Corruption

I'm sitting here scratching my head wondering how to wire this into the ECU. If I could get any help how to wire this, that'd be great

Miata.SharK

DIY version:
you have to prepare a boomslang

Step 0: https://www.miataturbo.net/useful-saved-posts-8/
You can find a lot of material here -- there is a guide for EMB, but honestly I don't like the idea of soldering OEM ECU!

Step 1: download official manuals from greddy.com websites. There's a section related to the wiring configuration.
Summarizing: EMB will require:
- Ignition
- Injection
- RPM signal
- AFM signal (flap for NA, hotwire for NB/FL -- if hotwire remember to add 1k ohm resistance!)
- TPS
not strictly required for having your car working
- on the option/boost port you will wire MAP (GM, i.e.)
- on MAF 2 you could plug wideband input (and log using emanage tools)

Step 2: Find where your signals comes from
https://www.miataturbo.net/useful-saved-posts-8/90-2002-wiring-diagrams-10738/

Not-fun version:
http://www.boomslang.us/ or similar

Corruption

Thanks man, runs great now

sturovo

The EMB vtec +12v output can also be used to control o2 clamp/ TPS autotune type circuits.

Corruption

Now that it's running well, I'm having a bit of a problem with the timing. The gentlemen I worked with regap'd my plugs, but I don't think he set the timing to 8. Is there an easy way to check/set the timing? I also have a problem where when idling, it'll go up to 1-2k and slowly droop back down then back up. Sometimes it'll sit pretty at 850, but otherwise it has a mind of it's own. It also gets bogged down at high revs sometimes. I still need a proper tune, got the emanage with the kit already set for it, but I was wondering if there's anything I can do to make it better for now.

Sentic

iTrader: (1)

Get a wideband afr, you need to know what is happening.

Miata.SharK

+1

Get also a det-can for understanding if your engine is detonating or not.

Keep in mind that you start from OEM timing and you add/subtract advance.
For instance, let's imagine that the OEM advance is (for a certain RPM & airflow) 16 deg
you write "-6" => 16 -6 = 10 deg advance => you are retarding
you write "+6" => 16 +6 = 22 deg advance => you are advancing

For the idle, I stongly suggest to play with anti stall MAP in order to clamp a AFM voltage


@sturovo, interesting, very interesting diagram. Can you give us additional details for making a O2 clamp using VTEC map?

Corruption

I fixed the timing/idle problem with a new coil pack (mine was ------- GONE) and played with the timing and idle screw. Hits boost like a ----------ER, IT'S SO FAST. I'm getting it properly tuned on Saturday, so excited to see what's it making now and what it WILL make.

sturovo

The clamp circuit is a relay and a couple of variable resistors.


The EMB vtec out put can be set with a jumper (jp3 2-3) and the vtec map (example) reflects when you want the clamp to be active.


(The autotune part uses an error correction EMB additional injection map driven by the o2 sensor connected to the TPS input.)

MaD

Thank you sturovo!

Can you tell us how to regulate the variable resistors?

sturovo

Initially when wiring up the circuit the voltages are set and typically do not need further adjustment.

The way I set the voltage is to start the car and turn the screws on the variable resistors until the desired voltage is achieved measuring with a multimeter to ground. (To make setting the o2 clamp value easier I added a test point to a spare terminal which is not shown on the diagram.)

Once set, the voltages are fairly consistent each time the car is run as the system voltage doesn't change that much. (You can record the TPS signal on EMB and compare the setting on different runs to verify that circuit gives consistent clamp voltages.)

The 0.34 volt signal for the o2 clamp corresponds to around 12.5 AFR cruise on my car. (Lower clamp voltage gives richer AFR, higher gives leaner AFR.)

If using autotune the TPS clamp voltage should be set so that the additional fuel injection map does not react when the o2 clamp is not active. In my case the 1.02 volt signal corresponds to to around 57% of TPS scale ((1.8-0)/1.02*100). (For wideband autotune these figures would be different.)

Even if not using autotune it is a good idea IMO to bring it to EMB TPS as it enables boost AFR data logging.

In my experience Autotune works well with larger than stock injectors and lower (7 psi) boost levels. The o2 clamp voltage sets a decent 12.5 AFR to start and the TPS map adds more fuel as the o2 signal leans out and is able to react in time to hold good AFRs.

At higher boost autotune struggles to keep up with rapidly changing conditions because of the nature of the feed back loop. On a gradual pull at higher boost autotune can provide real good information for mapping. (I was able to quickly build 90% of my higher boost map in this way.)

The way I have my autotune set up is that it corrects by adding fuel on lean o2 signal. I may try it the other way, subtracting fuel on rich signal.

MaD

Good job Sturovo, and many thanks for the infos!

At the moment I'm using the VTEC output as Wideband input for logging, so I'm wondering if on EMB is possible to drive relays with an injection output, like EMU... (EG channel 7/A)
Anybody knows if it is?

Thanks in advance!