GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

Built tranny shift question~1-2 shift killing me

Thread Tools
 
Search this Thread
 
Old Sep 4, 2005 | 01:20 AM
  #1  
1SlowHoe's Avatar
Thread Starter
Destroyer of Transmissions
iTrader: (28)
 
Joined: Feb 2005
Posts: 4,962
Likes: 1
From: Orlando, FL
Default Built tranny shift question~1-2 shift killing me

Before I installed a "built" tranny I had a tune that beefed up line pressure. My tuner gave me this info "Commanded PCS line 'amperage" at WOT is under 0.10 amps which will command over 185 PSI"
The new tranny however, has the accumulators blocked off. So I'm wondering if the raised line pressure combined with the accum. being blocked is the reason for my neck breaking 1-2 shift at partial throttle? I live on a clay road and if I go slow (under 10 mph) the 1-2 shift is so harsh it actually activates the traction control because the rear wheels break loose. I can see the digs in the dirt after I roll a few more feet. People actually hold thier drinks until after I shift to 2nd 'cause they don't want to spill them Needless to say this is annoying. At WOT the shifts are great. Any ideas? Anybody nearby with software to adjust this? I have no software at all.
Reply
Old Sep 4, 2005 | 02:30 AM
  #2  
02sierraz71_5.3's Avatar
TECH Junkie
iTrader: (2)
 
Joined: Oct 2004
Posts: 3,473
Likes: 1
From: Cornelius, NC
Default

there is a shift modifier for the 1-2 have your tuner change the table

here is mine

2 1 -1 -2 -2 0 0 0 0 0 0 0 0 1 2 5 6
3 2 -1 -2 -2 0 0 0 0 0 0 0 0 2 4 6 7
5 4 0 -3 -3 0 0 0 0 0 0 0 1 2 5 7 8
7 6 1 -4 -4 0 0 0 0 0 0 0 2 3 6 8 9
10 8 2 -6 -6 0 0 0 0 0 0 0 2 4 7 9 10
Reply
Old Sep 4, 2005 | 12:42 PM
  #3  
OCBC's Avatar
TECH Regular
iTrader: (1)
 
Joined: Aug 2004
Posts: 464
Likes: 0
From: Yorba Linda, CA
Default

From my understanding, you should have stock line pressures with any shift kit.
Reply
Old Sep 4, 2005 | 12:45 PM
  #4  
Mr. Sandog's Avatar
TECH Veteran
 
Joined: Mar 2004
Posts: 4,632
Likes: 2
From: Sun Diego
Default

Originally Posted by OCBC
From my understanding, you should have stock line pressures with any shift kit.


Or at least start with the stock settings, then modify as desired.

I returned my tranny settings to stock (from Magnuson's beefed-up Radix settings) right after installing my shift kit, and before driving on it. As of right now, I am still driving on the stock tranny settings, and they are fine.

Shift kits are made to work with the stock transmission programming.
Reply
Old Sep 4, 2005 | 01:45 PM
  #5  
02sierraz71_5.3's Avatar
TECH Junkie
iTrader: (2)
 
Joined: Oct 2004
Posts: 3,473
Likes: 1
From: Cornelius, NC
Default

is it vacumm modulated or do the stock electronics still control line pressures?
Reply
Old Sep 4, 2005 | 03:06 PM
  #6  
1SlowHoe's Avatar
Thread Starter
Destroyer of Transmissions
iTrader: (28)
 
Joined: Feb 2005
Posts: 4,962
Likes: 1
From: Orlando, FL
Default

Originally Posted by 02sierraz71_5.3
is it vacumm modulated or do the stock electronics still control line pressures?
As far as I know it is the electronics. I know the computer is what was programmed to increase the line pressure when I had the stock tranny. I have never had it adjusted to work well with the new tranny. I'm guessing if I drop back to stock line pressure I will get what I am looking for. I just don't know anybody in the panhandle of FL that has any edit software.
Reply
Old Sep 4, 2005 | 03:26 PM
  #7  
OrlandoFL4.8's Avatar
TECH Resident
iTrader: (1)
 
Joined: Oct 2004
Posts: 941
Likes: 0
From: Orlando
Default

I just got my tranny built, I believe from the same place you did based on a brief converstation we had a week ago and mine does the same thing. The 1st to 2nd shift is a killer under light throttle. I had firm shift settings on my VHP tuner prior to the tranny build, so I am wondering the same thing.
Reply
Old Sep 4, 2005 | 05:54 PM
  #8  
02sierraz71_5.3's Avatar
TECH Junkie
iTrader: (2)
 
Joined: Oct 2004
Posts: 3,473
Likes: 1
From: Cornelius, NC
Default

Some builders go with a vacuume modulator if that is the case you can adjust line press with a flathead.

If not set the force motor table to STOCK and adjust the 1-2 shift under upshift pressure modifier

this is the table I ended up with and it works well for just a trans go shift kit
-7 -7 -6 -4 -1 0 0 0 0 0 0 0 0 1 2 5 6
-7 -7 -6 -4 -1 0 0 0 0 0 0 0 0 2 4 6 7
-7 -7 -6 -4 -1 0 0 0 0 0 0 0 1 2 5 7 8
-7 -7 -6 -4 -1 0 0 0 0 0 0 0 2 3 6 8 9
-7 -7 -6 -4 -1 0 0 0 0 0 0 0 2 4 7 9 10
Reply
Old Sep 4, 2005 | 07:23 PM
  #9  
1SlowHoe's Avatar
Thread Starter
Destroyer of Transmissions
iTrader: (28)
 
Joined: Feb 2005
Posts: 4,962
Likes: 1
From: Orlando, FL
Default

How could I tell if it is vac modulated by looking at it?
Reply
Old Sep 4, 2005 | 08:08 PM
  #10  
02sierraz71_5.3's Avatar
TECH Junkie
iTrader: (2)
 
Joined: Oct 2004
Posts: 3,473
Likes: 1
From: Cornelius, NC
Default

Originally Posted by 1SlowHoe
How could I tell if it is vac modulated by looking at it?
call the guy who built it
Reply



All times are GMT -5. The time now is 07:09 AM.