Does your hardware support realtime tuning?

Exactly the same as a PowerFC with a datalogit -- you can edit any value on the fly. Of course, you have to hit the "write" button to do so.

Have you found the boost control system?

Twin-scroll? Haven't yet looked. Boost cut and boost sensor clipping has been found.

Have you found the idle speed and idle mixture feedback systems?

I understand a good portion of the BAC operation and the RPM ranges, as well as it's duty cyle and table. Haven't looked for much else.

Have you found the knock control system?

Hadn't thought to look for it until now.

Have you found the injection timing control?

This is part of what I'm doing now -- it's rather a pain to do without a vehicle and having to try to simulate on the bench. I need to create a rig to spin the CAS for me. Time to get my DX7 out and use my brushless RC plane motor.

Have you found the tip-in fuel control?

I believe so. I've got that section flagged, but it's one of those things I need to test and evaluate with more sensors than what I've got sitting on my bench.

Have you found the cranking fuel and warmup enrichment control?

Yes.

Have you found the closed/open loop switchpoint control under acceleration?

I believe so -- at least I have a fairly good idea of how the process works.

Have you been able to find controls for any of the switched outputs (emissions solenoids etc)?


What sample rates have you observed when logging?

About 10x the rate of the PowerFC. I use the exact same communications protocol as the PFC, except I'm transferring a whole lot less data at a much higher speed. In theory, I can get about 450 samples per second of all the typical datalogging information. I think the only time I set a counter on it, I was around 350 or so.


Have you found the airflow meter voltage to airflow units transfer function (would be MAF scaling on a real MAF car)?

I know where this function is in the code, but I haven't spent much time decoding it.

Have you found the boost sensor scaling?

With regard to how it applies to the fuel calculation or something else?

 

While I am no longer in the RX-7 game (sold 4 months ago) I would LOVE to see how the stock computer runs the BAC. I spent hours poking and prodding with my dinosaur E6k, which was very limited on controlling the BAC. Basically I picked a pulse width, and a hot/cold temperature changeover. There wasn't much to it, which is why I was always curious how mazda did it so perfectly. Is there a simple values table you could post up? It's strictly curiosity for me at this point.

Also I'd like to see what mazda does when cranking/starting with fuel

Thanks, and good work! I read everything, even though it's all hieroglyphics to me.

 

Thanks for answering my questions. Here are responses:

On an S4 it would just be a twin-scroll changeover, but we do have documentation from the service manual for that.

I am talking about on the S5: is it a target boost algorithm with baseline duty cycle + feedback gain settings? Or is it a target load or target airflow based system? Does it have air temperature or knocking correction?

So an S4 is a dumb external box but for the s5 I believe it has some of the basics of a modern knock control system. There should be a filtering algorithm, maybe a background noise learning algorithm, some kind of threshold to judge a knock event (and maybe to judge its severity), and some spark retard authority. Then there should be some spark retard decay logic at the very least. There may be a knock retard learning table. I'm not sure how sophisticated it is, but I'm familiar with knock control on other OEM systems.
We have diagrams from the service manual for this. I'm just curious if it's end-of-injection calculation or start-of-injection calculation. Being a port injected rotary you don't have open vs closed valve injection type of deal like a PFI piston engine.

Yeah ideally you need a hardware in the loop setup and rapid prototyping setup. They cost big dollars.

The question is whether the tip-in fuel adds pulsewidth to the initial injection event (sychronous event) or includes additional injection events (asychronous tip-in). Then what are the thresholds that govern that. I highly doubt there is a fuel wall-film model like a modern PFI piston engine. It's too old.

[Awesome, that's good to hear.

That's important when changing around the intake system.

I was wondering if we can switch to a higher range MAP sensor (3 bar or whatever) by changing the sensor scaling.

 

I have almost exclusively looked at only the S4. However, I have seen that the S5 boost controller is a duty cycle table with a corresponding target boost table.

Swapping to a 3bar should be fairly easy to accomplish.

 

Would you be willing to provide hex addresses, map sizes, physical units and scaling, etc (basically ROM definitions like you'd see on OpenECU or TunerPro)?

 

Of course. I was waiting to post that up until I was further along with trying to map everything out.

 

Stumbled across this thread and just... whoooaa...

This is an awesome idea. Hope to see this happen.

 

Still on the road, so I've been keeping myself occupied going through the disassembly and labeling as much as I can.

 

Keep us posted and let us know if there is something someone else can do in the mean time.

 

I'm back at it. Still waiting for boards to show up, then I can get these things on a few test vehicles. I may need to find some more guinea pigs.

In the meantime, I've been working on a few features/basic things and requests:

• Idle Speed Control
• AFM Removal
• In-Place Firmware Updates
• In-Car Initial Set
• Flood Clear
• Programmable Outputs

 

Thought on flood clear, check rpm versus tps. If rpm less than 600 and tps is at wot then no injector pulse injectors stay off till key cycle. Simple if then and then logic, but pending on the lookups might not be so simple.

 

OINK OINK. if that is what the guinea pig says

 

Not sure what your test setup is/needs, but I do have a spare engine & timing harness I would be willing to borrow/donate. It's a bit hacked up, but I've taken the liberty of labeling any loose wires. It has a CAS and all the sensors (minus the injector resistor pack) Otherwise I have a spare ECU I'd be willing to try this on!

 

Yep, pretty much. Just had to add it in.

What series/ecu/aspiration/fuel setup are you using? Boards come in sets of three, so ideally it'd be useful to have three piggies.

My current test setup absolutely sucks. I had a hacked off harness end I was planning on using, but I can't track it down anymore, so I'm currently stuck having to try to wire in things one at a time while I'm testing. I do have a CAS already though just for this task.

On that note.... I'm in serious need of sensor scaling values. I don't have any of the sensors on hand (air temp/water temp).

If someone wouldn't mind, I could use some voltage -> temperature readings from each sensor. The FSM gives some "general" readings, but not enough to interpolate anything from.

 

Count me in for Guinea pig #2? S4, T2, Currently stock injectors, fmic, hybrid turbo, walbro 255, ported motor

I'll see if I can borrow a power supply from work and get some readings for you. To be clear you need Voltage vs Temperature readings on just the air and water temp sensors?
If memory serves correctly, its a 5V signal on each wire?
If it would help, I would still offer up the harness for you.

 

Yeah, it's a 5V source drained to ground through the sensors. The ECU has a few values, but it's not a lot to work with. It would be ideal to use an ECU to power the sensors.

 

True,
I've seen a voltage drop across my signal wires of about 0.2V - 0.4V. I can use my spare ECU to power it.

 

I can back probe on car and give readings if you say which ones you would like. If your still looking for a 3rd tester and want an additional s4 t2 large street port, stock top mount, stock injectors ported wastegate racing beat turbo back exhaust and a 255 walboro lmk. I will more then gladly help in this project

 

The S4 TII is the ECU I've worked with the most. There are a few major things I need to get out of the way before we can get testing under the way -- namely, the in-place ROM upgrades, so that we don't have to play magical EPROM's in the mail every time a change is needed.

If you have an accurate way of measuring the coolant temperature/air temperature, you can backprobe the sensors and record the temp/V.

I'm pretty close on coolant, but would like to verify my "findings."

 

Which of the two coolant temp sensors are you after? The 2 pin on the back of the water pump housing or the single pin on the thermostat housing. I am assuming the iat you want is post intercooler and not in the VAF correct? Let me know which ones your after and I will work on getting the measurements.

 

The water thermosensor (back of waterpump). Both air temp's would be nice (since I can monitor both). I found my harness pigtail, so that might help my testing abilities a bit.

 

If you guys do a real time monitor of the sensors, I would probe them from the ECU side since that will take into account sensor reading variations caused by wiring in the car.

I would take some readings for you sonicrat, but I currently have bacterial bronchitis.

 

I get that crap at least once a year... sucks. I'll be heading back home (again) today, and I'll try to get with some of you who wanted to be testers. Once I get the first batch of boards in and verify they're good to go, we can get some more made up for the next round of testers.

Just shoot me a PM if you've got a S4 TII (or perhaps a S4 NA if you don't mind waiting a tiny while) and were wanting in on the "testing."

 

I can test for you when you get to S5 NA. I have stock everything except for a mild street port.

 

the JDM shop manuals have the sensor voltage curves, i can scan a few in if you like. we even have the AFM voltage/airflow curves