PCM reflash to take out the lockup convertor
10-19-2008, 06:58 PM
#1
Teching In
Thread Starter
Join Date: Oct 2006
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
PCM reflash to take out the lockup convertor
Posted yesterday about my 02`6.0 2500HD. The 7000 lbs trailer weight is not enough to keep the lockup convertor from locking. Thus it seems to be just out of it`s torque curve while towing. 70 mph @ 2000-2100. 65 is around 1800 or so. 285 tires which are a bit taller then the stock 265`s.
How about a reflash on the PCM that unlocks the convertor while in the tow/haul mode ? That would bump my RPM up a couple hundred or so and let the engine run in is sweeter spot.
Or perhaps wiring in a switch to turn the lockup off when towing ? If a reflash will not do it.
Thoughts or comments ?
How about a reflash on the PCM that unlocks the convertor while in the tow/haul mode ? That would bump my RPM up a couple hundred or so and let the engine run in is sweeter spot.
Or perhaps wiring in a switch to turn the lockup off when towing ? If a reflash will not do it.
Thoughts or comments ?
10-19-2008, 07:21 PM
#3
Teching In
Thread Starter
Join Date: Oct 2006
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
As a counter point, not to argue at all. How about the folks running a much heavier trailer that does not allow the convertor to lock up ? If it matters the trans does have the factory trans cooler in it. Part of the trailer/snow plow package.
10-19-2008, 07:27 PM
#4
IDK what you mean by that. I've never heard of a situation where a truck stayed unlocked towing. you're more likely to end up in 3rd gear.
The stock cooler is no match for towing unlocked.
FYI, my 5.3 with a small cam pulls 10K# locked pretty well.
Your 4l80 with taller tires will be about the same final gear ratio as mine.
The 6.0 is a stout motor and a new cam at 100K is nothing new around here.
The stock cooler is no match for towing unlocked.
FYI, my 5.3 with a small cam pulls 10K# locked pretty well.
Your 4l80 with taller tires will be about the same final gear ratio as mine.
The 6.0 is a stout motor and a new cam at 100K is nothing new around here.
10-19-2008, 07:42 PM
#5
Teching In
Thread Starter
Join Date: Oct 2006
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
IDK what you mean by that. I've never heard of a situation where a truck stayed unlocked towing. you're more likely to end up in 3rd gear.
The stock cooler is no match for towing unlocked.
FYI, my 5.3 with a small cam pulls 10K# locked pretty well.
Your 4l80 with taller tires will be about the same final gear ratio as mine.
The 6.0 is a stout motor and a new cam at 100K is nothing new around here.
The stock cooler is no match for towing unlocked.
FYI, my 5.3 with a small cam pulls 10K# locked pretty well.
Your 4l80 with taller tires will be about the same final gear ratio as mine.
The 6.0 is a stout motor and a new cam at 100K is nothing new around here.
Glad to hear about the stout(nes) of the 6.0. As the original owner I can attest to the care it has been given over its life. So a 100,00 mile 6.0 would not be out of reason for a mild cam swap ? Was thinking of worn lifter bores (as in a ridge at the top of the OEM bore) or valve stem deposits that might interfer with a higher lift cam.
Any cam you might want to sugguest ?
Maybe a set of higher ratio rockers instead ? Thought I saw an add from Comp Cams about some new rockers they were offering.
Recall when I was playing with Pontiac GTO`s and Trans Ams, the old stuff
Changing from the stock 1.5`s to a set of 1.65`s made a pretty big differance. Does the 6.0 respond to this ?
Trending Topics
10-19-2008, 09:16 PM
#8
Teching In
Thread Starter
Join Date: Oct 2006
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
The 285`s are starting to get thin. I may go back to the 265`s, but dang I hate to do that.
Another point I did not mention. The truck has the Cognito leveling kit on it. Say about 4 inches of lift. That is not helping with the added wind drag.
10-21-2008, 06:06 PM
#10
TECH Fanatic
Join Date: Oct 2005
Location: Woodstock Ontario Canada
Posts: 1,379
Likes: 0
Received 0 Likes
on
0 Posts
Get a PCM tune, the 6.0 HD engines are very detuned stock. Sounds like you need gears, or pull the gear selector out of OD and tow in 3rd.
Towing unlocked will get HOT, as mentioned.
http://www.nelsonperformance.com/
peace
hog
Towing unlocked will get HOT, as mentioned.
http://www.nelsonperformance.com/
peace
hog