Anyone else running MegaSquirt?

[DE80q]

So I had a system built specificaly for my MC1 20vt swap. Eric preloaded it with a base tune to get me started, but the tuning will be up to me. I have little to no experience tuning, and was wondering who else has experience tuning with tuner studio. I know Shawn(vt10vt) is running his MC1 on MS1, but he is the only one i know for sure that is running it.

For referance sake, my ECU is a MS2 cpu with a V3.0 board. This was set up to run fuel and ignition. In its current setup, I will be using an NG dizzy to trigger the system. I do have the divider board to use the factory VR sensors on the flywheel as the referance, but that will be used later.

Any one else here on the pad running megasquirt that would be willing to field questions?

[loxxrider]

I used to use mega-squirt software when VEMS was using it as it's interface. I also have tuned my bud's E30 on it and have MS3 for my 635csi (not completed yet). So I am pretty familiar with TunerStudio, just not really for an Audi setup in particular. It is pretty simple and user friendly so I wouldn't expect much trouble.

[bradyzq]

I built an MS1 for my 4kq, still on its JT. I used the MS'n'S code so that I could control spark too. I used only a 5 window distributor (the stock 4kq one, even though it has mechanical advance in it) for timing control. It works fine for a bomb-proof normally aspirated JT 20v, but I wouldn't suggest using it for you on your turbo 20v.

Use the 135 flywheel teeth, reference pin, and cam sensor (1 window dizzy Hall sender) setup that Eric has built up for you. Using only a 5 window dizzy is a big step back from stock.

[SEStone]

There is a ton of timing jitter when using the distributor. Like, if you get the car running, noticed that under every condition the RPM is bouncing around +-50rpm. As the others said, use the flywheel trigger and you'll have a much higher quality, more accurate, less-likely-to-destroy-stuff signal telling the ECU what the crank angle is.

Sam

[DE80q]

Thanks for the responces guys, sorry to take so long to get back to this. For whatever reason I am not getting notified of posts anymore.

Anyway... I do own the divider board and chip for it, but it has not been built yet, not to mention I really am not even sure how to hook it up. I do however, have a PM out to Eric on what needs to be done. The more I have been thinking about it, I think you guys are right, and I should just build it all right the first time, and make it run well. The original plan was to just get it running and driving for winter, and do the upgrades a little later. Well winter is well apon us, and it is still sitting. Maybe its better this way.

[vt10vt]

At this point, since I'm doing it anyway and I have to build/test one might as well do two and save you rewiring the whole car a second time. I am admittedly a little worried about all the issues other people (besides Eric) have had with the setup, but it seems pretty ironed out now and with my car running on the distributor I can just hook up my VRs and scope the signal without the car even depending on it which should make it easier to confirm a good trigger.

[bradyzq]

If you really don't want to deal with the 45-1 divider board stuff, you can always use the 60-2 trigger wheel that's integral with the rear crank seal. I think it's from a VW Polo 1.4T or something. Details can be found, and I think Marc might even have them in stock.

[vt10vt]

If you really don't want to deal with the 45-1 divider board stuff, you can always use the 60-2 trigger wheel that's integral with the rear crank seal. I think it's from a VW Polo 1.4T or something. Details can be found, and I think Marc might even have them in stock.

I looked into those, it is a great option but extremely pricy compared to the ~$35 for the translator stuff, and it should be fun to mess with and get working, I just didn't want to deal with trying to get a first start on it. With the car running and a scope on it, it should be much easier to work with than trying to figure it out with cranking

[DE80q]

If you really don't want to deal with the 45-1 divider board stuff, you can always use the 60-2 trigger wheel that's integral with the rear crank seal. I think it's from a VW Polo 1.4T or something. Details can be found, and I think Marc might even have them in stock.

I had looked into those, and as Shawn said, they are rather pricey. I figure that with Eric and Shawn helping me out with the electronics part of this setup, I might as well just build the board.

I can weld(mig, tig, and stick) do machine work, and just about anything mechanical on a car, but when it comes to soldering, I just cant do it. So a huge thanks to Eric and shawn for doing all that for me.

[westco4k]

im running MS3 on the freshly swapped 4000 though I haven't managed to get it started yet im not exactly a megasquirt noob but I am new to the ignition side of things so im still trying to figure out my configuration. I have confirmed my injectors are spraying, I have a nice powerful spark, tach signal is good and all the sensors are functioning correctly but it wont even try to fire when cranking. . . im posting here because I was hoping someone who has fired a 5cyl on just a straight hall effect, 5 window ms setup could give me some insight on the ignition configuration. That's the only thing I am unsure of at the moment making me believe that's where my problem is. I know it needs to be set to trigger return but what about the trigger angle offset?? will 60 degrees work for a 5 cyl? or does it need to be more like 72?? I cant find much as far as hall sensor 5 cyl setups so im really hoping you guys can help me out a little. I do plan on going to a 60-2 crank trigger soon but right now I just want to finally break this thing in on low boost and drive it a little, work out a few bugs in the new setup and then get serious with a crank trigger and more boost. any input would be greatly appreciated.

here is a pic to show im serious and not just spamming for answers. I lurk a bit over on that "other" audi forum but I imagine I will be posting over here more often from now on. this place seems more up my alley anyway.

(this pic is old, was taken before I was even ready to fire it so don't mind the cold start hole, battery cable going nowhere, etc. it has all since been fixed, just haven't uploaded any newer pics )

[DE80q]

Well, mine is MS2, and Shawn's are MS1(unless something changed I dont know about). I will have to look at my setup in the AM, I'm at work now.

[vt10vt]

MS1/2/3 this doesn't matter. I'm on MS2, ran the same setup on MS1. It's all the same except that MS1 uses trigger angle additions but that's not relevant here or to most anyone so I'm not even going to get into it.

I'll give you the long of it, if you want the short of it skip to the end for the easy/copy cat answer. But that's not what some of us are about is it?

By setting your trigger angle you are telling the ECU the relationship between when it sees events from the hall effect sensor in the distributor and the rotor being "centered" on the post for the respective cylinder you are firing.

The first thing is that the trigger angle requirements are determined primarily by the processor speed and by the desired range of advance. So if you had an ECU that could do calculations at the speed of light and wanted a maximum advance of 40* Before Top Dead Center (BTDC) then your trigger angle could be only 40*. But math takes time (especially for me ) so you need some space and time built in there for Megasquirt to do it out.


*ASIDE/IGNORE* VEMS still needs the same minimum trigger angle (fuck whatever VEMS calls it, it's Megasquirt based and you know it; it's a trigger angle). I don't know if it's processor limited or not, you wouldn't think so because it can read fast enough to keep up with a 135 tooth flywheel but I'm not sure.


So if you were to set your trigger angle at, say, 60* in TunerStudio, you are telling Megasquirt that when it sees a pulse from the hall sensor it is 60* from the next time the distributor rotor is centered on a post. Couple important things to remember here are that in basic trigger mode like you're running Megasquirt has no idea which cylinder it is actually firing, all it knows is that 60* from when it sees that pulse the rotor will be centered on a post. The rotor making contact with the distributor cap is the only thing that dictates which cylinder the coil ignites. Second is that with the motor set at TDC the rotor is centered on the distributor post for cylinder number one. In reality you don't really want the rotor centered on the post at TDC but we'll get to that in a minute. Third is that you are primarily dealing with the relationship between the sensor and the windows in the distributor. The position of the engine does come into play but trigger angle is primarily the relationship between the sensor and windows.

Megasquirt will then make calculations based on the current engine speed to tell how long it will take for that 60* to happen, and based on that time calculation it can adjust timing. Using arbitrary numbers for example's sake, if you're at idle and the hall sensor is moving 60* every 6 milliseconds, and you want the cylinders firing 10* BTDC the ECU would calculate the distributor is moving 10*/1millisecond based on the speed it is seeing events from the hall sensor and would fire 5 milliseconds after the pulse from the hall sensor comes. Thus the rotor would have moved 50* in that 5 milliseconds igniting your cylinder 10*BTDC. So if you commanded 0* advance at the same RPM Megasquirt would wait 6ms after it sees the pulse from the hall because in that 6ms the rotor would have moved 60* and thus be firing directly in the center of the rotor, which means our engine would be at TDC. Remember that when set at TDC our theoretical engine will have the rotor centered on the post attached to cylinder 1. Thus when cylinder 2 is set at it's "TDC" the next window will have sent it's pulse 60* and 6 milliseconds ago giving Megasquirt that 6milliseconds advance warning to calculate how fast the engine and thus the rotor are moving, time out dwell and then fire at whatever angle.

So hopefully what the trigger angle is doing makes sense, if not go read the megamanual front to back again a few times haha. Now on to where to set it.

This is where the theoretical engine needs real world tweaks. If you look at a spark map, you generally run 10-50 degrees of spark advance (ie degrees BTDC/Before Top Dead Center) depending on RPM, manifold pressure, temperature etc. The angular relationship between the rotor and points is the limiting factor here. Look the outer circumference of the rotor edge in relation to the entire 360* of the distributor and you'll see it only makes up a fraction of that total 360* of rotation. The size of the rotor edge dictates available engine advance. Thus the angle of the rotor on the point for cylinder #1 with the engine at TDC needs to be adjusted to compensate for the degrees of timing you actually want to run. About -19* is the angle the megamanual recommends for this ("-" =BTDC). The closest your timing will get to TDC is usually at idle, so 10-15* BTDC meaning you need to offset your rotor to allow for more BTDC timing because you won't use much (any?) positive timing. So with the engine set at TDC, your distributor rotor should actually be 19*BTDC or 19* counter clockwise prior to the actual center of the rotor.

So the process would be set the engine at TDC/Top Dead Center, center the rotor on the point for cylinder #1, then rotate the distributor housing counter clockwise (against it's running rotation) 38* to "center" the rotor relative to the angles of desired spark advance while allowing the shaft and rotor to stay in the same position. Then you would turn the engine backwards and measure the angle it takes to trigger the hall sensor. However, what you will end up with is actually in the unacceptable range, so you need to go back an extra window. Megasquirt needs either 0-5* or 60*+ and the OEM Audi distributor will fall in the range of 5-59* which won't work. So if you just keep going backwards to the next window you end up with a very high angle. In MS1 this is dealt with via trigger angle additions but in MS2/3 it's straight up trigger angle.

So set the engine to TDC. Center the rotor on the point for cylinder #1. Turn the distributor housing counter clockwise ~19*. Then turn the engine counter clockwise until a vane is at the sensor. This will be between 5 and 59* which won't work. Keep rotating backwards until you're at the edge of the next vane. Remember, the ECU only knows what you tell it so if you say 115* it knows to start calculating for the rotor it will see 115* after it sees the hall pulse, it doesn't matter if it sees another pulse/vane before it fires from the last one it saw. Overlap doesn't matter. This will work but your angle will be very high somewhere between 110* and 120* which is fine. This is where trigger angle additions come into play with MS1 but you don't have to deal with this. So that angle you measured is your trigger angle. Bam. Done. Wasn't that easy? Now you just need to use either the timing wizard in tuner studio or manually set the spark angle and use a timing light to dial in your timing exactly which can be done either by rotating the distributor or by changing your trigger angle. I recommend rotating the distributor with the engine running and a timing light on the flywheel with the timing locked at 10*BTDC in tuner studio and an adjustable timing light set to the same 10*.


So...... did you skip down here? If so go back and read

If you set your engine to TDC, your trigger angle to 115 and copy my pictures you should be running. You will still need to dial it in with a timing light but it will be pretty damn close.

Look at the mark by my thumb, that is the factory mark/tick on the distributor housing (highlighted in blue sharpie). Set the distributor in the motor and then rotate the housing to achieve the same angle between the rotor and that mark as shown in my pics. They're all trying to show the same angular relationship, just different angle pictures.




Then put your wires on as shown in these. The cap only goes on one way (correctly anyway hah) so use the two raised terminals for refrence and go from them. In the second pic the wire being lifted straight up goes to cylinder #1




Good luck,! This forum is pretty dead, for whatever reason, and you might have better luck on motorgeek as it can be a lot more budget build oriented.

[vt10vt]

Also you dont need to be running trigger return, that setting determines which edge of the distributor sensor the ecu uses during cranking. I dont remember which I'm using atm but it only relates to trigger angle in that your trigger angle will dictate if you can run one or the other or both interchangeably.

Sent from my SCH-I535 using Tapatalk

[elaw]

You want "basic trigger" mode. Trigger-return is evil... it does a lot of weird things, like trigger on one edge while cranking then the other when running.

[westco4k]

Excellent. . . Thanks for taking the time to explain it. Never read any of that in the mega manual despite reading it more than once. . . Unless I'm just blind and or extremely forgetfull. Very Informative though, and I plan on setting all that up as soon as I get off work today. Thanks again for setting this ignition noob straight. I knew this was the right place to ask.

[westco4k]

Btw maybe it's just me but it seems like anytime someone mentions megasquirt on motorgeek some fool who has never used it starts flaming about how "you should have just spent the money on a different standalone" which is a big reason why I posted here instead. It may be a steep learning curve but that's a big part of why I love it. It forces me to learn more. After building ms1 and running it reliably for many, many miles on my datsun over the last 5 years I will never go back.

[vt10vt]

Excellent. . . Thanks for taking the time to explain it. Never read any of that in the mega manual despite reading it more than once. . . Unless I'm just blind and or extremely forgetfull. Very Informative though, and I plan on setting all that up as soon as I get off work today. Thanks again for setting this ignition noob straight. I knew this was the right place to ask.

I'm glad you found it helpful!

You really have to reverse engineer some parts of the megamanual to get the whole picture, there's some gaps in "why" you do stuff, even though they cover the "how" pretty thoroughly. Eric (ELaw) is really the Megasquirt guru around these Audi parts, I have a decent understanding but he has all that and more plus a lot more electronic engineering capabilities.

FWIW we are both on motorgeek as much if not more than here, and while it's true Megasquirt gets flamed there pretty frequently, here you might be less likely to get flamed but just as likely to just get blown off by some for trying to use Megasquirt by a lot here even if you use in a constructive way like you said, not that there isn't a contingent that loves builds of all sorts.

It is what it is; far from a perfect system but like you said, it allows and forces you to learn. I've learned more about the nuts and bolts of engine sensors, management techniques and electronics from using Megasquirt than I ever could have using VEMS or 034. And if/when we decide to go with something better we will be well ahead of where most standalone users start

[vt10vt]

And I totally agree with the reliable thing. Besides setup issues, I've only once really had a megasquirt issue. I fried an ms1 processor at one point and found a bad solder joint on 5v reference pin but besides that it has always ran flawlessly and my daily 5k has been running a 1.01 original group buy board as a piggyback to the mac11 for spark control and its been flawless for months miles and abuse.

[westco4k]

agreed. all the issues I have had, past and present have been setup/wiring/configuration problems. like now. . . I had fuel and no spark before going on vacation. . . now I have good spark but it seems like the injectors aren't opening for whatever reason. . . I could be wrong on that but considering everything else is confirmed and it just spins on the starter all day without a cough or backfire, it must be fuel at this point. hoping I can sort that out today. . . I know its very close now. and im pretty good at overlooking simple mistakes so im bound to figure it out soon enough

[westco4k]

looks like the injector circuit isn't working on the brand new MS3 I bought. this was confirmed today with my old v2 stimulator. hooked it up and got nothing out of the injA, injB or fidle LED's. just to make sure it wasn't my stimulator I hooked that up to a used MS1 ecu I have and everything came to life as it should. I even reloaded the firmware and tried again to be sure it wasn't a software issue. The ironic part is, I bought that used MS1 for $100 but wasn't confident in it givin the time frame I had to get the car running so I splurged on the pre-assembled MS3 to avoid any unforeseen issues with the used ECU. over a month past my "get it running" due date and I still don't have a running 20vt. should have just gone with the old setup. lol

emailed DIY today so we will see what happens. I just hope im not out over $500 on this deal.

I may buy another bip373 and try to start it up on the MS1 setup for the time being. who knows how long it will take to get this ms3 sorted out

[chaloux]

Good luck,! This forum is pretty dead, for whatever reason, and you might have better luck on motorgeek as it can be a lot more budget build oriented.

Motorgeek has 8k+ members, TPP has 300+. Easy to see why it's relatively dead. But people can only do and post so much on the same car/project/thing etc... just a sheer volume/numbers thing.

[elaw]

looks like the injector circuit isn't working on the brand new MS3 I bought. this was confirmed today with my old v2 stimulator. hooked it up and got nothing out of the injA, injB or fidle LED's.

Are you sure it isn't your tune?

All the outputs you mention are ones that exist on the MS3X card. If you used the default MS3 tune, it may be programmed to use the MS3X outputs and not the "legacy" mainboard ones.

[westco4k]

wow thank you for that! I have felt pretty dumb on megasquirt stuff before but this one takes the cake. it starts and idles more or less now. just need to get the ignition closer and it should idle much better. I hate feeling so stupid but im very excited to have it running finally. thanks to all of you guys for all your help. hope I didn't come off as a lost cause. . . just never knew ms3 had 2 different diferent fuel outputs. Time to finally move forward on this thing again.

[DE80q]

Very nice! Glad to hear that it wasnt a bad build on the board.

[vt10vt]

Eh, most of us that build our own MS setups without an engineering background have those moments. I've had more than my fair share!

Glad to hear you're up and running! Keep us updated on how it's going and I'll keep you updated on how jealous I am of your MS3 unit. Currently: Very