RomRaider

If you are already running an un-patched A2WC522N ROM, and you'd like to have speed-density fueling, and/or launch control and flat-foot-shifting, then run RomPatch-v5.exe with the attached 522N-to-540E patch.

If you are running A2WC522N with my previous LC-and-FFS-only patch (no speed-density), see the next post for instructions for removing the old patch. You must remove the old patch before you can apply the new patch.

Click here for RomPatch.exe

Applying the patch should look like this:



If you see anything other than what I quoted above, stop.
Something is wrong.
Do not attempt to make it work.
Paste the error messages into your reply and I'll take a look.

But, if the patch was applied successfully...

Copy the attached A2WC540E.xml file into EcuFlash's "RomMetadata\Subaru\Legacy GT" directory.

Then open the patch ROM in EcuFlash and verify that the SD, LC, and FFS tables show up.

The open the attached logger.sd.xml.txt file in Notepad, and copy the contents into your logger.xml file. The new <ecuparam> elements should be inserted right above the last </ecuparams> element.

The LC and FFS thresholds are reasonable starting points, but don't hesitate to adjust them to suit your mods and your preferences. I'm using 7100/7200 for redline since that's what I found in the ROM for an STI that has a nearly-identical longblock. I'm really not sure what's best for FFS... I've only just started messing with this stuff so I'm not the best person to ask.

Note that the volumetric efficiency table is not properly tuned. It comes directly from Freon's original speed-density patch. You'll want to run with speed-density disabled (so the ECU uses the MAF sensor) while you adjust the VE table to get the speed-density MAF values to match your actual MAF values. Only enable speed-density after tuning the VE table.

As noted above, if you're running A2WC522N, and you did not already apply my LC/FFS (no SD) patch, then you can apply my new patch to your ROM to get SD, LC, and FFS. The post above has all of the details.

* If you're running A2WC522N, and you did apply my LC/FFS (no SD) patch, then you will need to remove the old patch before you can apply the new patch. In order to apply the new patch, you'll need to remove the old patch first, and for that you need a copy of the old patch file, and the old (v3) version of RomPatch. Run this command to remove the old patch:



* If you're running A2WC510N, A2WC511N, A2WC521N, etc, then you can copy your tables to a 522N ROM and flash it. I had A2WC510N on my ECU when I bought the car, and the switch to 522 took some time, but it's not particularly hard. There's just a lot of tables to copy over. After taking that step, see the next post for instructions on applying the patch to your new 522N ROM.

* If you have a 2005 Outback XT with a manual transmission and a A2WC522S, there's a very good chance that you can simply flash a 522N ROM as described above, and proceed with patching. The 522N and 522S ROMs are almost exactly identical - as far as I can tell, they do not differ in any way that would affect this patch. However I have not tried that myself yet so I cannot promise anything.

How does the SD patch work?

The short answer is that it uses manifold pressure, air temperature, and RPM, plus some arithmetic, to determine how much air is flowing into your motor. Whereas the stock setup uses the voltage from a mass air flow (MAF) sensor to determine the same thing. With the MAF sensor, you have to adjust the MAF scaling to tell the ECU how much air is flowing into the motor for a given MAF voltage. With the speed-density patch, you have to adjust a volumetric efficiency table to tell the ECU how much air is flowing into the motor for a given RPM and manifold pressure.

The long answer is this thread: viewtopic.php?f=37&t=2947

What if I don't want speed-density? I just want launch control and flat-foot shifting!

By default, this ROM actually still uses the MAF sensor. It calculates airflow using speed-density math, and you can log the calculated value, but it will actually continue to use the MAF sensor. It will only start using speed-density if you enable that feature (there's a simple table for that).

Is speed-density dangerous for my car?

Speed-density won't hurt anything, if you tune it properly. It's not any more or less dangerous than MAF-based fueling.

How does the LC/FFS patch work?

I have replaced the factory rev limit detection function with my own. My version sets the rev limit to one of three levels, depending on the clutch switch and vehicle speed:

Normal redline rev limiter: If the clutch is not pressed, you get the same rev limiter as usual.

Launch control rev limiter: If the clutch is pressed, and you're stopped, you get the launch control rev limiter. This is usually set to 3500-5500 RPM. The idea is that you can give it full throttle while you wait for the "go" signal, so that you maintain a good RPM for launching, yet you build boost so you launch hard.

Flat foot shifting rev limiter: If the clutch is pressed, and you're moving faster than the "flat foot shifting threshold," you get the flat foot shifting rev limiter. This is typically a bit higher than the launch control rev limiter. The idea here is that you can hold the gas pedal to the floor while you shift, relying on the FFS rev limiter to keep the engine speed reasonable. Since the throttle never closes, you don't vent all of your boost out the bypass valve (or blow-off valve if you're so inclined), so you enter the next gear with more boost and thus more torque than you would have otherwise.

The actual rev limit itself is still fuel cut, just like the factory redline limiter. All my code does is still the ECU to cut fuel at lower RPM than before, under the conditions described above.

The factory rev limit won't resume fuel until boost drops below the level specified in the "Rev Limit Fuel Resume (Boost)" table. That feature was removed. The value is still present in the ROM, but the ECU no longer refers to it. I figure that anyone who is using this patch would probably just raise that it an unrealistically high value anyway.

If you really want to know how it works, including source code, refer to this thread:
viewtopic.php?f=25&t=7680

Are launch control or flat-foot shifting dangerous for my car?

Hell yes. I haven't broken anything yet, but I bought a pair of spare rear axles a few weeks ago, just in case. There's a video on youtube showing a guy with an Impreza breaking an axle while launching without a launch-control rev limiter, and launch control has the potential to put considerably more stress on the axles. (And I suspect that Impreza axles are stronger than LGT axles, though I'm not certain of that.)

Some say that FFS can actually reduce driveline shock if you tune it right and shift consistently, but nobody is likely claim that LC is anything but abusive to your drivetrain. And if you don't tune FFS quite right, I'm sure it will be harder on your axles (and diffs, and transmission, etc, etc) than letting up on the throttle like a normal person would while shifting.

When you launch with LC, you launch harder than without it. Since the intake manifold will be in boost, you're going to make a lot more torque than usual. If you're drag racing, this may help you achieve faster starts (honestly, I'm not certain it's faster than slipping the clutch or using wheelspin, but it's worth a try and it's fun to experiment). If you're not drag racing, this is probably not a good idea.

What if I don't want launch control or flat-foot shifting? I just want speed-density!

Just set the cut/resume thresholds for LC and FFS to the same values that you use for your redline rev limiter. You can use this approach disable LC and retain FFS, or vice-versa.

Awesome! I'm already running Tiny's, but keen to have a look. I'm sure you don't mind if I have a look at the disassembly?

If I have some time, I can possibly port this for some of the later Rom that I've been working on (08 / 09 EDM, USDM and 2010 SE) if that's alright with you.

I love this place! Can't wait for Merp new project...

Yes, please.... I'd be happy to have help porting this to other ROMs. I've been meaning to add a GPL header to all of the source files in the other thread, but I keep forgetting...

The EcuFlash definitions that were posted here the first time were incorrect. I've updated the XML file with the correct version.

If you've applied the patch to your ROM using RomPatch.exe, all you need to do is download the updated XML file.

I've also updated the ROM in the first post. I've you've already copied your tune into it, you should copy the tables in the "Fueling - Load Change Compensation" section from this new ROM into the one you have. The previous version tended to stumble when revving up from idle, and this version fixes that. Two or three of the tables in that section were returned to stock and a couple others were modified instead. There are no other changes to the ROM.

Works great!

smoked my clutch.. haha

FFS is pretty cool, too.

Awesome, I'm glad to hear you're having fun with it.

I just noticed that my laptop's EcuFlash crashes when I try to edit the LC/FFS tables with the EcuFlash definition above. It works on my desktop, and it works on my CarPC, but still, something ain't right with the definition. But it's late so I'll dig into this more tomorrow or the next day.

http://www.facebook.com/video/video.php?v=129681487142969
In Action

I've added the speed-density patch.
You'll need to remove the old LC/FFS patch to apply the new SD/LC/FFS patch.

I used your project13 and RomPatch to add SD to me OBXT ROM and it simulated fine so I flash my car with it. The car started and the LC revs held were I set it. So now for some driving...

Trying to open a patched ROM crashes ECUFlash. Using the 1.43.3150 beta...
Looked at the def xml but didn't see anything obvious that would cause it to crash

I'm using 1.42.2595 on my desktop, which is where I do all of my development.
I'm not sure which version is on my CarPC, but I'll check.

It's also possible that what really matters is the ECU definitions, make sure you have the most recent ones:
viewtopic.php?f=8&t=3808

Looks like you were right about the defs. Swapped the defs in and ecuflash now opens with no problems. I can't remember when I last checked my defs