will become a comparison of Different SCT devices and other things.

Step Testing is a method of tuning the A/F mixture on a vehicle at lower RPM's.
It is often done at different rpm's like 1,000 / 1,500 / 2,000 / 2,500 up to about 4,000.
Some target MAF readings instead of rpm since that is what is adjusted to correct the A/F anyway.
The picture below is a stock MAF transfer function for my Explorer.
The green highlighted box is the amount of airflow the pcm will think it is getting when it see's the voltage
in the box to the right. Just a note that computers dont understand analog voltages so they are converted to
digital counts which is the box to the left of the green highlighted one.
The MAF counts is one of the things we datalog during tuning. If you look at the counts to the left of the green box
you will see it is 245 counts. The PCM will add the same amount of fuel from 245 to 285 with this transfer function.
At 286 it would add more fuel based on the next count.
So targeting in between 245 and 285 at around 265 would be most accurate when trying to get readings.
You would watch the MAF counts while pressing on the gas pedal and trying to hold it steady at 265.
You would also datalog STFT (some use wideband instead). At lower rpm's STFT is an adjustment to A/F.
You can take the high point and low point from STFT during a steady reading at a certain maf count,
and add them together then divide by two to get the average.
You then take 1 and divide it by the STFT average to get your correction factor. (I think it is called the reciprocal of the average STFT)
You will highlight the box in the MAF transfer function like I did (turns green) and right click it and multiply it by
the correction factor.

 

[4pointslow]

Datalog

This is a datalog of my 4 door explorer that is in good running condition. It is noted that you would need fully
functional O2 sensors, and a vehicle with no other running problems besides the A/F being off due to aftermarket add ons.
You can not tune a vehicle properly that has failing components, misfires, exhaust leaks etc.
In this picture you can see the MAF counts and STFT for one bank. That is all you will need. I made this recording with my
first SCT "X3". The serial number starts with an X3 and it only holds 3 tunes at a time. I like it for datalogging because I
get good data and you can get it started datalogging pretty quickly. You can only use Live Link 6.5 to set up the sensors you want to record.
Live Link Gen2 will not work for setting up this device.
I started this thread to show the differences in datalogging between a few devices I own
and to show a problem I have with my injectors being too big.
Please note that you can see the nice cross counting of the STFT. In the Live Link program you would zoom in to get the high and low points of the STFT.

 

[4pointslow]

"Enhanced" X3

This is a picture of the MAF counts and STFT datalogged on my 4 door explorer with an enhanced X3. The serial starts with XP (instead of X3)
The enhanced version holds 10 tunes.
That is a function I would really like to take advantage of. I could have ten tunes already written and loaded up on the X3.
It would make my test and tune nights at the racetrack a little more productive.
Another thing is that you can use Live Link 6.5 or Live Link Gen2 to set up the sensors that you will record.
I made the first datalog with Live Link 6.5, the second two with Live Link Gen2 (first with rapid packet on and third with it off).

One of the sad things is how long it takes to start a datlog.
You have to click way more buttons and then it tells you to wait for what seems like an eternity before it actually
starts recording. But even more sadder (lol at bad english) is the datalog itself from this enhanced X3. See below in the
picture how the STFT readings dont even look like they are crosscounting correctly. This is just bad data, unusable for tuning.
It could be that the X3 is faulty. I will try to datalog another vehicle at work with this X3, that I know works with another enhanced X3.

 

[4pointslow]

X4 datalog

Here is a picture of my first good datalog with an X4.
I have had it for a while but it was useless for datalogging with my old trucks until some bugs were worked out and a newer firmware
was available from SCT.
It can not be set up for what sensors you want to datalog with Live Link 6.5, only Live link Gen2. It holds 10 tunes.
The device also has a colour screen, pretty nice looking. It is different to use so there is a learning curve. I also dont like the mini or micro
usb port on the bottom. It looks like it will not last that long.
The older X3's had a much larger USB port that held up for the 5 or 6 years I have had it. It still works too.
The other frustrating thing is setting up the X4 datalogging with Live Link Gen2. There are three types of sensor selections(for lack of better words)
There are PID's, OBD's, and DMR's.
So you try to select STFT but there are three of them. The difference is supposed to be the speed at which the information can be updated in the
datalog, or resolution of the recording. The problem is most of them do not work. They have very erratic readings.
In one failed attempt my 4 door was at 220,000 rpm's. Again bad data that you can not tune off of.
There was a recent update in august that allowed me to get the good datalog below. You can see that there are only 6 things in the datalog.
I have to try to find all the things that I used to datalog and add them to the X4 configuration. It will be hard since they are named differently sometimes
and sometimes they just dont work. Maybe after more updates....

 

[4pointslow]

My 2 door Explorer datalog

Here is a picture of my supercharged truck's datalog.
This is using my oldest X3 that never lets me down.
You can see by looking at the STFT that the pcm can not control the A/F very well.
The STFT crosscounts are very abnormal looking. This led to the O2 sensor monitors not running.
It is not as bad at higher rpm's (highest step)
I had to install my older 30 lb injectors to get them to run. Now I am back on the 60lb Seimens Deka ones.
I am thinking it is probaly just a little too much injector for the truck's old pcm.
After all the stock ones were like 19 lbs or something.
Maybe going to 50 lb ones and raising the fuel pressure to compensate for them being smaller will work.

 

[4pointslow]

OBD monitors

Here is the OBD monitor test not passing(with 60lb inj) and then passing with the smaller injectors.

 

[4pointslow]

Complete step test

Here is what a completed step test may look like.
I did this one back in 2013 and by the looks of it, I had the 60lb injectors in it.
You can see where the STFT looked erratic on the first two steps.
Looks like crappy data but it is really the PCM struggling to control fuel adjustments.
I am convinced that the 60lb Siemens Deka injectors are too much for my PCM.
I would have to zoom into the other steps using the Live Link Program to see how they looked.
I will also point out that if you have changed a lot of things on your vehicle that you could start by doing the step test
in Park or Neutral to get things close and so it will at least Idle. Afterwards you would do it under light loads like driving on a dyno or down the street.
The street would be most accurate but good luck finding a stretch of road where you could hold it steady for 10-15 seconds for each step.

 

[2000StreetRod]

function lookup interpolation

. . . The green highlighted box is the amount of airflow the pcm will think it is getting when it see's the voltage
in the box to the right. Just a note that computers dont understand analog voltages so they are converted to
digital counts which is the box to the left of the green highlighted one.
The MAF counts is one of the things we datalog during tuning. If you look at the counts to the left of the green box
you will see it is 245 counts. The PCM will add the same amount of fuel from 245 to 285 with this transfer function.
At 286 it would add more fuel based on the next count.
So targeting in between 245 and 285 at around 265 would be most accurate when trying to get readings. . .

According to the CRAI8 source code the analog voltage from the MAF sensor is converted to A/D counts for processing by the PCM. There is a Function Lookup Interpolation called "fox" that interpolates the MAF transfer function table A/D counts entries to determine the associated lbm/tic. I think the interpolated value is used to calculate load so it should not be necessary to pick a count midway between two entries in the MAF transfer function table.

 

[4pointslow]

Midway

The midway position is so that you don't cross into another count when you are tuning that one. If that makes sense. It is just for tuning the MAF transfer function.
A very qualified Lightning tuner named Eric keyed me to the fact that you should target the midway point. Greg Banishes DVD also shows him targeting the midway point but it is very subtle. If it were not for Eric I may not have picked up on it.

 

[4pointslow]

datalog

2000streetrod,
I would still love to see if your vehicle is running the rapid response O2 test or not with those 60lb injectors.
Maybe I can look into what the PID's are actually named in Gen2.
What does your X3's serial number start with? an XP or X3?

I am thinking around 50 lb injectors might work if I raise fuel pressure to compensate.

 

[2000StreetRod]

XP X3 Power Flash

Unfortunately, I have the XP X3 Power Flash with the poor resolution plots using LiveLink Gen-II. I agree that having 10 tunes available is desirable and the memory is large enough to record twenty or more pids for longer than 30 minutes. But the plots are pretty ragged. The one below is about as good as mine gets.

Vehicle speed (blue line) = 28.5 mph
I wondered if the poor resolution was due to the X3 or LiveLink but after seeing your superior resolution with the older X3 and LiveLink I now know the newer XP X3 is the source of the problem. I haven't tried recording just a few pids to see if that improves the resolution because I need most of what I log.

If I ever get my Sport back together I'll be glad to help with your rapid response O2 testing. If my test doesn't run or runs and doesn't pass is a pending DTC set?

 

[4pointslow]

Sport

Uh Oh, what are you doing to it now?

 

[2000StreetRod]

front end removed

Much of the front end is still removed while I rework things to lower my IATs: Decreasing IAT on my Supercharged SOHC V6
It's taking way too long to complete my cold air intake. Today I finally finished roughing out the three pieces that will comprise the upper section of the air filter enclosure. Next I have to connect them with epoxy and fiberglass.

 

[4pointslow]

Datalogging with Just X3/4 vs Passthrough with laptop

The posts above were of datalogs using just the X3 or X4 to record them.
The first picture below is just using the older X3 (serial starting with X3), the second picture is datalogging with my older X3 (serial starting with X3) using pass-through and a laptop.
There seems to be no difference in the resolution of the recording.
Note that My 4 door needs a tune up and may also have a vacuum leak or slight exhaust leak, so Idle looks a little erratic. I will get to that tune up sometime this week.

 

[4pointslow]

X3P (newer X3 serial starting with XP) comparison

The first picture here is with the newer X3 using passthrough and a laptop,the data looks usable.
The second is with only the X3, you can see how bad it is. Not usable data.

 

[4pointslow]

X4 comparison

The first picture here is using passthrough and a laptop.
The second is using just the X4.
Not much difference here. The glitch on the middle step is just me changing the gas pedal position a little sooner.

I might start using the X4 if SCT gets a vehicle acceleration rate PID to work with it in the next update.
Also note that I just used Livelink 6.5 to open the datalog for viewing purposes. You have to use LiveLink Gen2 to set up the PIDs or use passthrough.
The X4 is not compatible with Livelink 6.5 but you can open the files recorded with an X4 with 6.5 or Gen2.
You can also open X3 datalogs with 6.5 or Gen2

 

[4pointslow]

No DTC

If I ever get my Sport back together I'll be glad to help with your rapid response O2 testing. If my test doesn't run or runs and doesn't pass is a pending DTC set?

I have never had a DTC for fuel control with my supercharged Explorer, and I would expect to, seeing how it looks at lower rpm's and the fact that it can not run the monitor test.

 

[4pointslow]

LiveLink GenII

There was an update to LiveLink GenII released yesterday.
After installation there was an error opening the program. I was lucky to find the solution posted at the same time as the update to LiveLink.

For some reason you have to go to the C: drive, the go to program files and SCT. Then LiveLink GenII folder and right click LiveLink.exe and go to Properties - compatibility tab. At the bottom just under privilege level there is a box called run this program as an Administrator. Put a check in the box by clicking it.
I should state that I am using Windows 7, and will be testing it out on windows XP in my truck. Other systems may have slightly different ways of "running as administrator".

I have installed it and will be checking it out today. Just so happens that ATCO Raceway is open tonight for test and tune.

 

[4pointslow]

LiveLink Gen2 and X4

I was able to use the X4 and LiveLink Gen2 for all the "things" I normally want to record. The latest update to LiveLink Gen2 seems to have gotten most, if not all the possible things to record available for my older vehicle. Up to now it seemed to work only for the newer vehicles and even then it had problems.

I added vehicle acceleration rate to the things I want to record to see if it will help with trans shift point tuning at the track. It did not previously work with LiveLink Gen2 and the X4, but with this latest update it works fine.

I only have one more concern at the moment that is really eating at me and making me want to stay with the older X3. It is when you set up the X4 to record data by itself with no pass-through. It works fine except for the analog input from my wideband O2.

I have entered the analog equation to display A/F in LiveLink Gen2 and the X4 but it wont stay there when recording with the X4 by itself. In other words you can see it on the X4's display screen as A/F(not useful), but not in the saved or uploaded datalog on the laptop/PC. The datalog will show the voltage instead of the A/F ratio. I don't want to convert it in my head or on paper when I look at it in the datalogs. I just want to see it in A/F at a glance, I don't often have time to study the data to decipher it. If an adjustment is needed, I have to do it fast so I don't miss the next run at the track.

Now when recording using the pass-through method the datalog shows the A/F ratio. Even when the datalog is saved it is still there. So the problem is only when recording with just the X4, not using pass-through. Using pass-through has other problems like glitches from data hiccups (for loss of better words) or even worse the X4 (or other devices) will loose communications with the vehicle or PC and render the datalog useless. That is why I have always used the older X3 by itself when recording, I could record a 40-60 minute ride to work by simply clicking a few buttons on the X3, and there would be no glitches and no loss of communications the whole time.

I have tried the X4 in pass-through and it already gave me a communication problem that rendered the data useless. I had to unplug the X4 from the PC and the vehicle, then plug them back in again to get it to start working again. If I can just get the X4 to keep the A/F analog settings to stay when recording by itself I will be able to use this device the way I need to.

I plan on doing some more testing with it today, I need to go over some IAC settings and soften up some low throttle shift points in my tunes(the 4.88 gears make them harder). It will be a good test to see if the things I need to datalog for them will work in LiveLink Gen2 and the X4.

 

[4pointslow]

USB on X3 and X4

The USB connector on the X3 was a larger and more durable connection. It is a "USB type B female". It proved to hold up pretty well for most users that didn't have to unplug and plug their X3's in due to communications issues on a regular basis. The professional tuners have experienced some failures of that connection since they were using them more often than others.

The USB connection on the X4 is a "Female Micro USB". (Micro not Mini)
This connector was noticed by the professional tuners right away and they were concerned that it would fail prematurely, or at least quicker than the older design. With having to plug and unplug it frequently due to communication issue's, you can see their point.

I have USB cables run in my vehicle from the onboard PC in the back of the truck, to the center console where I have an OBD connector and my X3 or X4 device when recording. I ran one cable with a female usb for the dongle or USB drive, and another with a Male Type B USB for the X3.

When I got the X4 I saw the different connections and ended up getting some adaptors to make it work. My plan is to leave the Micro usb adaptor connected to the X4 all the time and just unplug the Male/Female Type B connections at the other end of the adaptors.