I've installed and got the engine to run and idle pretty well but I still can not find how to set the expanded temps ranges for Tuner Studio. I have them set for Megatune but Tuner studio instructions are not working.

Here is the section in the manual that discusses the Expanded Temps


To use a MegaSquirt® controller with an air cooled engine, you will have to decide where the best place is for the coolant sensor: in the oil, or on the cylinder head (CHT). There are various arguments for and against using either CHT or oil temperature as the 'coolant' temperature input on air cooled motors. A lot depends on whether the motor is substantially oil cooled or not. Since the CTS input is used for warmup enrichment, you want something that responds fairly rapidly, so this is highly engine-dependent.

For high temperature applications (i.e. air cooled engines with a CHT), in MS-II you can set the #unset EXPANDED_CLT_TEMP by changing:

#unset EXPANDED_CLT_TEMP

to

# set EXPANDED_CLT_TEMP:

Then the upper temperature limit should be 600 degrees F. This is from the INI notes:

; FAHRENHEIT (Expanded/Normal):
; Low Limit: -40F/-40F
; High limit: 600F/300F
; Low danger: 150F/50F
; Low warning: 200F/150F
; High warning: 325F/200F
; High danger: 350F/220F

However, you have to calibrate the thermistor table(s) appropriately.

However, note that the tuning software limits the temperature range. The thinking is that if you are at an extreme it is probably a bad or missing sensor, so it goes to a default value. This isn't a big deal in TunerStudio though, you can change these limits in the ms2ReferenceTables.ini file. You can adjust these limits if EXPANDED_CLT_TEMP is set. Currently only the CLT sensor respects EXPANDED_CLT_TEMP, the IAT does not.

IAT min = -40, max=350 if outside that range it goes to 70 CLT min = -40, max=350 if outside that range it goes to 180 CLT with EXTENDED_CLT_TEMP min = -40, max=400 if outside that range it goes to 350 default

Here is the section of the ms2ReferenceTables.ini file that controls that:

; tableLimits (optional) = intentifier, min, max, defaultVal
; will set the default value if value is outside the min and max limits.
tableLimits = 001, -40, 350, 70
#if EXPANDED_CLT_TEMP
tableLimits = 000, -40, 400, 350
#else
tableLimits = 000, -40, 350, 180
#endif"

So the user can just edit the one line in ms2ReferenceTables.ini using notepad.exe or something similar to change it from:

tableLimits = 000, -40, 400, 350

to something like:

tableLimits = 000, -40, 600, 350

or similar, and it should work once the user re-burns the table.



In Megatune, you can use the configurator to set the

#unset EXPANDED_CLT_TEMP

to

# set EXPANDED_CLT_TEMP:

But in TunerStudio you have to edit the ini file and I've done both which only shows the expanded temps in Megatune and not in TunerStudio.

Need Help you guys?

I've done it in ms. What you will find is the actual readings will be garbage. I tried and tried, got it kinda close, but the sender is not linear enough to give you good temp readings. I have a industrial thermistor to play with that was cheap, but havnt messed with it since I blew up my motor.

Frank
I'm in the same boat. I will research and let you know if I find anything.

This will show you how to change the gauges:

http://www.tunerstudio.com/index.php/manua...ng-gauge-limits

I tried this and it worked for me.

I don't think this effects the software calculations, however...somehow we need to set expanded_clt_temp. I suspect this is why my idle changes based on temp...if I just come off the highway and sit at a stop light, my idle is elevated probably because my head temps are above 220 deg (boiling water) which triggers some emergency algorithm in MS.

That helps for the gauge. I've tried to e-mail for assistance and Tobin suggested I install MS2extra firmware but every time I try I get errors. The only firmware that loads correctly is the MS2-MicroSquirt latest.

Also, if you don't have your CHT sensor calibrated correctly or the expanded temp set, then the gauge will go back to the default reading of 180 because its out of limit and MS treats it like a bad gauge. I had it calibrated yesterday pretty good and getting to around 320 but not any higher (using MegaTune). This was in direct sun and idling on the driveway. If I reved the engine for a while the temps would drop so I knew I had it pretty damn close. Problem was, the AFR is still sketchy. I know I don't have any exhaust leaks but the controller acts like its out of limits as well and default to 22.3 most of the time. I can get the engine to run on a VE table but I can't do any autotune until I fix the AFR problem.

And once you get it to work, once the temp gets above 345 or so, megasquirt will go in to default of 180. It's the sensor, its just not a linear enough sender.

Not sure I understand your logic here. Regardless, I and ( I think ) frank are running automotive grade thermistors in the cht body and not the stock cht. The device is intended exactly for this purpose so linearity should not be an issue.

Frank, I have the thermistor characterized and calibrated. I get proper chts reported in my datalogs -- they match my cyl head temp sensor under the #3 plus pretty closely -- but i believe we still need to set that parameter somehow for the fuel injection to run as intended.

Got a part number for the replacement? I was using a stock cht. Once they got over 340 or so, megasquirt had issues with the large resistance change. I could get it from~50 deg f to 330 or so with good success and accuracy, but over that was all over the place.

McMark made it for me. Check out the thread in my sig for some details. I'm sure if you pm mark he'd hook you up

::hijack over::

I made the same type but I think Mine is a Higher Ohms resistance.

40F = 120K Ohms
68F = 40K Ohms
180 5K Ohms

Not hard to make just need a silcone coated thermistor and a drilled out stock CHT body.

I had a hard time finding a thermistor that would handle up to 400 deg. I did find a tc driver that will do the job, but it was more crap to add in to megasquirt. I'll pm mark once I get this thing going again.

If your already at 5k ohm at 180, once you double the temp think your going to run in to problems. Probably going to be in the m ohm range.

Not once the bias resistance is added in but I am going to go with the Ring style once that gets to me. I was reaching 320 yesterday and then when revving it would cool

The thermistor, like the stock cht, is ntc -- negative temperature coefficient. As temperature increases, resistance decreases.

Franks small chart above shows this relationship.

Not sure this will work. The ring style probe is a thermocouple -- it outputs a small voltage that's directly proportional to temp. What you have now is an ntc thermistor -- outputs a resistance that's inversely proportional to temp.

You may be able to configure the ms to accept the thermocouple input but more than likely you'll need a signal conditioner.

Good point I didn't think of that.

That's why we post here

anyone use the Stock CHT? I'd like to know the settings that you used for it?

I finally got this figured out but unfortunately, my AFR Gauge and controller do not work properly and I'm waiting on another in the mail. The even worse news is it won't arrive till tomorrow and rain is in the forecast. unbelievable.

Well this is what you have to do.

First download the zip file i attached

extract the folder to your TunerStudio Projects folder. Then open the readme.txt in that folder.
It will explain that you must double click the download-MS2-firmware.bat file and follow the instructions.

After which you can start TunerStudio and it will detect the correct ECU Firmware for MS2 Extra. If you have TunerStudio setup to load your last project you will get errors but don't worry because that will also transfer most of your settings over to the ECU (VE tables, AFR tables etc). You will however need to create a new project to have it correctly link with the ECU and then turn on the Expanded CLT Temp setting.

I like the setup of the MS2 Extra as it gives you the option for fuel only instead of having to turn off all the ignition and pickup stuff.

Be warned, it changes a lot of the buttons and adds a lot more options for things that you may never use but it also has some nice features. This should help stop any tuning issues with temp ranges some may have been having.