MS2Extra 2.1.0 Table switching Mod?

[gforce]

Would it be possible to add CLT as a switch in order to use table switching as a means to have a separate table for warmup idle? I find that my car uses the same part of the map for warmup as it does for off idle driving once up to operating temperature so if I adjust the VE to get the mixture correct during warmup I am far too lean in this area once I approach operating temp and this has some undesirable effects on drivability. I have zeroed my ASE and have reduced WUE considerably (75-80%) to try and get a leaner warmup however I am still in the 11.5-12.0 AFR area during warmup eventually tapering to a decent stoich idle once I reach operating temp.

[Hardwyre]

You could use a relay connected to one of the programmable outputs set to switch on a coolant of your choice. Then have the switch terminals of the relay connected to the table switching pins. But that all seems far more troublesome than you need it be.

Can you post a datalog of your warmup period? I'm curious just how high you're having the engine rev as well as a couple other things.

[gforce]

I forgot to mention that I have a fairly aggressive camshaft as well as ITB's on a BMW M20.

I think its simply because that part of my fuel map is dialed in for normal off idle driving once warm (80-85kpa at 1200rpm) with no stumbles or lean conditions. Once warm the KPA at idle is around 58-60. Ive even tried setting my WUE down around 80% to get a leaner cold idle but its still not enough to overcome the warm fuel map plus has some effect on my cold start.

Idle at operating temp is 1050, 58KPA but when at 40F the ICV goes full open (hence the 80ish KPA when cold) to overcome the rich mixture and try and maintain my target cold RPM which I have set to 1250. An idle VE map that switches with a set temp will be ideal in my situation. Apart from the rich cold idle the engine runs perfectly, it even runs good during warmup...just rich, and with no cat there is a strong fuel smell during the warmup period.

I have enabled EGO correction for down around 40F and upped the controller authority to bring the cold mixture closer to the AFR target as a work-around for now.

[Hardwyre]

Okay, I get it. So you're familiar with the hardware mods to the board itself you have to make correct?

My though would be to use a small SWITCHING NPN transistor (not an amplifying transistor), something like a 3904 should just fine in the area of the active circuits where it says 'switch'.

http://www.msextra.com/doc/ms2extra/MS2 ... ableswitch


This is what is running in my head right now:


This SHOULD let you assign a programmable output (http://www.msextra.com/doc/ms2extra/MS2 ... ms2options) that gives you a +12V (I believe the IAC1A and IAC2A are +12v) to be on until your coolant reaches a certain temperature. While this output port is 'on', you should be able to set it up to run VE Table 3, then, when you're coolant exceeds a temperature of your choice, it turns the port off, thus breaking the circuit, switches off the VE Table Switching switch, and reverts back to VE Table 1.

If you're feeling a little more daring, you could just us an LM7805 +5 volt regulator (http://www.radioshack.com/product/index ... Id=2062599) with the +12 input coming from the programmable port, the ground leg to ground, and the +5 output to the VE Table Switch port. The daring part comes from the fact that if the voltage regulator ever died, it might spike some bad news into your CPU.

Now, if one of the programmable outputs was +5 volts from the get go, maybe one of the LEDs, you might get away just wiring it in, but again, probably not the best idea.

These are all just speculations, I would encourage you to message one of the experts if no one else chimes in on this thread.

[jsmcortina]

There's no need for that second circuit. The CPU will provide enough current to switch the transistor as it is - check the existing LED circuits in the schematic.

James

[gforce]

Thanks for the replies guys.

I believe I have used most if not all of my programmable outputs for spark outputs (A B C) Fan control, Tacho, and 4 wire IAC Stepper. I will have to have a look and refresh my memory as I havent had the case out of the car and open for some time, it doesnt sound too difficult though if I can use one of the programmable outputs, if available, as a switched input.

I was hoping that there may be an easy way to implement this CLT based switching function into the firmware and possibly also take advantage of other constants such as TPS position and such so the warmup map will switch to the primary map for cold driving. Im exploring what options are available.

[gforce]

After looking through the documentation you provided links to I think I have somewhat of a grasp on this circuit.

The only programmable output I have available is JS11 (PA0), will this output (12v?) be capable of switching the circuit as pictured in your "Active High Input" drawing without the use of the 2N3904?

I am far from being an electronics expert so Im trying to gather as much information as possible and create a simple step by step process/drawing before I attempt to implement this mod.

[racingmini_mtl]

If you want to use JS11 to activate table switching then you don't need the circuit shown above. You can simply connect JS11 to pin 15 and do the MS2 card modification to make PE1 available on pin 15. A CPU output pin can be connected to a CPU input pin. In this case there will be a 1K resistor between the 2 pins which is a sufficient protection for any transition the pins will go through when booting up or when loading code.

Jean

[gforce]

Jean,

OK, I think Im getting closer to understanding this now...

Please correct me if Im out to lunch here, so -

Remove R1, jump JS11 (pin18) to bottom of R1 (pin15) then jump pin15 to the unused leg on the C64 chip?

If this is the case it sounds simple enough, apart from maybe the microscopic soldering to the unused chip leg.

Guy

[racingmini_mtl]

Guy,

That's correct. And you're also correct that the soldering on the CPU pin is something to be very careful about.

Jean

[gforce]

Can the CPU pin be free of the daughter board or does this soldered connection to the board need to be maintained?

[jsmcortina]

Leave it soldered to the board, use the thinnest wire you can get and proceed with great caution. If you aren't 100% with soldering please entrust it to someone else.

James

[gforce]

I may need to have someone do this for me...soldering to the chip is very intricate indeed.

[jsmcortina]

Is that your CPU? I presume not as the photo shows a beta card that was not generally released. There's a photo of the wiring in the manual already.

http://www.msextra.com/doc/ms2extra/MS2 ... ableswitch

James

[gforce]

No, thats not my chip...Its a picture I grabbed from the web to use as an example, I added the yellow lines to illustrate the connections I need specifically.

[Hardwyre]

An individual wire from an old hard drive ribbon cable is what I used for mine.