Unknown piggy back identification help?
 

https://www.miataturbo.net/attachmen...ine=1399777600

https://www.miataturbo.net/attachmen...ine=1399777600

https://www.miataturbo.net/attachmen...ine=1399777600

https://www.miataturbo.net/attachmen...ine=1399777600

This piggyback setup runs pretty good, but I've had megasquirts in the past and would prefer it.... so I am going to throw this piggyback setup up for sale.

Its pretty neat, I dont know if there is an O2 clamp off hand but there is a boost control circuit that ties into the factory wiring on the pass side of the car?

The piggyback part of plugs into the AFM... It has a vac line going to it (I assume map sensor), and an IAT that goes to a GM sensor in the charge tube.

The dash has a micro headphone jack that runs to the ECU, 2 wires.

never seen anything like it.


looks like it mods the AFM signal to be able to alter fuel. Possible the voodoo? I've actually never seen one.

stock injectors; is there an FMU? what tee's off the FPR in that first shot?


whomever owned that car was smart as hell with that check valve in the pcv line. Must have listened to the Brain.

No FMU. Lots of boost coming out of a stock td04L, 12psi usually.... I went against my better judgement and autocrossed it today without a wideband..... Ran great.

Think that mini headphone jack is a scanner port for the stock ecu?

The real brain melter is the boost controller going into nowhere land into the stock wiring harness... Is there any way people mod these stock ecus?

I'm guessing there's no longer a MAF/VAF on this car, correct?

No maf it appears to be effectively replaced by a map sensor.

I'm going with "Split Second" for $400, Alex.

stock 1.8L injectors. So a slight upgrade for your 1.6L.

no.

How are you even sure you have a boost controller? or better yet: how were WE supposed to know?

most people don't (read 99%), that's why they install silly piggybacks.



Dark, I really suggest you give us no more information, pictures, details to go on, yet continue to ask important questions and abuse the car...

That's not what they looked like.

What I find interesting is that it plugs into the AFM; obviously taking a MAP reading and sending a fake signal back to the ECU.

But then it's still wired back all the way at the ECU...so why even have it connect to the AFM? seems odd; or maybe it was a way to activate the fuel pump since the AFM got removed.

But, I don't ever remember seeing any sort of device like this since 2006.

the split second, which was similar, looked like this:

https://www.miataturbo.net/attachmen...0492-large-jpg

but it was hardwired in only, no AFM connector.

There are many different kinds of Split Seconds.


The other thing i've seen that's somewhat similar to this would be MAPecu or maybe an HKS VPC, but i don't think the VPC box looked like that, and there would be another control box with 6 or 7 knobs depending on generation.


That said, there WAS an application off the shelf for the 1.6 miata for the HKS unit, but i don't know Miatas well enough to tell if we're looking at a 1.6 car, and there was a PNP harness for that application, so i'm not sure why someone would have wired the car as shown in the even it's the HKS unit.

no, I've "tuned" a vpc, wasn't like that. I dont remember anythign being on the AFM connector, just had a map sensor wired back to the knob box.

I need to dig back through the "archives" i have... I believe there was an SDS that looked something like that as well.


OP, basically... rip it out and get a Megasquirt.

yes, that.

Ive built and tuned a few megasquirts... and have a 4g63 ms2/3.0 one on the shelf... I got my adapter harness parts saturday morning...

Woah dawg, I know im just some dumb noob here, but cut me some slack eh?

Autocross is hardly "beating on it" first off.. I make a few 2nd gear pulls a run.. oh well, I said I knew what i was getting into when I did it, and I didnt say I was proud of it.

In terms of "information", I am more than happy to provide more, I am just not sure what you guys would like to know?

I know it has a boost controller because it has an AEM mac valve sitting on the wastegate... and it makes 7psi on wastegate spring alone.

Don't sweat it too much, you've activated the automatic hazing ritual here at MT. :D


It appears from the image of the box plugged into the airflow-sensor connector that removing four screws will gain access to take a few detailed photos of what's inside. Might be informative. I've heard stories about devices which perform this function, and in fact I came up with a scheme for doing it years ago with the Greddy EMU, but I've never actually seen, with my own eyes, a self-contained device to do it.

The 1/8" jack on the center console is also interesting. As Brainey very tersely noted, it's unlikely to be a "scan connector," as the early 1.6 ECUs didn't offer much in the way of external data connectivity. Of course, for all we know there might be some piggyback EEPROM sitting under the lid of that apparently stock ECU. I'd be extremely curious to know where, exactly, those wires go.

That's sketch as hell.

Concealer, the AFM plug, intake manifold, tombstone, recessed letters on the valve cover, and barely legible "B6" on the ECU tell you that it's a 1.6.

I'm guessing the box is sending a standard fake signal to the ECU, or at least just the AIT. Could the box some how be closing the vacuum line to the FPR? I can't imagine a tiny thing like that reacting quickly enough. Although it's just a T fitting.

I'd be interested to see an AFR curve. But I'm guessing you'll get into boost and quickly get out of it if you actually had a wideband.

Disassembly of the magic box did not go well during my first attempt. I would need to completely tear it apart as I see nothing but a metal plate after I pull off the cover.

The headphone jack runs into the factory harness... 2 wires tie in at the top left corner of the ecu if looking directly into the connector.

Boost controller wires tie in at a box (looks like an ignition box on a 2jz) on the pass side wheel well. 2 random cut wires that appear to go nowhere.... I can get colors later.

it was my experience on larger injectors than those brown tops (305cc vs 265), that even at 100%DC, it was barely enough to maintain 13:1 to redline at around 7psi or 170rwhp.

what two wires on the harness do they go to? pin locations and/or color will do...

You can see the headpbone jack wires in the ecu picture.... its the ball of electrical tape at the bottom left of the picture.

I am sorry but I cant get some of the details on this until tonight.

Appears to be 2y and 2z.

Unused in a MS standalone setup, so I'm at a loss.

That's not helpful. We'd like to know which specific wires they are spliced into.

Basically, the setup which you have does not conform to any common system which is known to this community. We can't look at it and say "Oh, that's the such-and-such made by this company, here's how it works." Thus, back-tracing the wiring is about the only way you're going to learn anything about it, presupposing that you even care. If it were my car, I'd just park it in the garage and start ordering parts. MS2 or MS3, a wideband O2 sensor, a set of injectors in the 500cc range, etc.




I also just now noticed that there is a tee in the vacuum line between the manifold and the pressure regulator on the fuel rail. I suspect that on the far side of this hose is a secondary rising-rate fuel pressure regulator:

https://www.miataturbo.net/attachmen...1&d=1399905585

Can we get a picture of that?



I'm also kind of curious as to where the grey wire with the black corrugated sleeve, which comes out of the box into which the AFM connector is plugged, goes.

Could it be 1d and 1b?

The tapped boost ref goes to the magic box and boost gauge.

The extra wire coming out goes to a gm iat in the charge tube.

Considering im a pro tuning shop... I have a ms2 450s and a lc1 here that im going to install in the next few weeks.

Im not all that afraid of it because the previous owner was the furthest thing from a car guy as you could get and he put plenty of hard miles on it with issues.

You're a pro tuning shop?


https://www.miataturbo.net/attachmen...ine=1399906379

I dont operate with much of a profit so I wouldnt be that impressed. I just do it for fun as im a software developer by trade.

These two statements seem to contradict themselves.

Look at this photo:

https://www.miataturbo.net/attachmen...ine=1399907123

From the picture, the headphone jack appears to be wired into right hand side of the larger connector, as you're looking from the front of it. Which would be 2y and 2z.

Yeah, it sure looks to be like it lands near the INJ wires (the two fat yellow ones), which would put it in that vicinity.

2W and 2X are the idle solenoid and purge valve, respectively. 2Z is a tie-line to the transmission computer on vehicles with automatics, and is unused on the M/T cars. 2Y is not indicated as ever having a wire in it on any 1.6 Miata. (I'm assuming that this is not a California-spec '93 car.)

None of that makes any sense.

I asked for the same, but I think it's going to the box on the AFM after thinking for a second.

It took me the re-quoting of that picture to catch that gem.

oh i c wut u did thar!


WELL PLAYED, GOOD SIR!

It's the little things that make me love this place.

Yeah, i completely lied when I said top left... I worked on my honda megasquirt a bit this weekend and I became a bit confused when I just now thought about it.

I'm beginning to think there is something living inside this ECU.

Yeah, open up the ECU box and see if someone's replaced it with a Link or similar.

--Ian

https://www.miataturbo.net/attachmen...ine=1399950494

wat

I cant find the crank/cam inputs....

Ahahahhahahaha you have a MegaSquirt.

OHHHHHHHHHHHHHHHHHHHHHHHHH I recognize it now.

You bought your miata from someone named Ananth or something like that?

I built that MS for him in 2007 so he could cheat in autocross. The AFM connector box thing is just the map sensor; it used to be hidden in his gutted AFM.


Surprised it wasn't disclosed that it was running MS.

Ah yes the old "stock ECU case" clause.

but he cheated with the map sensor...that actually broke the rules, but he didn't care.

Look harder. They're there; their input circuit is plainly visible in the circuit board image you posted.

We also now have an answer to the mystery of the 1/8" TRS jack on the dashboard. It's an RS-232 port for programming the ECU. See this pad:

https://www.miataturbo.net/attachmen...1&d=1399984676

As the owner of a pro tuning shop, you are no doubt aware that in a standard Megasquirt, there would be a DB-9F connector on that pad. In this build, that pad has been wired out externally. You'll need to trace the wiring through to the jack to determine the correct pinout to construct a mating connector- pins 2 (blu/wht) and 3 (grn/wht), in particular, are the Tx and Rx lines, and you need to know which one is tip and which is ring.




Haha- my first thought as well -"Ok, I KNOW I've seen that ECU before!"

As I pro tuner, I read Megasquirt on the board and knew it was a LINK of sorts ;)

Well duh the phono jack is a tuning port... I knew that the second I opened it..

Im not seeing the opto isolators or a vr on the board? What am I missing there because all the ms I have built just use the standard opto or vr circuts.

The guy I bought this car from had basically no clue what a turbo was let alone a megasquirt was.

Also. Im going to replace the phono with an rj45 the same way I modded my lc1.

Oh. Remember what code base he was on? I will probably end up swapping over to ms extra if I can or need to. I have alot more experience with extra and I want fireball antilag for the fun of it.

it's running spark as a complete standalone, therefore it must be on extra.

more than likely it's on 10_hr; a simple connect with TS would confirm this.


enjoy blowing up the car.

Wait what? Blowing up this car? What do you mean?

So I take it im still just blind and cant see the crank trigger components?

He's saying you're asking questions that would be extremely easy to answer for yourself if you knew how to hook a laptop to it.

So sue me for making conversation. .. im at work and I wanted to know if I should try to connect with ts or mt... my tuning laptop with both recently crashed so ill just put ts back on my new machine.

They are on the bottom of the board.

The crank signal goes in the opto circuit (U3, not visible) and the cam signal goes directly to JS10 with a 470ohm pull up to 5v. It's running the 4G63 trigger wheel decoder

why do you need to see them?

There are a number of different ways to handle the crank and cam inputs on a Megasquirt.

My own preference is to use either a MAX9926 chip or a circuit based on a dual-comparator such as a TL082 or LM393, derived from work done several years ago by AbeFM, JasonC and myself. Such typologies afford the best opportunities for noise filtration, proper implementation of adjustable hysteresis, etc.


Historically, it has been common within the MS1 / 4G63 community to use the stock opto circuit (with a pullup) to handle the CKP signal, and to apply the CMP signal, with a pullup but without any isolation, to pin 11 of the CPU. Again, this is not my preferred method, but it is the one historically practiced by the community and endorsed by DIYAutoTune: https://www.diyautotune.com/tech_art...azda_miata.htm

So that's what you've got here. It's an ancient design which lacks proper isolation and input filtration, but it seems to work for about 90% of users.

Thanks joe. Im not the best when it comes to inputs just yet so new concepts like that are helpful when explained.

I spent 2 days trying to get the stock 3.0 vr circut to read my honda missing tooth distributor setup without any luck... so any information I find on the subject helps better my understanding. I will be setting it up with an aem epm trigger now to delete the distributor and go cop.... my current plan is to use stock 3.0 opto input and another add on using a similar opto isolator to read the 1x wheel... are you suggesting I can use the output from the 1x wheel unfiltered?

Yes, that much is obvious. :giggle:


1: You don't need an AEM EPM trigger (or any other aftermarket device) to go COP.

2: Your car does not have a distributor. It has two ignition coils wired in a wasted-spark configuration. EDIT: Oh, wait, are you talking about the Honda here?


I'm not exactly sure what you mean by "1x wheel."

And, as someone who has spent a lot of time working with input circuits on the MS in a Miata context, don't waste your time duplicating the stock opto circuit for a second input. If you're gonna build a non-stock input circuit, do it right: https://www.miataturbo.net/megasquir...ircuits-25789/ EDIT: I assume we shafted back to talking about the Mazda again.

Sorry I wasnt clear enough but I totally switched gears to talk about my honda.... I have a megasquirted miata already lololol. :) ")

Thanks for the help on this though I really do appreciate it. The reason for the distributor delete was mostly due to the fact I cant make it stop leaking oil :(

The aem epm had a 24x and a 1x wheel. 4 wires. 12v+, ground, 1x out and 24x out.

Nope I understand the mazda vaugely enough that I know what I want to research to understand it better... I plan on finishing up the cop honda ms2 build here next week... I still have a few relay outputs to build as well as the ls1 coil plug wires and logic outputs.

I gotcha.

I'd remove the distributor from a B engine just on general principle- they offend my sense of style.

And yeah, that AEM unit will work fine on any MS using the generic toothed-wheel decoder setup page, for any combination of batch / sequential injection or ignition you can come up with. 24T is kind of a weird one, but the Wheel Decoder Spreadsheet will give you everything you need, once you determine the angular alignment of CMP relative to the crankshaft.

Cool. I already mocked up the ideal 1x location and wrote down the angles. Running some 1200cc injectors so im excited about sequential.

Looks like ms1 does not support fireball antilag mode.

Its been a long time since I've been on the forum...Hi old friends!
I know this is an old thread but I stumbled across it with some random browsing :jerkit: and felt compelled to reply.

For the record, I never cheated in auto-x:fawk:. I came up with the wiring scheme, and took Brain's help in wiring this ECU originally to be legal in the old STS class (I think). I quickly realized that getting around the "stock AFM rule" was going to be very difficult if not impossible with my electronics skills at the time. So I turbo'd it and had a hell of a good time after that in one of the prepared classes (I forget which exactly, maybe AMT). Won several events and legitimately beat the crap out of much more expensive and well prepared STi's, EVOs, Corvettes and one time, even an Elise.

It looks like this car changed a few hands after I sold it in 2011 or so, but I'm happy to see that it's still running well after all these years. It figures, I spent a shitload of time tuning it and tried to account for every possible scenario with the fuel and idle control maps, with the exception of altitude (not many hills in MI).

Oh and just as hindsight, my total budget for the turbo project was $1k and I came out slightly behind, at $813.89 for the turbo parts and ~400 for the ECU. :)

Anyway, good to see you all again. Back to my cave. Ciao!

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