So assuming MS-I for now ... this is the parts list I'm looking at:

• MS1357-C Assembled Megasquirt-I with V3.57 PCB
• MOD_13571GDSM Preconfigured 4G63 / Miata ignition output
• JimStim-C Assembled JimStim diagnostic board
• MSPiggy 18" wiring harness pigtail
• IATwPiggy IAT Sensor (if not sharing temp signals with the MAF)
• 38NPT-Bung_S Steel Bung for mounting IAT sensor (Alumimum or stainless also available)
• TuneCable 6' DB9 tuning cable (unless I have one in my junk pile)

In addition, I need the boomslang extension, which I can splice into with the MS Piggy. I don't quite have all those details straight, but I'll figure that out later.

Now my question is, considering that I'm running stock, how important would it be for me to have a wideband? Can I tune via default maps and educated guesses and then wait on the wideband until I start making engine mods (turbo!)? My goal is to have no CELs. I want to be able to drive the car right up to the emissions testing center and pass the OBD-II test without any issues.

 

What part of 2 identical simple circuits did you not understand? Reread my post.

 

Trying to comprehend what you wrote is making my head hurt. Seriously, is English your primary language?


Any details on what, exactly MOD_13571GDSM consists of? I ask because, given that you're doing a parallel install, some other modification might still be necessary. For that reason, it might be preferable to go with the 3.0 PCA as opposed to the 3.57.

Since you have an NB, I would suggest that you at least consider the MS-II CPU. It'll pay for itself in the savings you realize from not having to procure and install an NA CAS and associated wiring.

I wouldn't even dream of tuning a standalone ECU without one, even on an otherwise stock vehicle, but that's just me.

 

Finals left me brain dead. I haven't been able to talk straight for the past week

Anyway, electrical stuff isn't my forte, so I tend to ask more about it before I tackle anything regarding electronics. The last thing I would wanna do is **** something before i used the wrong capacitor or I didn't read the schematics for the circuits right (i.e. where things connect and what to follow)

 

The MOD_13571GDSM code is for Miata / DSM ignition mods with the pull-ups on the ignition inputs and 5 volt ignition outputs. Not quite the same mod version we use on the MSPNP but close.

We'd need to do a bit more testing in-house before we offered any MS-II products set up in our shop for the '99 and later Miata. We stick to mods we've either tested in-house and can guarantee they'll work or a couple mods that have had very extensive testing and we have a good way of bench testing.

 

I have been following this thread with interest, as I am an NB'er. I have both a 95 and a 96 CAS. It appears that the 96 will offer some benefit over the 95 CAS? I should add, I know the 95 is a 26K mile CAS, whereas, I can only assume the 96 has 150K on it. Are miles an issue?

 

I agree with you completely ... but as Matt said they don't have one built yet, and as much as I love a good DIY project, I don't think I have the time to learn to build my own MS-II and do it right.

I've been reading the threads of all the folks who are much more experienced than I when it comes to engine management and building circuits, and I suspect that it would take me a long time to get it built (I travel all week for work, and only have Fri afternoon - Sun evening at home. I can only devote so much time to car projects). By then DIY might just have one for sale.

Now, if Arga or AbeFM would like to build it and come to Seattle to help me install / troubleshoot a parallel install ...

Otherwise, I'm thinking an MS-I is going to be more manageable for me, even if I do have to do some extra wiring.

 

Cool. I'd not heard of this particular mod package- the OP didn't mention the inputs and I couldn't find a schematic (or even a description) on the website.

What mods do you typically do to the boards?

The reason I ask is that, insofar as I can tell, the hardware side of it would nearly identical for both MS1 and MS2 (and for that matter, NA vs. NB), at least insofar as the "basic" and "intermediate" mods are concerned. The second trigger input is the only one I can think of off-hand that changes- JS10 vs. JS8. Even EBC, Constant Baro, Launch Control and TachOut can use the same pins on MS2 as on MS1. Knock would be a different pin, as would table switching. Same circuit, just a different CPU pin. (and truthfully, I don't expect you guys to be enabling all those features, as getting them to work is probably outside the scope of your average PNP customer's comfort range)

I do understand needing to test the product prior to shipping however. I wonder if this might be a case where a collaborative effort would be in order? IOW- mod a 3.57 PCA to your "standard" Miata spec, then have a third party document the process of getting it reworked and operating to MS-II specs. I don't think it would be all that tricky, particularly if said third party also built and documented the Boomslang harness prior to delivering the complete assembly to the end-user. Said third party might even be able to find someone with an unmolested '99-'00 in the San Diego or LA area willing to be a guinea pig, in exchange for receiving unit #2.


In terms of their design, the '95 and '96 CASs are absolutely identical. The same part. BPE8-18-230. Mazda did not change the cam sensor until '99, even though they added a crank sensor in '96. All Miatas '94 to '97 got the same cam sensor. I would go with the lower-mileage unit.

 

I was confused and misread crank sensor for cam sensor earlier in the thread. Thanks for clearing that up.

 

You should definitely get one IMO. It pays for itself pretty quickly by taking most of the guesswork out of the tuning; it saves a lot of time and frustration. A WBO2 coupled with data logging (megatune) and megalogviewer is a great tuning tool. I love mine.

You can damage a stock motor with an overly lean mixture. The turbo makes things riskier of course, but that does not mean you are safe with no turbo. I guess you could just load up the very conservative PNP map and be OK, but, you are really going to want one eventually (with the turbo), so why not play it safe now? Plus even NA (no turbo) you can get it running better versus the PNP map, and it gives you a chance to get your tuning skills in shape before the turbo goes in.

In short, play it smart, get one.

 

Good point. The biggest reason I'm planning to install the MS now is so I can learn to tune it before I get the turbo. Wideband it is.

 

Mod codes are not listed on our website - when special ordering something, we usually set up the order by email and have a chance to explain to the buyer what they are.

The thing with the MS2/Extra mods is that we'd like a bit more experience with what could potentially go wrong with the mods before we ship a unit. If there are any hidden "gotchas" to either the mods or the code, we don't want to find out from a frustrated customer first if it can be avoided.

For example, not long after the MS2/Extra direct coil control mods came out, a bunch of controversy erupted over whether VB921s needed 330 ohm or 750 ohm resistors, with people arguing over issues with the larger resistors not starting in cold weather and noise issues. If we'd picked the wrong version of the mod when it first came out, we'd have had quite a few recalls on our assembled units. So we waited a bit, and did some testing of our own. Those Bosch BIP373s we sell, we did all kinds of crazy things to make sure we knew what could go wrong - trying to fry them with too much current, sticking them in the freezer, virtually every torture test we could imagine.

 

I've not been keeping up with my beloved MiataTurbo.net. Sorry folks.

The biggest troubles I had with the whole standalone were 1) not enough electrical damping on the VICS valve. Needed a good diode, might need more than I gave it. It was masked by other problems. 2) The input circuits. As mentioned elsewhere, I just copied the OEM circuit. I figure it's reliable enough for mazda, it must be reasonable. So far I've had no reason to doubt it.

Honestly, in a no-holds-barred build, I'd do a multi-toothed wheel, though I'm not sure about decoding the VR in the MS verses on the sensor. But it seems to work, so I can't really argue with that. The cam sensor is used so poorly by the MS I don't know why they bother. In fact, there was a bug in the code where it ALWAYS thought it was on cylce one, never two, and it didn't change anything, except the motor starts slower.

As fas as the inputs go, it's really very simply, a handful of resistors, one cap, and one 8 pin chip. That gets you from DB37 to CPU.



Still bitter about it? :-) I'll either bring by the two liter growler, or you come down and get it. :-) Last night we had 4 MS folks in the house - with 5 MS between them. Three mazdas. Pretty good times, though it's shocking how fast that bores the girlfriend. :-)

That's my biggest issue with parallel installs. You're always guessing what's going on.

The MS-II does indeed have closed loop idle. They brush over the details and call it a PID closed loop, when really it's just some weird, poorly written function the takes an input and varies an output (not quite at random), but many people have it set up well enough. But my MS idles so smooth, I've found it much more prudent to just raise the RPM 100, and let the loads come as they may. It's never flinched or misbehaved since the switch.

The crankwheel is the way to go. I only did the stock sensors to prove it could be done.


The wheels on the later car are identical, only the phasing varies with VVT. Unless the angle varies so much as to move the pulses out of the range between the two crank teeth, there's no issue - as you said, it's only used for determiing TDC. As I understand it, you could just put it on any NB miata, but no garuntees. However, if there was an issue, I'm pretty sure just a small phase difference (moving either sensor a few degrees) would solve it.



Lastly, just a bit of advice. If it were me, I'd run a standalone. More of my problems came from either wiring or operational issues trying to get the two computers to work nicely together. If I was concerned for smog, I could put the system together with a well thought out boomslang, and just swap to the OEM ECU (and maybe injectors if applicable) for the tests. Absolutely not worth the headache.

Someday, someday, I'll write a 99+ guide.

 

I spent a couple hours Friday night with the soldering iron and I have a "functional" MS-II board.

I am about to begin:

"Input Section Construction & Testing

42. Remove the processor from the 40-pin socket - use a thin screwdriver and pry it from the socket, first one end, then the other - place it back on the foam pad it was shipped with. Now, you are going to install all of the input sensor components. "

What I'm having trouble with is:



On a '99, do I want to install this jumper?

Also, about the crank input I want to duplicate for the cam. Could someone explain what I'm doing here? This is where I am really lost. If someone can give me pin by pin instructions () I will make it worth your while; beer, MS Parts, etc.

Thanks

 

We don't use a stepper IAC so you don't need that mod. Can't answer your input mod question, sorry.

 

Which circuit did you build for the crank input?

The most basic cam input circuit, which most people use, is the one described in DIY's How to Megasquirt your Mazda Miata article. The article is written for an NA, however the electrical characteristics of the sensors on the NB are virtually identical. Alternately, you could follow the instructions in the MS2Extra manual. Their circuit is, in my opinion preferable, since it optoisolates the CPU and is more or less identical to the primary input circuit: http://www.msextra.com/ms2extra/MS2-...tion.htm#2hall

 

Thanks guys.

I built both inputs for the crank signal like the manual suggests. From Braineaks's DIY it looks like I didn't need both. Is that an issue, or can I just jumper what I need active?

The circuit here:
http://www.msextra.com/ms2extra/MS2-...tion.htm#2hall

I think I understand it. I apologize for being so new to this.

I understand where the resistors go, and what to solder to with JS10 for example. Where I get lost is with the meaning of the numbers next to the right angles in the diagram? Are those the pins for the 4N25 opto isolator? If so, where do I want to build that circuit? Proto area? If so, I think I have it down.

Thanks again.

 

You built both the VR and the Opto input? No problem. Leave the VR circuit alone and just jumper the opto circuit.

Again, you can make the CMP input circuit simple or complex. If you do it with just the two resistors like everybody else, that's simple. Or you can build the one linked to above, and personally I think it's a better design.

The numbers are indeed the pin numbers on the 4N25.

Are you building standalone or parallel?

 

While I can see Abe's point on going parallel I don't agree with him 100% once you have control of idle, fuel and spark I don't see how the OEM ECU can effect anything other then the EGR valve.

But, as Abe mentioned I built a boomslang like harness with a couple SPDT switches that allow enabling and disabling the megasquirt. I also have a MS-II built, I used the standard spark outputs and 2N2222A transistors for inputs coupled to TSEL and JS-10. I hope to test the system next weekend.

Here is the circuit for a Parallel install, Arga designed it.

 

Exactly. YOU don't see it, but the fact is it still happens. Listen to Abe. He knows his ****. I ran MS parallel on my 99. I had too many problems. I'm going standalone now to get rid of all the nonsense and headache.