Colorado 6L50 line psi

DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
I've been messing around with my 17 Colorado. How much line psi can these handle without causing problems on a stock transmission? The line psi table by RPM/Gear in EFI live shows 105. The max line PSI table shows 275 with a max clutch psi of 218 and a max PCA of 110.

I was able to clean up the stock "lazy" shifts but I also want to also increase the holding power without hurting something. The truck IS tuned with a DSP4 switch.

Thanks.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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Moved this into Mike's Trans Talk. I dont think too many people look in the Colorado forum.
 

Mike L.

Got Sheep?
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Aug 12, 2006
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Put a gauge on it. The numbers you are reading are probably fixed numbers. Pressure is raised by tuning. I would start at 20% increase and see how it feels. Anything higher and you will start to get weird downshift clunks especially when you are in 6th gear at 45mph at 1100 rpm's and you roll into the throttle. It can get some nasty clunks at low speeds with incresed pressure. Both the 6L's and 8L's suck big time. I hate my 8L90 in my GMC.
 

DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
Put a gauge on it. The numbers you are reading are probably fixed numbers. Pressure is raised by tuning. I would start at 20% increase and see how it feels. Anything higher and you will start to get weird downshift clunks especially when you are in 6th gear at 45mph at 1100 rpm's and you roll into the throttle. It can get some nasty clunks at low speeds with incresed pressure. Both the 6L's and 8L's suck big time. I hate my 8L90 in my GMC.

Time to back it down then it has the weird downshift clunks...What kind of torque can these hold? This 2.8l is very torquey with tuning. The converter feels like it has a partial lockup (or its slipping) when I roll into the power in the higher gears. On the scanner I can watch it slip then it will finally fully lock and stop slipping.

Haven't had much luck finding aftermarket support for this transmission.Do you plan on offering any upgrades for this transmission? Thanks.
 

onebaddmaxxx

Active member
Feb 22, 2009
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Cecil County Md
They are actually little brothers to the 6l80/6l90. Most of the same parts carry over (you can do a ZIP kit and 6l80-lb1 line booster) in them to mechanically enhance the trans. The 6L platform is very tedious to tuning and you can ruin it in a hurry.
 

DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
They are actually little brothers to the 6l80/6l90. Most of the same parts carry over (you can do a ZIP kit and 6l80-lb1 line booster) in them to mechanically enhance the trans. The 6L platform is very tedious to tuning and you can ruin it in a hurry.

I did find the zip kits, checking with sonnax to make sure they fit. Will a 6L80 converter fit in this particular 6L50? I talked to a few shops who do converters for 6L80s and they were not sure if they would fit. Initially the answer was "yes", until I told them what the transmission was in. I called a few diesel trans shops, ATS, Suncoast , DPC, and Revmax. Revmax has some stuff being tested, but it will be a few months before they release anything. Thanks.