RomRaider

Sure, I'll put the 201X and 06STi on my list of stuff to check out and let you know how it goes, should have some time in the next couple of weeks.

There are some benefits with blending.

When MAF is involved the fuel calculation algorithm is much more robust against intake\exhaust\valve timing modifications. Ignition timing may also be more robust provided being based on the engine load and RPM (not being intake pressure\RPM dependant). Hardware minded guys love this..

Moreover under boost the pair of parameters (intake pressure and engine) is insufficient for air flow calculations. Something else is needed due to unknown exhaust back pressure and\or turbine efficiency. MAF blending seems to be the most evident solution.

I am not against SD approach. Moreover I drove my NA car in "pure SD" closed loop mode for more than a couple of years. No problem with idle, cruise, full open throttle. Throttle cranking was not wonderful. The tip in enrichment algorithms looks being extremely artificial. Intake pressure oscillations made things not as good.

After that I added a throttle position sensor and used AlphaN SD blending. Things became much better. Tip in enrichment became transparent and straightforward (still being engine load\engine speed dependant and temperature compensated).
Currently I am driving pure AlphaN closed loop (formarly injector latency and flow capacity are realtime corrected). It's great! Sure, the TPS could not be the only sensor at a boosted engine. Unfortunately TPS+MAP is insufficient as well. Something else should be measured - air flow\exhaust back pressure\turbine speed\etc.. Otherwise loopback control should compensate unknowns. The last makes transients much longer.

Update: about everything is ready to go on the A8DH201X, should have a test rom setup to log VE but still running on MAF to verify the code sometime this weekend, of which I'll post some IDA screens before flashing.

I also cracked open an 06 STi A2ZJE11J, found all the maf conversion, maf diagnostic/cel, and map conversion routines and references. Just have to find the other parameters and I can start on the coding. I hope to have something to test by spring.

Cool stuff! I hope to free up time to help sometime soon

Freon, can you elaborate on how you're assembling the code? I've been using the HEW gui to build .asm files, and it works, but spits out a bunch of garbage with it, so it takes a few more steps to put it in a rom and check it. I finally got the command line compiler working, but it's still throwing in other stuff before and after, using commands: "sh-elf-as assembly.s -o assembly.o" or "sh-elf-gcc -c assembly.s -m2e" Is this just the nature of the beast?

Also, any advice on choosing the best ram location for the new parameters?

Any chance of this being available for JDM ECUs in the near (or distant) future?

Any updates on the SD release for an 05 STI?

I've finished most of the work for the 06 STi, but I need to recover some ecu's before I can move forward and have a viable patch, hopefully that will happen this month.

If Freon is too busy to finish the 05 I'd be glad to take a look at it.

I really hope Freon or others can get the time to put in the compensation tables to combat the rich shift conditions.

May have missed it but anything on the 08 STi or WRX yet?

Ditto

I kind of ignored this thread for a long time, but I have taken a renewed interest after seeing how poorly MAF-based fueling is working for my Legacy after switching to a FMIC and the standard "stage 2" exhaust upgrades. It's ridiculous. I want to put in a bigger turbo this summer (probably an ATP 3076) but I suspect that the higher pressures will just screw up my AFR's even more. So I just read the whole thread. Got excited at the mention of possible ports to the Legacy, got depressed when I reach about the shift issues...

...and had an idea.




Trusting boost error as an input means making some assumptions about boost targets and how the car reaches them... but I think those assumptions change depending on which gear you're pulling in. That's certainly the case for my car, and I've also noticed it in graphs MickeyD has posted, showing boost response in different gears. It also seems like delta-MAP would be misleading in cars mine where the boost tapers toward redline. I don't think that means backpressure is decreasing.

Have you considered using throttle history to approximate backpressure? What I mean is:

Set aside a memory location to store a low-pass-filtered copy of the throttle plate angle. With each iteration of the code, set that filtered value as follows:

throttle_delta = current_value - filtered_value
filtered_value = filtered_value + (0.5 * throttle_delta)

The value of the constant (0.5) could be adjusted to make the filtered value converge on the current value quickly or slowly.

If the filtered value is less than the current value, you know the driver is adding throttle, so you assume that backpressure is low (and VE is increased). If the filtered value is higher than the current throttle, you can assume that the driver is lifting throttle, so backpressure is probably high (VE is decreased). So you can apply a compensation like:

VE = VE + (compensation_factor * throttle_delta)

With luck, a scalar will suffice for the compensation factor, but it might help to look it up from from a 2D table indexed by throttle_delta.

One more thing: while I'm a long ways from coding on our ECUs, I am learning to read the code and would be happy to do code reviews. That would give me more good examples of code to learn from, and would (I hope) help prevent bugs from finding their way into anyone's ECU.

Also I'd like to think that by making this more of a social endeavor and less of a work-alone-at-night-by-candlelight thing, people who can write code will be more inclined to do so.

If this offer still stands, I'd like to take you up on it for A2WC510N. I'm really curious as to whether this will fix the problems I've been having keeping my AFR under control.

If it does, I'll spend some time logging and playing with Excel to see if I can find a good strategy to fix the problems people have reported with shifting. If you leave some space at the end of the SD routine, I might even take a shot at implementing whatever compensation looks most promising.

I have an 06 bajaT, im looking to do the perrin GT3071r .63 A/R and the sig, series fmic along with 850cc side feed injectors and walbro FP. The kit doesn't have any way to use the stock MAF sensor.. I either have to go UTEC and do speed density, or blow thru boost... unless there is a way to get SD for my ecu.. I have no idea how it works or anything, I was reading the posts and everything but its wayyyyy over my head haha. My image is A2WF100K. Is there a way i would be able to get SD for that?