H. AEM FIC Tuning for M62 Supercharger
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AEM FIC tuning
First let me say I am not a tuner! My knowledge on the subject is improving, but I am at best a novice. So, I do not recommend using anything posted here for tuning purposes. I am only posting this to make it obvious that tuning is best left to professionals.
Again, I am not a tuner. I gather data from other sources and try to apply it to what I am doing. The process below is my attempt at getting a base file for careful and methodical tuning of the M62.
We will take it very slow and only move into boost in small increments while logging the data and making adjustments realtime to the calibration file. The whole time we will be watching our gauges and listening for knock. Hopefully, we will be conservative enough in our approach to avoid engine damage.
I will not post my actual data since I am not sure how well it will work on our car much less another car. But I will post the process we followed to create and tune the AEM FIC calibration file.
One more time. I am not a tuner!
Calibration File Construction:
To construct an AEM FIC calibration file for start up of the M62 supercharger I followed this process:
First I copied the FIC calibration file I am now running on my M45.
I started making changes to the fuel, ignition and o2 maps. I made the AFR scale 0 on the bottom row and then from 13.7 (-1 psi) to 34.7 psia (20 psi) on the top row. I kept the rpm range across the top of each map at 0 to 7500 rpm.
I used the data rows from my M45 maps up to about 19.7 psia (5 psi) by copying and pasting the numbers into each map. I then extrapolated numbers for the rows above 5 psi to 20 psi by putting 100% in the top row and letting the program calculate the values between the rows. Now I had the original file.
Then I borrowed a FIC calibration file from a friend who runs a turbo up to about 12 psi with 440cc injectors to compare numbers at each boost level.
I relaized I would have to do something to get everything on the same base before comparing the fuel maps. To compare apples to apples, I changed the injector size from the 265cc injectors to 440cc injectors on my fuel map. Now I could more easily compare the fuel maps.
Actually, the fuel maps were very close from 0-5 psi. I increased the numbers using the Ctrl U function for the rows above 5 psi to 12 psi until they were close to the numbers in the borrowed file. Then again, I extrapolated numbers for the rows above 12 psi to 20 psi. I used 100% of the 440cc injectors in the top row and let the program calculate the values between the rows. My hope is that the fuel map will be fat for this level of boost.
Next I changed the injector size from 440cc injectors to 640cc injectors. I think this should be a good starting point for fueling.
For the ignition map I followed the same process basic process. I started by pulling 1 degree of timing for each psi of boost. I did feather the edges of each row toward the power band instead of the using the same number all the way across the map. When I was finished, my ignition map was more conservative (pulling a little more timing) compared to the borrowed ignition map.
I did not change my M45 o2 map except to change the scales to match the fuel and ignition map scales and to fill all the cells from 0 psi up with .19 to force the OEM ECU into open loop when in boost.
For settings I used the same ones from the M45 FIC calibration file and made the changes needed to match the new supercharger as follows:
I used the Flow Force's website injector data Dead Times by Voltage and Fuel Pressure chart for the injector response time at 13V. We will be measuring our fuel pressure and may have to make adjustments to this number as we get acutal data from our testing.
Then I changed the Switched 12v to come on at 20.0 PSIA and go off at 19.7 PSIA. We will start tuning only from 0 psi to 5 psi at first. Once that is working well we will try to move to the next 5 psi level and so on. To accomplish this we will try to be careful with the accellerator. That is also why I made the warning system detailed below.
I had to change the table for the AEM wideband to be set for the digital meter values. The M45 has an analog AEM UEGO 30-5130 gauge installed. It uses different numbers for these settings. I used the AEM UEGO 30-4100 table data for the auxilary gauge settings.
Now I think we have the file we need to start running in boost. We will start slowly with small incremental increases in boost until it is clear we are not having detonation issues and the AFRs are good.
We still need to load the start up calibration file to the FIC before we can start the engine again.
I have already verified the FIC has the correct hex file loaded. That is the file that controls the FIC calculations. It is very important that the correct file is used, or bad things can happen. This Miata requires the z110.hex file to operate properly. Ken Hill helped us to figure that out when we were stumped with a bad hesitation when tuning the M45. Thanks, Ken!
We will make logs with the FIC software we loaded onto my laptop. Then we view the logs in the AEMlog program that can display graphs of the data logs. Both these files are available free online on the AEM website: aemelectronics.com
Warning Buzzer and Light:
We may try to limit boost mechanically if we cannot control it well enough with the accellerator. We will set a warning buzzer and light that will sound when boost is over the value we are trying to tune to. This is how we made a warning system.
I found that the AEM FIC has a feature will allow us to monitor boost and use the 12V output to sound an alarm at a level we can pre-set. I think that will be useful during tuning to help monitor boost while we monitor other things, especially knock and AFRs.
I remembered a buzzer that was on my bass boat. It was there to warn you if the automatic oiler ran out of oil. I prefer to mix my boat fuel manually, so I had disconnected the oiler years ago. I found the buzzer under the dash.
I removed it, tested it, added a small light and inserted it into a large piece of pipe foam. Then I found the Switched 12V feed from the FIC and connected it and a ground lead to the buzzer. I included some quick disconnects in the leads so we can remove it if it becomes a distraction.
The small white light will come on and the buzzer will sound when boost reaches the level we set. I hope it helps us tune in small steps.
We may be running tomorrow!
It took us almost the entire weekend to get the engine running where tuning could begin. For details on that see: I. Engine Start with M62 Supercharger
After all those issues were sorted, we were finally able to take the car out and apply a little boost later in the day on 08/07/2016. We started with trying to limit boost to 5 psi. The alarm system was a big help with that.
We made several logs running from 2000 rpm up to about 6500 rpm while trying to hold the boost at 5 psi. A few times we bumped the warning system and it worked great!
Once we made the logs, we would retreat to the house and look them over and try to make improvements. We both wanted to try some different things so Matt made adjustments to a fuel map and I made my own adjustments to a fuel map. When we made logs of both fuel maps, it turned out that Matt had the better fuel map.
The engine ran fine in boost. But we were still having issues when running out of boost. The engine hesitates when not in boost, sometimes stumbles several times in a row, the idle dips too low most of the time and the engine dies on occasion. We need to make some changes to the lower end of the fuel map and probably change the scale along the boost axis. We are not yet sure, but will seek guideance and make some changes to see if we can fix that first.
Maybe I can find some things to try during the week while Matt has to work. We will see!
Subpages (6):A. BRP M62 Hotside Kit B. Supercharger Parts List C. Supercharger Engine Build D. BRP Intercooler Kit Install E. Supercharger Gauge Set Intall F. Supercharger New Engine Start Up G. BRP M62 Supercharger Install I. Engine Start with M62 Supercharger