WOT shifting...
03-20-2009, 01:40 AM
#1
WOT shifting... i have been reading a lot lately with some cars not shifting when they were commanded to shift. i recently had my car tuned and noticed the same thing. when i read on here i see the car shifting AFTER the commanded shift point. the problem i was having was the car was shifting BEFORE the commaned RPM shift point. it was usually around 200 RPM's early give or take. i really want the car shifting around 6400 with my modifications but we didn't want to raise the commanded RPM shift table too high (6600 rpm's, for example) in order to get the car to shift around 6400 RPM's. any suggestions? off the top of my head i do not know what the MPH tables are set at.
03-21-2009, 02:31 PM
#3
TECH Fanatic
Join Date: Feb 2004
Location: Lexington, KY
Posts: 1,259
Likes: 0
Received 0 Likes
on
0 Posts
Are you going by the tach or by data logging software? The tach is notoriously slow. If the data logging software is what you are looking at, probably your only option is to raise the commanded rpm shift point a little.
03-21-2009, 03:45 PM
#4
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
Monitor your TPS -voltage- at WOT looking for anything
over 4.75V; that will trigger a fault mode that short-
shifts, but you may not stay in it long enough to set
the code. This is probably the most common cause of
early shifting.
Now, if you're going by the tach and eyeball, that's
another matter; tach is lagging reality by a bit.
over 4.75V; that will trigger a fault mode that short-
shifts, but you may not stay in it long enough to set
the code. This is probably the most common cause of
early shifting.
Now, if you're going by the tach and eyeball, that's
another matter; tach is lagging reality by a bit.
03-22-2009, 12:32 PM
#6
I'm using Tunercat OBD2, so not sure on table names being same, but on my pickup with 5.3/4l60E, changes to the Normal Mode WOT Shift Speed vs Shift takes effect before the Normal Mode WOT Upshift RPM vs Shift.
I think it goes by what is lower:
If 40 MPH in 1st = 5500 RPM
and 1-2 upshift RPM is 5700.
I think it will make the 1-2 shift at 5500 rpm, or 40 mph. If you were to raise the MPH to a point where RPM will be above 5700, it may use the upshift RPM table instead. play around, see what you figure out , report back.let me know.
I think it goes by what is lower:
If 40 MPH in 1st = 5500 RPM
and 1-2 upshift RPM is 5700.
I think it will make the 1-2 shift at 5500 rpm, or 40 mph. If you were to raise the MPH to a point where RPM will be above 5700, it may use the upshift RPM table instead. play around, see what you figure out , report back.let me know.
