I'm coming from a WRX to a Miata. I have a '92 NA with just a few simple things done so far. Obviously coming from a WRX it's a different world, but it really fun. i'm probably going to be slapping a turbo on to feel a little more alive. I am going to look into buliding up either a 1.6 or a 1.8 engine that I can transplant with a turbo into the engine bay. My question is because its a '92 it is OBD1 and I have very little experience with those years. I am a certified ase tech, but mainly on the OBD2 setups. I was looking at getting a Megasquirt 2. Obviously it would be easier to pick up a complete MSPSP system, but cash flow is a little low and I was looking at the DIY system. My question what type of vehicle plugs does the DIY system come with ot do you have to specifically ask for the one that will fit the vehicle that you will be putting it in? I went through UTI schooling and have 9 Ford certifications so I can wire pretty much anything if necessary. I just need a little information about the Megasquirt system. Thanks for the help.

 

Buy the MS for the year car you have?

 

Depends on what you mean by "the DIY system," add this cab mean one of two things.

If you mean the DIYPnP, then you buy the kit which comes with the correct connector for your year-range of car.

If you mean the old-school, basic "do it yourself" Megasquirt (which is all there was until just a few years ago, and therefore how we all did it), then it comes with no vehicle connector at all, just a generic DB-37 connector, and it's up to you to either fabricate an adaptor harness to for your vehicle or modify the vehicle's harness to fit the MS.

Please post a link to the specific thing which you are thinking about buying.

 

So it looks like the DIYPNP is the way to go then. Should be cheaper and not too much of a problem. Thanks for the help.

 

No. DIYPNP is drop-in for you car. Significantly more expensive.

 

Okay so which model should I be looking for? I'm looking to get out as cheap as possible. As of now the car is pretty much stock, short of a full exhaust system, short ram intake and 14 degrees tdc timing.

 

If you are going to go as cheap as possible, you are going to go on diyautotune.com, buy a bag full of parts, and assemble/solder the megasquirt together. MS3X. $509 to the door. + $125 for a wideband + $40 for an ECU connector. Or watch the FS ads and buy a used MS2 (my budget suggestion)

 

Thanks for the breakdown of the info.

 

A DIYPNP is ~$400-500, not significantly more expensive.

It is a MS2, you pay extra for the easy stock harness interface and the idiot proof guide. You can probably build a MS3 and a interface to the stock harness for the same price. That takes more homework, as Joe mentioned.

You should really look around the forum a lot harder before considering a MSPNP, which is different. You can do better for the same money.

 

Note that I am focusing only on offerings from DIYAutoTune, which is considered by most to comprise the "mainstream" MS product line. There are also some excellent Miata-specific MS-based ECUs available from MSLabs, however I am not particularly knowledgeable about those.



Absolute cheapest: MS1, the original:


MegaSquirt I Kits Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products - DIYAutoTune.com

For $219, you get a box of parts that you solder together yourself, and is then useless until you do a bunch of additional custom and poorly-documented modifications and also construct a new wiring harness from scratch. This is how we all used to do it, and none of us do anymore. This unit uses a 30 year old CPU running a software package that leaves much to be desired, on a circuit board that was originally designed to run throttle-body injection with a distributor and uses some really lousy, sub-optimal circuit designs. So don't so it.

Just don't.




Also ran: MS2, the original:


MegaSquirt II Kits Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products - DIYAutoTune.com

MS2 places a new CPU onto the same crappy old circuit board as MS1. The software sucks somewhat less, but it's otherwise the same old **** where you've gotta do a bunch of custom modifications to the board and live with crappy circuit design.




DIYPnP:


DIYPNP Nippon Denso 76pin Unassembled Kit DIYAutoTune.com

Now we're getting somewhere.

The same CPU as the MS2, on a new board, with less-bad circuit design. Decent software, and once it's assembled you have a plug-and-play solution with no harness fab needed. A good choice if you're skilled with a soldering iron, a terrible idea if you're not.





MSIII:


MegaSquirt III Kits and Assembled ECUs Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products - DIYAutoTune.com

Yet another new CPU tacked onto the same old circuit board from the MS1. This also adds the "X" expansion board, which finally adds native support for multiple ignition coils and injectors, PWM-based idle valves, etc., meaning you no longer have to do a bunch of custom modifications internally. Sadly, it still retains some of the crappy circuit topology from the original 1990s vintage MS1 design and you still have to build your own harness. This is an intermediate step in the right direction; cutting-edge software married to trailing-edge hardware.

To be avoided by all but the most hard-core techie types.





MSPnP2:


MegaSquirtPNP Plug-and-Play MegaSquirt Engine Management Systems by DIYAutoTune Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products - DIYAutoTune.com

This is essentially a fully pre-built version of the DIYPnP. Based on the MS2 CPU, it's an excellent choice for the '90-'00 Miatas.





MS3 Pro:


MS3-Pro Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products - DIYAutoTune.com

****.

A generic, non plug-n-play ECU based on the MS3 CPU, but with completely new circuit board from the ground up which carries over none of the shitty circuit design from the original MS1. (They even "borrowed" the crank decoder circuit design that we came up with on this forum a couple of years earlier.) This will fit any car, but requires harness-building like the old ones. Expensive and worth every penny, easily the best universal ECU on the market today. I had the privilege of running a beta version of this on my old 1990 car, and loved it.




MSPnP Pro:


MegaSquirtPNP Pro MM0105 for the 01-05 Mazda Miata, manual trans DIYAutoTune.com

****, in plug-n-play form.

Only available (for now) for the '01-'05 cars (a separate version exists for the '04-'05 Mazdaspeed). Based on the MS3 Pro design and software. The best plug-n-play available for the later-model cars.

 

Props Joe, love the breakdown.

A little confused though... is the MS3 above similar to the MS3 from MSLabs? I had thought that was the bees knees.

 

Well, in this context, the term MS3 can be used to describe a whole family of ECUs which share a common core architecture.

In its most basic form, the MS3 is a certain CPU and a specific set of software that runs on it. There is an ECU which we call the MS3, which is the basic model built around this CPU, and can be used by hardcore tech types as the foundation for building a complete ECU for a custom application. I've put a few of them into race cars.

Then there are a number of other ECUs which are based on the MS3 CPU and software, but on a custom circuit board typically designed for a specific application.

The MS3Pro and MSPnP Pro are examples of this. DIYAutoTune took the basic MS3 CPU and used it as the core of a very advanced and capable set of ECUs which are proprietary to DIY.

(Yes, the fact that there's a company called DIY, which sells products with DIY in their name, makes things confusing when we're literally taking about do-it-yourself ECU builds, as I've built in the past for myself and others.)

The MSLabs products are similar in concept to the more advanced models sold by DIY. Reverant, like DIY, designs and builds ECUs which utilize the basic MS2 and MS3 CPUs at their core, but place them on a board which adds a host of advanced features not available on the "basic" design. The only reason I didn't go into any detail about them here is that I simply don't have any hands-on experience with them.

 

I've run both the MSPNP1 and MSPNP2 in my car. I think they are both great ECUs, but if you want A/C in your car at least go with a Megasquirt II based ECU, you'll make a bit more power thanks to the larger fuel and spark tables, but the biggest difference in the two I found in the real world is idle is far more consistent and easier to tune in on the MSII based ECU, but without A/C you can still dial it in pretty well on a MSI, I just had to run a higher idle in the summer. I haven't dealt with a MSIII personally.

On a budget I would not mind going MSI in a non A/C car, but the MSII is so much better.