A summary of the Megasquirt family for newcomers
10-18-2014, 02:56 PM
#1
Boost Pope
Thread Starter
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,039
Total Cats: 6,604
A summary of the Megasquirt family for newcomers
This question seems to come up a lot, so I'm creating a sticky that I can point people to in the future. This is current as of Oct 2014, and will (hopefully) be updated as time goes on.
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.
Also, since the question comes up a lot: no aftermarket ECU will return OBD-II codes, and this includes the MS family. Those of you who live in areas where plug-in emissions testing is performed on '96 and newer vehicles will need to deal with that. Many people swap ECUs (and injectors, etc) once ever year or two, a few die-hards come up with custom "parallel" solutions that place the MS beside the stock ECU, letting the former run the engine and the latter talk to the OBD-II test station. This is very hard to do right.
Now, the breakdown:
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 do 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.
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.
Also, since the question comes up a lot: no aftermarket ECU will return OBD-II codes, and this includes the MS family. Those of you who live in areas where plug-in emissions testing is performed on '96 and newer vehicles will need to deal with that. Many people swap ECUs (and injectors, etc) once ever year or two, a few die-hards come up with custom "parallel" solutions that place the MS beside the stock ECU, letting the former run the engine and the latter talk to the OBD-II test station. This is very hard to do right.
Now, the breakdown:
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 do 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.
Last edited by Joe Perez; 10-21-2014 at 12:50 PM.
Reply
7
7
10-19-2014, 09:22 PM
#2
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,660
Total Cats: 3,011
For posterity:
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.
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.
Reply
0
0
10-21-2014, 05:42 PM
#11
Boost Pope
Thread Starter
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,039
Total Cats: 6,604
Likewise, no version of the MS1 is capable of running more than two injector channels (meaning you must run batch-injection), and basic MS2s require custom modification to drive more than two injector channels.
All ECUs based on the MS3, as well as the more advanced MS2-based units, come out of the box ready to drive four (or more) injector channels, and two (or more) ignition channels.
Last edited by Joe Perez; 10-21-2014 at 07:30 PM.
Reply
0
0
10-21-2014, 06:18 PM
#14
Boost Pope
Thread Starter
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,039
Total Cats: 6,604
I was going to link you to the specific thread in which I described an advanced version of this mod, however I see that ImageFrame has fucked me yet again, and all of my diagrams are gone. I'll see if I can resurrect those sometime next week after I'm back home.
That said, don't build an MS1. Seriously, God kills a kitten every time you even think about it.
Reply
0
0
10-22-2014, 04:07 PM
#16
mkturbo.com
iTrader: (24)
Join Date: May 2006
Location: Charleston SC
Posts: 15,177
Total Cats: 1,681
Yes. Having performed suitable internal modifications to bring out two ignition channels, then yes, the MS1 will control both fuel and ignition directly.
I was going to link you to the specific thread in which I described an advanced version of this mod, however I see that ImageFrame has fucked me yet again, and all of my diagrams are gone. I'll see if I can resurrect those sometime next week after I'm back home.
That said, don't build an MS1. Seriously, God kills a kitten every time you even think about it.
I was going to link you to the specific thread in which I described an advanced version of this mod, however I see that ImageFrame has fucked me yet again, and all of my diagrams are gone. I'll see if I can resurrect those sometime next week after I'm back home.
That said, don't build an MS1. Seriously, God kills a kitten every time you even think about it.
Reply
0
0
10-22-2014, 08:15 PM
#18
Senior Member
Join Date: Sep 2011
Location: Sierra Vista, AZ
Posts: 1,201
Total Cats: 295
Thanks for putting this together, definitely helpful!
Two noob questions:
1. It appears that the MS3 Pro is only available assembled?
2. It should be possible to build a "PNP" jumper harness for the MS3 Pro using the DIYBOB ND76pin to connect to the factory 1.6 harness?
Two noob questions:
1. It appears that the MS3 Pro is only available assembled?
2. It should be possible to build a "PNP" jumper harness for the MS3 Pro using the DIYBOB ND76pin to connect to the factory 1.6 harness?
Reply
0
0
10-22-2014, 09:34 PM
#19
Boost Pope
Thread Starter
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,039
Total Cats: 6,604
Clearly I need to update this thread to include a preface which discusses the CPUs themselves, and talks a bit about the 3.0 / 3.57 mainboards... So little time.
The base version of the MS3/X (the one that uses DB-37 connectors) uses the same Rev 3.0 or 3.57 PCB as the MS1 did. Thus, while it offloads much of the functionality (spark, INJ, idle, etc) to the X board, it uses the same brain-dead CKP input circuit, and includes a second, equally bad copy of it on the X board for CMP.
This is one of the biggest reasons why Bruce and Al need to be tortured to death and then have their graves desecrated by the surviving members of GWAR.
I'd say that's a reasonable assertion, though of course the MS3Pro, not being a PnP ECU, targets a somewhat different audience.
If you have a '90-'00 car with the original engine, then the DIYPnP or MSPnP2 are really all you need. The only reason* I'd upgrade to an MS3Pro for these cars would be if you are running an '01+ engine, so you can control the VVT natively.
If you have a whole '01-'05, car, then I'd recommend the MSPnP Pro, which is an MS3Pro in plug-n-play form.
1: Correct. The MS3Pro, unlike most of its predecessors, is sort of a "closed box" system. It is available only fully assembled, and really, there's very little reason you'd need to be inside the case, other than to install pullup resistors on the crank and cam sensor lines. (Suggestion to DIY: Make these software-selectable via an AQW212 controlled by some of the ten-gajillion surplus GPO pins available.)
2: That's not a question. But it's extremely easy to adapt the MS3Pro's included generic harness to pretty much any vehicle wiring harness. Here's what mine looked like plugged into the factory harness in my 1990:
This is one of the biggest reasons why Bruce and Al need to be tortured to death and then have their graves desecrated by the surviving members of GWAR.
If you have a '90-'00 car with the original engine, then the DIYPnP or MSPnP2 are really all you need. The only reason* I'd upgrade to an MS3Pro for these cars would be if you are running an '01+ engine, so you can control the VVT natively.
If you have a whole '01-'05, car, then I'd recommend the MSPnP Pro, which is an MS3Pro in plug-n-play form.
* = or if DIY gives it to you basically for nothing, which is how I got mine.
2: That's not a question. But it's extremely easy to adapt the MS3Pro's included generic harness to pretty much any vehicle wiring harness. Here's what mine looked like plugged into the factory harness in my 1990:
Reply
0
0
