1995 Miata - MS II V 3.0 (DIY EFI) - Running MAF
 

Hi Guys,

Wow time has passed since I posted my intro https://www.miataturbo.net/meet-gree...-thread-83161/

Since then I have been making some small progress with the Mega Squirt project, I have finished the ECU build, completed the Y harness ( which I built to test inputs and outputs before going full stand alone) The ECU, Tuner Studio and Logging all work, as well a few of the basic inputs like, TPS, CLT, RPM are working well.

Class rules for STS state that I must use OE sensors for the inputs to the ECU, so I need to sort out how to use these to tune the Mega Squirt, I assume that I will be using the MAF? If so my next task is getting to know the MAF and values and how I can use these signals to tune the Mega Squirt.

I have searched for many hours but I can not seem to find any information about the Voltage output values for my Miata MAF ( B6BF 197400-031 ) Does anyone here know ? I assume that this would be an option for the PNP guys to use the MAF ?

Or can someone shed some light on how I might be able to get around the MAF output ? Like maybe using TPS ?

Or can I use MAP or TPS - to reverse engineer the MAF output ?

Any help is much appreciated

Dave

Techsalvager here on the forum is running with the MAF as well. You might want to contact him or maybe he'll chime in.

What are the units of the inputs to the table? V and CFM?

a bunch of STS guys were doing it. some dude on M.net was building MSes from them all, had some PNP unit to fit into the stock ecu that took care of the conversion thing. I never followed it.

maybe Andy Hollis?

I believe that I need to create a 1024 element table of the air flow versus voltage, measured in grams per sec / 0-5 Volts.

Thanks !
I will send him a PM

Oh hey good call on Andy... never even crossed my mind, I will.
Thanks

The STS ones were all for the 1.6L miata I think. Justin Mitchell (JustinHoMi) and Andy Pfotenhauer were the ones building them but neither have built any recently.

I know Justin was looking into building the 1.8L stuff back when he was building them but I don't know if he ever got around to building/testing one.

Interested in seeing where this goes since my 94 needs something like this.

I think those guys stopped making them as they changed the rules. Reading the current rules 14.10.F.1, 2.a,b, says nothing about replacing the factory ECU. Says you can reprogram factory ECU or piggyback it. I don't see the old rule of "it's OK to standalone as long as it fits in stock case".

And since you can't add sensors, you can't run MAP. As you mentioned though, you can use a MAP to create a table to document flow from the MAF. Once you have it running well on the MAF, piggyback the stock ECU so it does all emissions stuff and have the MS control the engine. Remove the MAP use from the system of course.

Megasquirt is considered "reprogramming" via hardware and is legal for pre OBD2 cars.

Yes and it must be piggybacked. It can't be a stand alone ECU installation. And the piggyback harness has to be a Y installation. No cutting and splicing. This means you would be able to unplug the MS from the car and run off the factory ECU.

No you can still run the megasquirt in the stock ECU case legally. The rules have not changed on that.

yeah, this was my understanding, that the MS was fit inside the stock case.


here's the dude I was thinking about: http://forum.miata.net/vb/showpost.p...&postcount=988


https://www.miataturbo.net/attachmen...ine=1456064822

he used to have a site dedicated to it, and would build them for others, but it seems to not be available anymore: http://www.justinmitchell.net/docs/d...ts2_megasquirt



he posted something about it here in 2009, but never read anything about this since:

https://www.miataturbo.net/megasquir...e4/#post471856


if he can provide an information about what they are currently doing or how to do it yourself we can certainly help you out.

http://cdn.growassets.net/user_files...pdf?1445897937

Read for yourself. And understand that if it doesn't say you can do it, it means that you can't. The old rules used to say it. That verbiage is not there now. So you can't do it. And there is no such thing as grandfathering in Solo so anyone that has it is not within the rules.

Edit: Nevermind, reading malfunction. It says you can. Must not be awake yet

it's still there:

I have read it many times.

The Megasquirt is considered Reprogramming via hardware and is legal in the stock box with the stock sensors.

The rules from 2005 say.
The rules from 2016 say.

Yeah I contacted him when I wanted one built and never heard anything back. That was 2011. It wasn't cheap as he did lots of stuff to the MS to make it work much like a stock ECU. I can't remember now but I think back then you even had to have working emissions stuff. It seems as if now what you need to have is a working OBD2 port. I don't see anything about other emissions related stuff but I seem to remember a discussion that some thought emissions stuff had to be functional. Never bothered with it as I went to CSP and went standalone.

BTW, is it just me or does that chart say that the OEM 1.6L is making 130 wheel torque at 5000 rpm? That. Can't. Be.

who knows, doesnt even look like a stock miata dyno curve.