Table Switching via CAN?

[litneon]

Good day guys!

I'm wondering if it's possible to switch AFR tables via CAN bus from my trans controller.

I have an MS3x engine controller and a modified MS2 running my A340e transmission. I'd like to lean out the cruising AFR's a bit, and the only way that I can imagine it really working well would be to allow the AFR or VE tables to switch when lockup engages. I could then create a suitably lean table strictly for no load cruising.

I've had some success with switching the VE table, but my options are limited due to the restrictions on programing switching parameters. There aren't any significant differences between part throttle acceleration and cruising, so to get a lean cruising situation, I have to be willing to have some lean spots in the part throttle accel.

I understand I could build a physical switch relay to pull in the tableswitch input, but that's another thing to do. It seems to me that the logic could be there already to do it internally.

Thoughts?

[dontz125]

It can be done using the MS3 to control the lockup, but I'm assuming you get better lockup quality using the trans controller.

Is there any sort of switch - pressure, position, limit - that the transmission uses to tell itself that it has achieved lockup? *That* would probably be your best bet.

Perhaps you could pester - I mean, nicely ask James to have 'lockup' as a datapoint fed back from the trans box, in addition to VSS & gear.

[whittlebeast]

There are plenty of ways to do that but we need a data log.

Andy

[litneon]

I can attach a datalog, but what do you want to see? A log of cruising? Part throttle accel? My question was about table switching, not the actually tune itself. Is that more a hardware question that should be in another section?

@dontz125: No, there isn't anyway to know whether it actually locked up. But unless the clutches fail in the convertor, there shouldn't be any issue there. If I have to do a physical switch, I'll just build a relay for the table switching input. Was hoping it could be simpler just to eliminate clutter. It seems to me that the data is there if I can get to it... Haha.

[whittlebeast]

I can attach a datalog, but what do you want to see? A log of cruising? Part throttle accel? My question was about table switching, not the actually tune itself. Is that more a hardware question that should be in another section?

Just typical driving. To get mileage, you need to see there the motor spends most of it's time.

[litneon]

Copy that. I'll edit a couple in the next day or so and attach them. I'll add both a cruising and accel. The MAPDot travels through the same cells on both, which is why I want to table switch. I've been switching based on TPS, but finally gave up on that and because both cruising and part throttle accel are both below the 25% where I was switching.

It may be one of the curses of the auto trans...

Thanks for the response! I'll get back as soon as I can. Traveling today for work.

[prof315]

Another possible idea to throw out here. ( and then this thread really should be moved to MS3 development )
What about using the engine states in MS3 firmware 1.5? Activate table switching once the engine in is "cruise" state for x amount of time....

[whittlebeast]

This happens to be a Harley data log but it is all the same thing. The big area in red is where this motor spends most of it's time and is where you want to be close to 14.7 or slightly leaner to get mileage. Adding timing really helps in this area. Your area will be slightly different but all motors are all similar.

http://www.nbs-stl.com/HarleyTuning/Big ... 20Hits.png

In the left is the gear chart. The top line is 6th gear.

Andy

[litneon]

Yeah, I can GET good mileage cruising. I figured out how to do that a long time ago. But, I struggle to get both good mileage cruising and keep from being lean under acceleration. Since the MapDots travel through the same area, I can't get it to do two different things. ie. be in the 13's for accel and the 15's for cruising.

My truck is real happy to run 15.5-16 on the highway, and doing so gets low 30's mpg. But then it lacks power and runs too lean even in a mild acceleration. If I do a hard accel, it runs in a different part of the map and makes boost real fast.

I'm in Mexico for work, and have to go to eat dinner, so I'll edit a couple log clips and post them up later this evening.

Thanks guys!

[litneon]

Well shoot. Apparently I don't have a log of highway cruising. I'll have to make one upon my return home. I do have lots of examples of part throttle accel. Attached should be my .msq and a .msl.

[litneon]

Here is a current log with both part throttle accel AND highway cruising. The EGO correction is around 85% in BOTH circumstances because the AFR map is leaned out for highway mileage. Highway AFR's are ok, although it can run way leaner. I don't want to see those numbers during accel though... Haha.

[whittlebeast]

What is this motor?

[litneon]

It's a 1994 Toyota pickup sporting a 22re.

[litneon]

I can also list some of the mods done...

Aeromotive Stealth fuel pump, A1000 FPR, Injector Dynamics ID1000's, wasted spark, PT5858 dual BB, custom header, CP forged pistons, Eagle H-beams, ARP everything, Cometic MLS HG, LC Engineering high volume poil pump, Schneider State 2 turbo cam, LC oversized valves, dual valve springs, and titanium retainers. Oh, and a ported head. 8.5:1 compression, although if I had it to do over, I'd keep the stock compression.

[whittlebeast]

I have done table switching before on really hyper motors but that is not the the issue here.

Here is what a data log of a fairly typical turbo motor looks like. This is looking at fuel in this screen shot.

http://www.nbs-stl.com/tuning/Tuned%20T ... 20Fuel.png

The log you posted is about 1 percent of the story of what your motor is doing. It is a little like telling how rich a guy is based on he has a $100 bill in his wallet. All we know is he has $100.

We need more data. I would set the entire AFR table to 14 below 75 KPA and then slide the AFR to say 12.4 AFR at 150 KPA and get a bigger log to see what is going on. Stay out of the boost for now till we see some of the patterns on what this motor wants. Go to a single VE tune for now.

Andy

[whittlebeast]

If you have the HD version of MLV, you can generate a Histogram giving the average AFR for the motor.

http://www.nbs-stl.com/tuning/Tuned%20T ... ograph.png

Have fun tuning

Andy

[jsmcortina]

I had a look at your logs yesterday. The first thing that struck me was how large your cruise kPa was. Seems odd. However, you accel kPa is clearly distinguished as it is around 90kPa.

I do wonder if there is a mechanical or tuning issue leading to such high kPa ("low vacuum")
If that is correct then you should adjust the breakpoints in the VE and AFR tables to give you more resolution in the 80-90 kPa region.

Also if you are at 85% EGOcor all this time then your VE table needs adjusting.

James

[prof315]

I had a look at your logs yesterday. The first thing that struck me was how large your cruise kPa was. Seems odd. However, you accel kPa is clearly distinguished as it is around 90kPa.

I do wonder if there is a mechanical or tuning issue leading to such high kPa ("low vacuum")
If that is correct then you should adjust the breakpoints in the VE and AFR tables to give you more resolution in the 80-90 kPa region.

Also if you are at 85% EGOcor all this time then your VE table needs adjusting.

James

He's got a smallish ball bearing turbo on the engine. The cruise kPa is high because the turbo is already in partial spool during cruise. Does awesome things for dropping the pumping losses but it does make tuning a little odd.

[whittlebeast]

This thread may help some.

http://www.msextra.com/forums/viewtopic ... 34&t=65200

Andy

[litneon]

Thanks for the responses guys. I'll get some more info for you if I can.
The hard part for me is getting all the info you desire in one or multiple logs (I think). I apologize for not having a full understanding of the complexity of these things. I realize there's a lot going on all at once. I'll read up on it more when I get off work today. I'm back home at least...