Reverse line pressure boost (80E)
Thread Starter
TECH Enthusiast
Joined: Sep 2016
Posts: 518
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From: North Jersey
Reverse line pressure boost (80E) Ok guy's. need some help. I had my converter re stalled and it it still has issues in reverse. Mainly when the trans is cold.
In reverse, on my compushift controller, the % goes up to 11% at idle.
Micheal Hoy at compushift said "
L,2,R is reverse pressure boost to stop reverse band from slipping, should be set at maybe 12 to 15% and shouldn't change converter behavior ."
I plan on calling him too , but want to hear what others have to say.
Can this setting be set lower or will it affect anything else?
I'm afraid to change it and burn something up.
When it's in drive the % is at zero till I give it gas to move. Shouldn't it be the same in reverse?
Line to lube was done months ago and trans guy said there was nothing in the pan and Circle D said clutch and everything looked good when they opened it up .
The car will idle when the trans is warm (120*) and it will do 10+ in reverse when it's warm.
ANY HELP would be appreciated.
In reverse, on my compushift controller, the % goes up to 11% at idle.
Micheal Hoy at compushift said "
L,2,R is reverse pressure boost to stop reverse band from slipping, should be set at maybe 12 to 15% and shouldn't change converter behavior ."
I plan on calling him too , but want to hear what others have to say.
Can this setting be set lower or will it affect anything else?
I'm afraid to change it and burn something up.
When it's in drive the % is at zero till I give it gas to move. Shouldn't it be the same in reverse?
Line to lube was done months ago and trans guy said there was nothing in the pan and Circle D said clutch and everything looked good when they opened it up .
The car will idle when the trans is warm (120*) and it will do 10+ in reverse when it's warm.
ANY HELP would be appreciated.
Thread Starter
TECH Enthusiast
Joined: Sep 2016
Posts: 518
Likes: 0
From: North Jersey
Ok. I just went out and lowered the LD2 pressure boost to 0 but I also raised my IAC step learning too.
With the trans at 69* it will go in reverse (always did) dip a lil in rpms then catch it self.
I may try to raise the boost back up to where it was when it cools back down to see if that was it or the IAC steps was the culprit.
My money is on the IAC steps.
BTW, it use to stall when the trans temp was <110/120* so this is progress!
With the trans at 69* it will go in reverse (always did) dip a lil in rpms then catch it self.
I may try to raise the boost back up to where it was when it cools back down to see if that was it or the IAC steps was the culprit.
My money is on the IAC steps.
BTW, it use to stall when the trans temp was <110/120* so this is progress!
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
Likes: 33
From: Fort Worth, Texas
"L,2,R is reverse pressure boost to stop reverse band from slipping"
L1,L2,Reverse gets a boost in pressure from the "Reverse Boost" portion of the Boost Valve, This is 100% Hydraulic, & does not need help from EPC/Torque Signal Boost at closed throttle, With throttle/torque applied.....The EPC will add pressure just like it does in forward gears.
L1,L2,Reverse gets a boost in pressure from the "Reverse Boost" portion of the Boost Valve, This is 100% Hydraulic, & does not need help from EPC/Torque Signal Boost at closed throttle, With throttle/torque applied.....The EPC will add pressure just like it does in forward gears.
Thread Starter
TECH Enthusiast
Joined: Sep 2016
Posts: 518
Likes: 0
From: North Jersey
"L,2,R is reverse pressure boost to stop reverse band from slipping"
L1,L2,Reverse gets a boost in pressure from the "Reverse Boost" portion of the Boost Valve, This is 100% Hydraulic, & does not need help from EPC/Torque Signal Boost at closed throttle, With throttle/torque applied.....The EPC will add pressure just like it does in forward gears.
L1,L2,Reverse gets a boost in pressure from the "Reverse Boost" portion of the Boost Valve, This is 100% Hydraulic, & does not need help from EPC/Torque Signal Boost at closed throttle, With throttle/torque applied.....The EPC will add pressure just like it does in forward gears.
just a little paranoid about burning up my trans.
Last edited by wht/73; May 10, 2017 at 10:04 PM.
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
Likes: 33
From: Fort Worth, Texas
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
Likes: 33
From: Fort Worth, Texas
The only reason pressure is boosted in L1 & L2 is to help the Lo/Reverse Band (L1), And the Intermediate Brake Band (L2) hold at closed throttle.
This is very important if towing a heavy trailer down a mountain while using L1/L2 to maintain speed.
Like I said, R/L1/L2 boost is built into the unit & adequate for most applications, The only reason I can think of to need more pressure is a diesel using an exhaust/compression brake while towing extremely heavy.
The EPC will take care of pressure rise anytime your applying Throttle/Torque. Install a pressure gauge.....You will see what I'm talking about.
This is very important if towing a heavy trailer down a mountain while using L1/L2 to maintain speed.
Like I said, R/L1/L2 boost is built into the unit & adequate for most applications, The only reason I can think of to need more pressure is a diesel using an exhaust/compression brake while towing extremely heavy.
The EPC will take care of pressure rise anytime your applying Throttle/Torque. Install a pressure gauge.....You will see what I'm talking about.
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