Why NOT Microsquirt??

Kind of a dumb question, but when talking about MS and the DIY injection systems, it seems as if Microsquirt is almost never brought up.

It's a pre-assmebled unit, and the overlay harness to hook is also pretty reasonable. It does fuel and spark with nominal inputs- pretty much what everyone wants.

But it's almost never brought up here.

Why is that?

The answer for me was not enough outputs, and no stepper motor control of iac.

well.. most (all?) of the DIYPNP kits are based on the microsquirt module. Not that the module is the same as the board in the Microsquirt, but they're close.

My understanding for the Microsquirt is that it's limited in terms of I/O circuits/types, certain types of ignition, and some of the more advanced injection configurations. Basically, you can do a lot with one, but not all of it all together.

Dusterbd13 wrote: The answer for me was not enough outputs, and no stepper motor control of iac.

Other than IAC controller, what more did you need than fuel and spark? (I didn't read your entire thread, so probably missed that detail)

There are some good ways around the lack of idle air control- we didn't have it on our challenge car, and got it to work well enough. But I'm planning on looking at it closer for other things.

bluej wrote: well.. most (all?) of the DIYPNP kits are based on the microsquirt module. Not that the module is the same as the board in the Microsquirt, but they're close. My understanding for the Microsquirt is that it's limited in terms of I/O circuits/types, certain types of ignition, and some of the more advanced injection configurations. Basically, you can do a lot with one, but not all of it all together.

I think my question more is- given those limitations (and that many other EFI systems have the same issues), the cost is still quite cheap.

I paid $400 for an Electromotive TECII back in 2002, and other than the attached coils, the MicroIII does the same things, and costs less in today's dollars. Actually does more- as it capable of taking MAF and WB inputs. I know the WB part was a big problem with TECII.

Here's the comparo link.

Mircosquirt would do just about everything needed for the Challenge Roach except fit in the budget. I would attempt assembly of a kit, but my luck has been pretty sucky lately . . .

In reply to Strike_Zero:

THAT is a really helpful link to a page I have searched for a few times but never found.

I have been wanting to install one on one of my bikes but I need to assemble my MS2 before buying another to have it sit on a shelf. No actual input here.

Strike_Zero wrote: Here's the comparo link. Mircosquirt would do just about everything needed for the Challenge Roach except fit in the budget. I would attempt assembly, but my luck has been pretty sucky lately . . .

that's great info!

Although I thought that the MqS didn't have idle speed control- that chart suggests that it does.

I'm also interested in the $250 board idea. Well... somewhat. Getting the module plus he plug and pins- one could modify the production harness to work. I saw on ebay you could get the connector plus pins for a good cost.

I've often been recommending the MicroSquirt to customers who:

• Are looking for an assembled, wire-in ECU instead of a kit.
• Don't need sequential injection or the heavier duty injector drivers found in a full size MS2.
• Are using a PWM idle air control valve or no idle air control.
• Don't need sequential injection or other MS3 specific items.

And both the DIYPNP and second generation MSPNP use the related MicroSquirt Module at their core. I think the main reason we don't see people looking at it more often is that it was originally marketed more towards motorcycle and powersports applications, and some people seem a bit surprised to realize it works fine on automotive-sized engines too.

In reply to MadScientistMatt:

But I don't seem to see that recommendation here. While I am pretty sure that I can build a kit, I know I would start with the MqS first- best value you guys have.

A question, though- on the chart, for the MqS module column, under number of injector channels- there's this line:

can be expanded to 4 with modifications

Does that mean that 4 cyl sequential is possible?

(and I guess that I should ask if the 2 banks fire once or twice (or 4 times) per cycle....)

I didn't realize how cheap these were- would a MicroSquirt be a good choice for an N/A rotary application?

With the MicroSquirt Module, yes, you can get four injector channels with some external circuitry and run them sequentially. We did that in the MSPNP.

With the regular MicroSquirt, no, two channels is all it has for fuel. You can get four spark outputs out of it with the current code, though.

And yes, it can run a rotary - it'll even do the leading / trailing ignition split.

In reply to MadScientistMatt:

Interesting.... Hmmm

Because MS2v3.0

bentwrench wrote: Because MS2v3.0

Can you be more specific? When I read the charts, the gains don't seem to add much.

alfadriver wrote:

bentwrench wrote: Because MS2v3.0

Can you be more specific? When I read the charts, the gains don't seem to add much.

because it is more easily modded for extra inputs and outputs due to its slightly larger board size and space set aside specifically for "Prototyping"

Also you can buy this board:

http://www.jbperf.com/p&h_board/

or this one:

http://www.jbperf.com/quad_ign_inj/index.html

To extend the injector options available with the standard MS2 board and they'll fit into the MS2 case keeping the install fairly compact.

In reply to Stefan (Not Bruce):

Ok, that makes sense.

But how much does that buy someone? One gives you 4 injector, the other gives you 4 coil drivers. Huge for a coil pack V8, but other than really good emissions, I'm actually not 100% on SEFI. So for a 4 cyl car, well... Unless you are doing some very fast and late updates to the fuel, SEFI's biggest benefit would be OVI charge cooling- which really would need some good dyno time to tune.

The other thing- do those boards work with the MqS Module? With that being mostly assembled, it still seems like a great deal. So the difference between the two systems don't seem that different.

Anyway- getting into those details- it seems as if one can get into analysis paralysis. One really needs to know what they need to do so that they select what they need vs what is cool to have and would never use....

BTW, you guys do know that many OEM's as well as suppliers are hiring specialist like you. It may become just a career vs. a fun job, but some of the depth of knowledge you know would go a long way.

On a different tangent- do the MS systems have actual code to read? Like the C code or something like that? If I go that direction (if ever), I'd really like to see how the code works directly- just so I can calibrate it better.

Yeah, the source code to the various MegaSquirt firmware versions is available.

Here's a bunch of MS3 firmware: clicky.

Which one of the files is the code that runs the module? Lots of files in both firmware and sourcecode files.

The MicroSquirt Module would be using the MS2 code, which you can download here.

http://www.msextra.com/downloads/

The source code is in the "ms2extra" folder inside the main ZIP file. It is, however, split into a bunch of separate files. Start with "ms2_extra_main.c". This thread gives some explanation of the tools used to compile it.

http://www.msextra.com/forums/viewtopic.php?f=91&t=43601

In reply to MadScientistMatt:

Thanks- and looking at that- looks nicely documented inside the code.

So some of the code is in the _main.c file, but each sub module has it's own C book. Can, EGO, Idle, Ign (a few), inj, etc...

I guess I need to get it, and play with it.

In reply to alfadriver:

The first board is a slightly better way to manage low impedance injectors, instead of a "flyback" board.

I agree with the SEFI thing, but it seems like its a feature that's touted by quite a few as the end all be all when comparing EFI systems.

I could see options like this potentially helping with oddball engine configurations like rotaries or 3/5-cylinder motors, dual injector setups on 4-cylinders, etc.

I use a Microsquirt v3 on everything that I can. The only time I don't is when I can't do something then I go right to MS3-Pro. Fooling around witht the kits (even for a pro assembler) isn't worth the hassle at their respective prices.

alfadriver wrote: BTW, you guys do know that OEM's as well as suppliers are hiring specialist like you. It may become just a career vs. a fun job, but some of the depth of knowledge you know would go a long way.

Link me to these opportunities.