Shifts early into OD, can tuning fix this?
#1
Shifts early into OD, can tuning fix this?
My Corvettes tranny shifts into overdrive way too early for my liking (at part throttle), at only 40mph it'll do it, and it almost lugs the engine. And it takes a lot of throttle pressure to force a downshift at this point too.
When I got my car dyno tuned by ARE, he looked for something in the transmission section of the software which would correct this problem, but he couldn't find it.
I'm wondering if perhaps there is a different tuning program that might do it. I'm honestly not sure which program ARE uses for their tuning though.
When I got my car dyno tuned by ARE, he looked for something in the transmission section of the software which would correct this problem, but he couldn't find it.
I'm wondering if perhaps there is a different tuning program that might do it. I'm honestly not sure which program ARE uses for their tuning though.
#2
Originally Posted by Patman
My Corvettes tranny shifts into overdrive way too early for my liking (at part throttle), at only 40mph it'll do it, and it almost lugs the engine. And it takes a lot of throttle pressure to force a downshift at this point too.
When I got my car dyno tuned by ARE, he looked for something in the transmission section of the software which would correct this problem, but he couldn't find it.
I'm wondering if perhaps there is a different tuning program that might do it. I'm honestly not sure which program ARE uses for their tuning though.
When I got my car dyno tuned by ARE, he looked for something in the transmission section of the software which would correct this problem, but he couldn't find it.
I'm wondering if perhaps there is a different tuning program that might do it. I'm honestly not sure which program ARE uses for their tuning though.
#4
In hptuners you get there through
Edit,
Transmission,
A4 Shift Speed
Then there are buttons for Normal, Cruise, Hot, and Performance.
For example here is my Normal table.
Gear -------------------------TPS----------------------------
Chng 00 06 12 19 25 31 37 44 50 56 62 069 075 081 087 094 100
==== == == == == == == == == == == == === === === === === ===
1->2 12 12 12 12 14 17 20 22 26 29 30 032 032 032 040 043 043
2->3 22 22 22 24 26 31 38 42 47 51 56 060 065 070 075 082 082
3->4 30 32 34 36 40 46 52 80 85 90 95 100 105 110 120 134 134
2->1 08 08 08 08 08 08 08 08 08 08 08 008 008 008 008 008 035
3->2 14 14 14 15 17 19 22 23 26 29 32 034 037 041 046 053 065
4->3 20 20 22 23 26 30 34 39 44 51 61 076 080 085 090 100 105
Edit,
Transmission,
A4 Shift Speed
Then there are buttons for Normal, Cruise, Hot, and Performance.
For example here is my Normal table.
Gear -------------------------TPS----------------------------
Chng 00 06 12 19 25 31 37 44 50 56 62 069 075 081 087 094 100
==== == == == == == == == == == == == === === === === === ===
1->2 12 12 12 12 14 17 20 22 26 29 30 032 032 032 040 043 043
2->3 22 22 22 24 26 31 38 42 47 51 56 060 065 070 075 082 082
3->4 30 32 34 36 40 46 52 80 85 90 95 100 105 110 120 134 134
2->1 08 08 08 08 08 08 08 08 08 08 08 008 008 008 008 008 035
3->2 14 14 14 15 17 19 22 23 26 29 32 034 037 041 046 053 065
4->3 20 20 22 23 26 30 34 39 44 51 61 076 080 085 090 100 105
#5
^^^ what he said
LS1 Edit has the same thing (which is what ARE is prolly using, but if you decide to buy your own software I'd recoomend HP Tuners of edit)
Right now I have my car set so that the car will never shift into OD below 55mph and the converter will only lock above 60
LS1 Edit has the same thing (which is what ARE is prolly using, but if you decide to buy your own software I'd recoomend HP Tuners of edit)
Right now I have my car set so that the car will never shift into OD below 55mph and the converter will only lock above 60
#6
Yep, shift MPH vs TPS%. A pretty good set of shift
settings (for a 3.23 F-body w/ 3000 converter) is
shown in this Excel file (for easy cut-n-paste):
http://home.cfl.rr.com/jimmyblue/PCM_Trans_20040823.xls
Your gears, converter, torque management preferences
etc. you'd have to adjust from there. And I had fiddled
some Engine TM params to make the Tranny TM work
cleaner, so on a 'Vette you might not even want to go
there, just use the shiftpoint related stuff and scale
for gears, rubber and redline.
settings (for a 3.23 F-body w/ 3000 converter) is
shown in this Excel file (for easy cut-n-paste):
http://home.cfl.rr.com/jimmyblue/PCM_Trans_20040823.xls
Your gears, converter, torque management preferences
etc. you'd have to adjust from there. And I had fiddled
some Engine TM params to make the Tranny TM work
cleaner, so on a 'Vette you might not even want to go
there, just use the shiftpoint related stuff and scale
for gears, rubber and redline.
#7
Yes it can be done.. like was said above, it will depend on your specific setup.. gears/tire diameter/and TC you have installed. Just now starting to get mine ironed as I found that the wrong tire diameter (26.9 vs actual 25.5) was input which was throwing everything off.
If I get a chance I will put up my actual settings in LS1 Edit for 3.90's/4000 Stall TC a little later.
If I get a chance I will put up my actual settings in LS1 Edit for 3.90's/4000 Stall TC a little later.
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#8
yah that xls is cool cept for not locking up in 3rd and a little rough with a 112lsa cam but a good guideline, you have to work on your tcc lockups as well to your liking. if you stare at the tables long enough and try variants you'll find the best feel and mpg,
#9
Originally Posted by samz28
if you stare at the tables long enough and try variants you'll find the best feel and mpg,
After some I started to "see" how the operating point moves around on the shift tables.
#10
yah make sure you stare at the TCC lockup tables too otherwise things will start to unlock and lock at wierd events. I prefer 4th to lockup when it engages, not a few mph later, otherwise it feels like its slipping.
#11
I wish he had looked harder in his editing software to find it! Although he showed me the trans section of his software and I too couldn't see where to fix it. Is it possible ARE is using some other type of software which doesn't allow the PTSP to be altered?
#12
maybe they just can't afford the good software. Ya know $500 hptuners. Some places are poor. (or incompetent).
go buy hptuners, do it yourself, they will never get it right if they dont know where the tables are lol.
go buy hptuners, do it yourself, they will never get it right if they dont know where the tables are lol.
#13
Originally Posted by Patman
My Corvettes tranny shifts into overdrive way too early for my liking (at part throttle), at only 40mph it'll do it, and it almost lugs the engine. And it takes a lot of throttle pressure to force a downshift at this point too.
Wouldn't this be the the "TCC Apply/Release Speed vs. TPS vs. Gear" ?
Bill