OK boys and gays, time to make a fool of myself. I suck at all electrical stuff and I know nothing at all about engine management. So here it comes: Are all Megasquirt units the same? The reason I am asking is that my Porsche driving friend built a Megasquirt unit some time ago and now asked if I want it. Do you build the Megasquirt for a specific car model or are just the connections different?

 

same but not equal.

there are 3 versions of the board itself: 2.2, 3.0, 3.57

the software has different firmwares

the modifications to the board to drive different coils, read the rpms and whatnot are different.

 

There's also two totally different CPUs- MS1 and MS2. They're largely comparable in terms of capability- different codebase and a few differences in featureset. It takes a while to learn the pros and cons of each. The MS1 is more common (largely because its cheaper) and actually has some features that the MS2 does not. The MS2 has better support for OEM NB sensors and slightly better fuel control, it's just not quite as "mature" a product in terms of the code being fully tested and all the features working properly.


The three PCAs of which Brainey speaks-

The 2.0 is obsolete. Forget about it.

The 3.0 is the "standard" board for nearly all DIY builds.

The 3.57 is functionally identical to the 3.0, but it uses surface-mount components and is only available pre-assembled, not in kit form.

 

Whats a meqasquerts?

 

i was waiting for joe to post i didnt actually wanna type out all the differences.

 

I should clarify that by CPU I'm speaking of the actual CPU chip itself. Assuming you have a R3.0 circuit board, you can choose to put either CPU onto it, and run the code appropriate to that CPU.

With a Miata, whether you choose MS1 or MS2, you'll probably be using a build of the code called "Extra." There's an MS1-Extra and an MS2-Extra codebase. A good place to learn about the two is at their respective homepages:
MS1Extra: http://www.msextra.com/manuals/MS_Ex...nual_Index.htm
MS2Extra: http://www.msextra.com/ms2extra/

In addition to info about the code, there's also a lot of helpful info in there about the hardware modifications you'll be making to the MS circuit board to accommodate vehicle-specific I/O.

 

Thanks a bunch for all the help guys! Armed with this info, I am going to find out if I can use the Megasquirt he has. Is so: sweet!

 

Im going to ask a dumb question now:

After reading Joe Perez's links on MS1 and 2 I got a bit confused, so to verify

The MS1 is just a fuel controller whereas the MS2 is a Fuel and Ignition controller. (The MS2 being the only actual 'standalone' ecu.....)???

I need verification not flamification!

 

Absolutely wrong. MSI does fuel and spark and whatever else you need. It's a fuel standalone ecu.

 

The original design of the MS1 (and this is going back many years) was fuel only. This was a limitation of the software, not the hardware. Presently, using the MSNS-E (Mega Squirt'n'Spark Extra) code, the MS1 is a fuel and ignition controller.

Both the MS1 and MS2 are capable of functioning as fully standalone ECUs. Their I/O capability is nearly identical. There are a few advanced features that are only available on one or the other (MS1 can do a few things MS2 can't, and visa versa) but for 95% of applications, they are functionally identical.

The MS2 uses a newer microprocessor, and the code is written in C, as opposed to pure, God-fearing Assembly. The MS2 does a slightly better job of computing fuel pulses accurately, so if you want to use 1,000cc/min injectors and still pass an emissions test at idle, you'll probably need MS2.

I'm not aware of a single comparison chart between the two, but here's some good reading on both:

http://www.msextra.com/manuals/MS_Ex...nual_Index.htm
http://www.msextra.com/ms2extra/

 

fix the typo Joe. "you'l probably need MS1"

 

Here is a pretty good feature comparison table, http://www.msextra.com/ms2extra/MS2-...l.htm#features

 

Alabama.jpg

 

Yeah, meant to say "you'll probably need an MS2" there. Fixed.


Although there are a few functional differences, the MS1 and MS2 are basically two different ways to accomplish the same functionality. The code on the MS1 is older and more mature, meaning it's in some ways more stable and less buggy. The MS2 is, in my opinion, a good deal more complex and confusing, simply because the MegaTune implementation for MS2 has a lot more extra features that normal humans never use.

Both will do the basics- fuel and spark, EBC, WBO2 w/ autotune, knock detect and retard, etc... The MS2 does have a couple extra features (such as flex fual capability and a more advanced knock retard system), while the MS1 has a couple of extra features (like water injection control) that MS2 lacks.

If you have an NB, and wish to run on the stock cam and crank sensors, MS2 is easier to get running in this setup from a software standpoint.

 

I'm planning on running waterinjection on my '00. What would be my best choice ? I want to use the MS standalone.

 

Best choice for performance? An Aquamist 2d and a MS2.

The MS2 is required to use NB sensors. However the MS2 does not natively support WI like MS1 does. However, you can pretty easily emulate the MS1s WI capability with a couple of transistors and a "spare" output. Basically, turn on an output when MAP = 100 kpa. Thet output closes a pair of relays, one to turn the pump on, the other to connect a second FET driver to one of the fuel injector channels.

Realistically however, these valves are expensive. You can get a whole DevilsOwn progressive WI system for $330. The Aquamist systems run $800+

 

Cheers guys