Tuning the M1.8 ecu (pre-95 960), an experiment.

Bah, just ordered the OTP DVD for the 900/90 series cars. There's a few more motronic documents there, so I'll hopefully be able to satisfy my urges for answers.

Been plugging away at this, even though I can't test any of it yet. I think I've found the rev limiter(s), although it's only a guess based on the rev limit values in the M4.3 and M4.4 whiteblock files. I have found a 6200 rpm value (soft limit) and a 6400 rpm value (hard limit). I am very much a layman when it comes to this stuff, so I expect to be wrong way more than I am right...but eventually the answers reveal themselves. Can't wait to test!

Unless someone with an ostrich and an M1.8 car wants to test them for me....

I'll see if I can do some testing on the bench. 6200 and 6400 seems a bit low. I believe I have reached higher rpm now and then.
The 6990 and 7200 checks would be pretty pointless if the engine never reaches those numbers.
I'll have to lower them to check, my desk ECU doesn't understand my PC signal above 5990.

According to my experiences 6200 and 6400rpm seem correct. Stock engines won't rev any higher.

rkam said:

I'll see if I can do some testing on the bench. 6200 and 6400 seems a bit low. I believe I have reached higher rpm now and then.
The 6990 and 7200 checks would be pretty pointless if the engine never reaches those numbers.
I'll have to lower them to check, my desk ECU doesn't understand my PC signal above 5990.

Click to expand...

According to the M4.4 tuning stuff, 6200/6410 seems bang on. The tach may be visually inaccurate, or perhaps on the autos the limiter is different due to the shifts being handled by the TCM. Hitting the limiter in 4th/lockup would put you probably over the speed cut.

Lankku said:

According to my experiences 6200 and 6400rpm seem correct. Stock engines won't rev any higher.

Click to expand...

I really wish I had a running 960 to test on, lol.

Ignition advance is reduced by 7.5 degrees if rpm is above the 6990 limit.

Any progress?

Ill be swapping an M1.8 B6304 into a 240 with auto attached this weekend and have a spare ostrich to play with!

Progress is slow. I had a laptop failure and panicked for a few days, but managed to recover all the data. I have an XDF with all the maps, and what I THINK they may do, but I don't have an ostrich or a running 960 to data trace the maps while running to confirm. If anyone wants to help by tracing the maps while running, hit me up via PM and I'll send it your way .

Ive got 2 Ostriches!
Finally got the car running this morning, I had an accident at the shop and havnt been able to tinker with the car for the last 3 weeks as ive been on crutches
How can I help?
Ive swapped in a 95 B6304 & trans from an AUS delivered 960, No EGR & deleted everything but trans and engine wiring.
I should have it all plumbed up properly in the next 2 weeks and can run all the tracing you need.

https://www.youtube.com/watch?v=pyBb9gIksB4

Cool, I'll hook you up with what I have .
Email incoming tonight.

Well, I hate to be yet another no-go with M1.8 tuning...but I'm officially ending it. I've decided to just modify and use the MS2 from my B21+T to run the B6304. I'm more than willing to turn over the XDF and any files to anyone who wants to continue on with the project.

As for the speed sensor, Ive had the M1.8 B6304 running in my car for the past 2 months and I can share these notes so far:

I have not hooked up the speed sensor OR the in cabin gear selector module, therefore the TCM will revert to "Emergency mode" which consists of 100% line pressure shifts at all time (Really not that harsh at all) and NO automatic lockup converter engagement. The transmission uses its own gear selector sensor and speed sensor to prevent 1st gear engagement at too high vehicle speed.

The transmission will shift perfectly fine without the VSS or gear selector sensor (In cab - NOT on box) hooked up, it uses its own internal speed sensor and will carry out economy shift patterns like normal.

I have hooked up the lockup converter solenoid to a spare switch on the dash, this pretty much renders mucking around with the VSS pointless for me.

I can also confirm that injector cutoff on decel also still works without the VSS, when I let off at high enough RPM, my wideband clearly shows the injectors shutting off and resuming operation again when I press on the throttle, or idle rpm is greater than vehicle speed (Vehicle creep)

Im now looking into if M1.8 will adapt to non stock injectors being dropped in like the LH2.4 cars do oh so well, what have your experiences been with using the stock management on turbo builds @Lankku? Ive got some bosch 550s that Id like to throw in and see how the ECU handles them

Loving the 6 in the 240 so far, Its a little boring with the auto, but that'll change soon enough hopefully

Some eye candy

AWESOME! Thank you so much for the update! The VSS info is very good to know.
I've been driving mine for a few days now, although on MS2 with the POI controller for the transmission and I have to agree...the B6 is a great engine for these cars.

Sorry for not getting back to you earlier Chad, Life gets in the way from time to time.

When im in the position to, Ill start messing around with the ostrich on the M1.8 and see what I can and cant make it do.
My main objective is to set it up to run a boosted setup, Im still pretty new to the whole tuning game, but atleast if I can nail down the relevant fuel and ign maps, I can point my tuner in the right direction and see what this 90s ECU can really do.

No worries .
I may not be actively pursuing this, but I'm still poking at it from time to time. I've uploaded the files I'm using, but they NEED TO BE RENAMED BEFORE USING.

0261200528.doc becomes 0261200528.xdf

and

0261200528-BIN FILE.doc becomes 0261200528-BIN FILE.bin

This is a work in progress, and there is very little information included in the xdf file. All the maps from the bin file are there, but tuning with them is totally up to you. I'm not responsible for any damage you may do to your car. You've been warned.

Now, I do have SOME theories, and live tracing with an Ostrich would help flesh it all out. The main 16x16 fuel and timing maps are not referenced in the master address table, so if the ecu uses them, it might be for a base/reference value before it applies any multipliers. The single-row maps will possibly be for various things such as WOT fuel/timing, idle fuel/timing, etc. Other early versions of Motronic tune exactly that way, and this file seems very similar to other variants (like on E30 BMWs).

Bump for edit to post #1

Bump

has any progress in the refining or understanding of the m1.8? i just got a ostrich for my 94 960 and hope to get it tuned.