4L80E safe pressures?

[Picklito]

In the upshift table "Base Shift Pressure vs. Torque vs. Gear" what are safe pressure limits for a stock 4L80E at the various torque settings?

I've got 1->2 and 2->3 scaled from 0 @ 40lb-ft to 84 @ 640lb-ft and those shifts are really nice for my stock truck.
I've got 3->4 scaled from 12 @ 0ft-lbs to 90 @ 520ft-lbs and it's still too soft. How far can I go with pressure on this one?

If I'm approaching maxing out safe pressure, I'll have to go in and enlarge the 4th feed hole. I remember it being really small like .050".

Stock 2005 2500HD 6.0/4L80E 35k miles.
Thanks!

[5FDP]

Post the tune file if you can.

[Picklito]

dave trans 1 2005 6.0 4L80e.hpt

[5FDP]

I don't see why you couldn't add a tad more and see if it helps, maybe another 5-10%.

I'd also disable some of the abuse settings, you aren't going to hurt that 4L80e with stock power. You can disable the transmission abuse setting and the engine side drivetrain abuse setting if you want too.

Past that there can be several more tables you can change to make this truck get out of it's own way. Mainly dealing with Power Enrichment delays and such to help get it in the power sooner.

[Picklito]

Thank you so much. So far, I have only changed transmission settings. Thought it'd be an easier/safer set of calibrations to learn from. I haven't touched the abuse settings because I didn't think the truck would be operating in that range since it sees pretty easy use... but is my thinking incorrect?

As for the engine, I'm open to suggestions. Would like to clean it up a bit, but just for fun. Not a racer, not towing a house. Thanks!

[5FDP]

It's not that you won't be operating in that range but more so that some TM settings can change how the transmission shifts and does it thing. Even though you may not be making a lot of power certain TM settings can dull the shifts. Depending on transmission I normally just remove them so it trys to command the settings I had put in there.


As for power enrichment settings, these are just non fancy changes that can help the "feel" of the truck. Nothing here will hurt it or cause any problems. You can change things differently if you wish too.

Lower the HOT/COLD pedal enable from 90% down to 70%.
Remove the 60 second time delay for PE, set it to 0.0 seconds.
Lower the 5,500 RPM down to 2,000.
Lower the enable torque setting from 100% down to 80%.
Increase the enrichment ramp in rate from .0195 to 2.000. (controls how quickly it brings fuel in, you want it to be quicker)

Lastly under Engine > Torque Mngt > General, there is a table called ETC TPS MAX. It controls the throttle opening for traction reasons. I don't like how it gets in the way sometimes so I always set the table to allow for 100% throttle opening all the time when it's allowed.

[Picklito]

Thanks again! I put those settings in and will see how it goes.

[Picklito]

I'd still like to know what are safe shift pressure settings to use in the vs throttle position tables.

[JohnMattZL1]

In for any updates you may have found. Dad just picked up a H2 SUT with 6.0 and 4L80 so might tinker with it alittle

[kingtal0n]

Bump for more questions!

I have a 4l80e with HD2 shift kit. I want to reduce closed throttle pressures (52psi seems high when 1-2 shifts are like 30psi) but not sure this is wise. No pressure gauge. Im just worried about my pump.