How's my SD Tune looking? Critique and criticize please!

[cabech984]

New to tuning and have been messing with the SD portion of the tune all week after completing a 4L80e swap to my cammed 2006 Silverado 5.3L L59. I tuned the MAF over the winter, smoked the stock 4L60e while doing SD tuning, and pieced together a 4L80e swap using a junkyard 4L80e from an early 2000's 2500hd. I'm running an OS from a 2006 1500hd Silverado and using it's 100% as found 4L80e tune file. The engine seems to be running pretty well and the transmission isn't bad considering I paid $200 for it. I'd like to know what some of the more seasoned tuners on here think before I move on to some timing tuning etc.

Things I've noticed during log that I'm including:

1. The 4L80e has a harsh WOT 1-2 shift, not sure if it's tuning related just a beat up old transmission. Doesn't feel like its slipping and part throttle/cruising shifts feel firm, but okay to me
2. Had some KR during the pull around 7:17 in the log, but didn't have any during the pulls at 7:15, 7:25 and 7:32 in the log.
3. Didn't realize my high and low octane spark tables aren't the same, I read it refers to the Low octane table in SD tuning with the MAF disabled?
4. Had a bunch of lean cells in the 2800rpm range that weren't an issue on the previous log

I still have to tune the transmission, spark table, and power enrichment. This thing feels like a dog from a stop. I am running a factory torque converter in this setup. I'm building a 4L80e from a 2009 express van using a stage 4 Jakes transmission rebuild kit, this transmission was simply put in as a stop gap, but it seems like a good unit, so it might stay for awhile ha.

Log 16.hpl
SD Step 15.hpt

I'd appreciate any advice, suggestions, grilling, etc that you have. I'm new to this but have all the tools to get it done except the experience! Thanks!

[5FDP]

Yes, the low octane table is used in speed density only. Copy over your high octane table and work it from there. It's got more power in it once you get the timing up. Should have no problems running 22-25 degrees of timing in a truck.

For sure alter your PE settings and torque mngt settings, that will help a lot. The PE is pretty fat and the engine side TM is basically stock and should be changed to help it out.

Raise the MAP kpa enable to 80kpa, lower the rpm enable to 1,500rpm, lower the enable torque to 50% and lower the hot/cold pedal enable to 65% throttle. In the EQ ratio put 1.200 in the 3,600rpm and carry that number throughout the rest of the table. That will be a safe AFR to target for now.

In the TM tab, raise the max torque vs rpm table way up. In the ETC limits set the ETC TPS MAX to 100% for all cells, that should let the blade open as quickly as possible. In the abuse section raise the rpm to 7,000 and set the speed to zero. Also if you go to the systems tab, click on systems options and put a zero in the brake torque mngt box to turn that off.


Just doing those simple settings should help. The VE does need more work and the high numbers up top should come down. There shouldn't be a need to have numbers over 100 with larger injectors like you have, you'll see that it's too rich up there.

Also part of the reason it's so slow from a stop is because of your tire size and rear end gears. Having 32's with 3.23's is a major hurdle to overcome, this truck really needs 3.90's or 4.10's to work with that tire size and the 4L80's first gear ratio.

[cabech984]

Thanks for the quick reply, 5FDP! I?ll definitely make the changes once I get back to tuning next week

[kingtal0n]

Probably want to LOG EPC current, and put a transmission pressure gauge on it and make sure you are getting the correct pressure




My stock 4l80e data and all of the OEM stuff I've seen was way off, pressure too low for my setup. The pressure depends on vehicle weight, tire size, gear ratios, not just torque of the engine. In my swap the 4l80e didn't slip using OEM values at first but once I dropped the rear gear and increased tire size it started to slip alot with the OEM pressure. My mistake for not putting a gauge on it.

[cabech984]

Probably want to LOG EPC current, and put a transmission pressure gauge on it and make sure you are getting the correct pressure

Will do, I was actually considering throwing my pressure gauge on it. I kept telling myself that these settings (that I have no idea what I?m looking at in HP tuners) are based around a truck that weighs a few thousand more pounds than this little truck lol

[cabech984]

Probably want to LOG EPC current, and put a transmission pressure gauge on it and make sure you are getting the correct pressure

I'm unable to fine EPC current in the channels, are you talking about force motor current? Thanks for the help btw!

[kingtal0n]

Yes EPC current is Force motor current, it should drop like a rock when you hit the gas

[cabech984]

Yes EPC current is Force motor current, it should drop like a rock when you hit the gas

So, went out and logged again today on a 30 minute drive. Everytime I went to 100% throttle, the force motor current would drop down into the 240-270mA range, didn't appear to go any lower. In drive idle was around .78A. Should that be closer to .98A per that chart? I haven't gotten a line pressure gauge on the transmission yet, I'll probably get to that on Thursday.

[cabech984]

Also, during my drive earlier, I was in stop and go traffic while merging on the highway and the truck shut down and went into reduced power mode. I was able to clear the DTC's and make it back home, but like an idiot didn't write them down. I believe there was a P0068 code and another MAF code(along with my failed maf code for SD tuning. I actually thought the datalog would save the DTC's it had during the run

[kingtal0n]

So, went out and logged again today on a 30 minute drive. Everytime I went to 100% throttle, the force motor current would drop down into the 240-270mA range, didn't appear to go any lower. In drive idle was around .78A. Should that be closer to .98A per that chart? I haven't gotten a line pressure gauge on the transmission yet, I'll probably get to that on Thursday.

Can't tell what the pressure is without a gauge. That is the one critical step to tuning the transmission. With the gauge simply dial as needed. otherwise its just guessing.
My trans was slipping with .257~ amps once I dropped the rear gear from 4.11 to 3.5, added 1" diameter to the tires and added 10psi of boost. It's pretty easy to change a pump in the 4l80e so I am not shy with the pressure. The only reason not to use full pressure is to gain some longevity from the pump, if you think the trans doesn't need the pressure somehow (how can we tell without slipping it first though?). Its like a choice between "do I want to potentially slip the trans and shred my clutches or do I want to use an unnecessarily high amount of pressure and wear out the pump sooner".

I've heard from reputable source that shooting for around 200psi at WOT with 500-600rwhp 4l80e is typical. You may extrapolate that however you see fit. I am by no means a transmission pressure tuning expert- I only know mine doesn't slip and that they aren't difficult to rebuild.

[cabech984]

Can't tell what the pressure is without a gauge. That is the one critical step to tuning the transmission. With the gauge simply dial as needed. otherwise its just guessing.

So, I threw my line pressure gauge on the 4L80e and my pressure in P/N/D is 80psi at idle. at WOT, its bouncing around 180psi. Reverse is 130psi. I used the bluecat transmission tool to change my shift rpm and speeds and it definitely seemed to help with some of the harsh shifts so far.

What table do I modify to adjust the Force Motor Current. Manually controlling it in the VCM scanner, I can get 55-60psi at 1500rpm using 910mA. thats all I've verified

[kingtal0n]

There is a literally a table called force motor current. I Modified it heavily in my application because the OEM ecu has some kind of behind the scenes pressure algorithms which would cause pressure to drop unexpectedly at some points, and because the torque management reflects into it as well. So for example when pulling timing for a shift the computer determines how much torque was taken out, but the calculation is wayyyy off when running forced induction because the engine is producing two or three times the torque that it was when stock during a shift.

You can use a combination of force motor and shift pressure to dial in the pressure you desire. There is also a max pressure setting to cap off the total amount of force motor current... this way you can "MAX" the numbers in the shift pressure without worrying about going overboard with too much pressure.

[cabech984]

There is a literally a table called force motor current.

Gotcha, I've been messing around with tuning again this week as time allows and haven't modified the FMC table, but I've been messing with the pressure tables for shifts. I want that 190psi throughout WOT and just not during shifts, right? I'm able to control it thru the shift by modifying the shift pressure tables, but itll go back to the 150psi (450mA) range after the shift. I can change that thru the force motor current table, right? I just don't want to fry anything!

After that, I need to iron out the VE table, add some timing, and iron out the power enrichment and I think itll be done until I can get on a dyno. I went back to MAF enabled and seems to be 8-9% on the LTFT's, so I believe theres work needed!
wot 12 shift test.hpl
test 2.hpt

[kingtal0n]

The low current like 100mA~ is for WOT only, its holding pressure for wot and the wot shifts. NOTHING to do with part throttle or cruise pressure.

For cruise you want as low pressure as possible to extend the life of the trans. I think I cruise 800-950mA most of the time. It depends on the transmission and internal mods like lube-to-line orifice which may call for lower current to make up for losses at the pump. That is why you need the trans pressure gauge.

For a shift at part throttle, the pressure required or desired depends on how the trans is build, like the clutch clearance and shift plate orifice diameters, even the type of friction materials and end play characters and sprags all have an influence. For part throttle my method is basically going by feel. You want a positive shift, with no harsh or slamming behavior, its pretty intuitive but can be difficult to find the sweet spot because of the way we have to stop and re-upload a new file each test. My method is this, I program two different shift tables with slightly different pressures (for 60e and 80e all that matters is pressure because its the only thing electronically controlled- everything else is inside the trans we have no control unless rebuilding it) And use the shift momentary ground activated trans map feature that lets you jump back and forth between trans maps to try each different settings. Try A, then try B, then A again, etc... and keep the one thats better, then program the other one differently, and go again. Its alot like going to the eye doctor "Which one is better, #1 or #2" Then they try #3 #4 #5 etc... against the best one. I like my part throttle to skip the tires, "chirp" On the shift with enough throttle input, some people don't like it or their trans can't handle it well enough, its really really important to know how the trans is built in order to understand what kind of behavior IS and ISN'T possible at part throttle. WIth WOT though, you basically just need as much pressure as possible to keep from slipping IF possible, Just think of a TV cable for a old school 700R4 or something... The cable pulls all the way out with WOT position so there isn't really anything to test or debate about. You give her all shes got and if it isn't enough... oh well... its a trans build issue not a tuning issue.

[cabech984]

The low current like 100mA~ is for WOT only, its holding pressure for wot and the wot shifts. NOTHING to do with part throttle or cruise pressure.

Thanks for clearing that up, it was starting to make sense after making changes and watching realtime. My issue is, that under WOT conditions, it seems to only command 60-80% line pressure until it commands the shift, then itll spike up to 180-190psi. My Torque output isn't in the range to command higher and haven't added timing to the tune to make more power yet. I think I have my MAF tune, and PE where I want it, just been ironing out the SD Tune and struggling with this transmission tuning haha. I appreciate the help and guidance for sure!

And use the shift momentary ground activated trans map feature that lets you jump back and forth between trans maps to try each different settings.

By this, do you mean Tow/Haul mode? Or am I missing something