4L80 Perf tune?

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08-05-2014
Scrufdog

4L80 Perf tune?

Ive read a bunch of threads with people bouncing around ideas on how to do a nice performance tune on a 4L80, but havent really picked up on any settings that anyone has actually used. Anyone care to share, or give a good idea?

16197427, $31, BNKM

Thanks
08-08-2014
buddrow

Get with EagleMark, he like's to use one for a Caddy if I remember correctly but don't remember more than that. You can play around with the shift times for starters. Lower them by say maybe 5-10% and drive it to see how it feels. I'm not familiar with that mask but I may have a look later. I don't have a comparable vehicle to test on so you're on your own there lol.

Buddrow
08-08-2014
Scrufdog

I already cut the shift times in half and half again, and raised the max line pressure to 94. Not feeling much of a difference though. I'm guessing I need to tweak line pressure tables, but there are so many, I dont know where to start.
08-08-2014
Fast355

Quote:

Originally Posted by Scrufdog

I already cut the shift times in half and half again, and raised the max line pressure to 94. Not feeling much of a difference though. I'm guessing I need to tweak line pressure tables, but there are so many, I dont know where to start.

WOT you will not feel much difference unless you modify the valve body or adjust the EPC. You can make a big part-throttle shift pressure change, but WOT is pretty much maxed out already from the factory.
08-08-2014
Scrufdog

yeah, i looking mostly for part throttle changes. My 97 has a custom PCM from an aftermarket diesel supply, and it shifts like a dream. Damn thing will break your head of your shoulders if you let it, thats what I'm looking for.

So any hints on where to start?
08-08-2014
Fast355

Quote:

Originally Posted by Scrufdog

yeah, i looking mostly for part throttle changes. My 97 has a custom PCM from an aftermarket diesel supply, and it shifts like a dream. Damn thing will break your head of your shoulders if you let it, thats what I'm looking for.

So any hints on where to start?

The Express shifts like a dream as well. I used the factory tow/haul line pressure from an 2002 Express with an 8.1. Then quickened the shift times. If I get a chance this weekend I will post up the tables. They will not be exactly like the older stuff, but should be able to get you started. My valve body also has a Transgo HD2 kit installed and the EPC cranked 1/4 turn for higher pressrue. It will chirp the tires going into 2nd @ 50 mph.
08-08-2014
Scrufdog

Quote:

Originally Posted by Fast355

The Express shifts like a dream as well. I used the factory tow/haul line pressure from an 2002 Express with an 8.1. Then quickened the shift times. If I get a chance this weekend I will post up the tables. They will not be exactly like the older stuff, but should be able to get you started. My valve body also has a Transgo HD2 kit installed and the EPC cranked 1/4 turn for higher pressrue. It will chirp the tires going into 2nd @ 50 mph.

That would be awesome. Thank you.
08-12-2014
buddrow

Keep in mind, the harsher the shift the harder it is on the internal components inside the transmission. Just food for thought. With that being said, if you're in northeast Oklahoma by all means crank that puppy up and when you snap something inside gimme a shout and Ill fix you up with a new trans. :)

Buddrow