a4 shift question, please help.
Thread Starter
Instructor
Joined: Jan 2003
Posts: 159
Likes: 0
From: Day Dreamin MI
a4 shift question, please help.
I have a 98 vert with an a4. I recently put a 3.42 in it. A local shop did the install and reprogram. After a break in period, I attempted a top end run.
When I started from a dead stop, WOT, the car will not make the 3 to 4 shift. It will travel well into redline. I attemted the feat 3 times and got the same result. As soon as I let off the car shifts to 4.
However, traveling at highway speed and then hitting WOT, the car downshifts to 3, accellerates and then shifts to 4 correctly.
In addition, the 1 to 2 shift bangs at low rpm. If the rpms are mid to high then the 1 to 2 shift is fine.
Wondering what might cause this situation.
The local shop stated that the only thing reprogramed was an increase in line pressure, and fan temperature. The shop owner is very willing to reprogram the car at no cost, however, I don't think that he understands what is causing the problem.
Any suggestions would be greatly appreciated.
When I started from a dead stop, WOT, the car will not make the 3 to 4 shift. It will travel well into redline. I attemted the feat 3 times and got the same result. As soon as I let off the car shifts to 4.
However, traveling at highway speed and then hitting WOT, the car downshifts to 3, accellerates and then shifts to 4 correctly.
In addition, the 1 to 2 shift bangs at low rpm. If the rpms are mid to high then the 1 to 2 shift is fine.
Wondering what might cause this situation.
The local shop stated that the only thing reprogramed was an increase in line pressure, and fan temperature. The shop owner is very willing to reprogram the car at no cost, however, I don't think that he understands what is causing the problem.
Any suggestions would be greatly appreciated.
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
Re: a4 shift question, please help. (emptypockets)
Sounds like shift points need to be tweaked...LS1 edit will do both MPH & RPM so it sounds like a simple tuning issue. Good luck! :cheers:
Burning Brakes
Joined: Feb 2004
Posts: 1,108
Likes: 0
From: over the water Cali
Re: a4 shift question, please help. (emptypockets)
:iagree:
If you have autotap(EFI6Live) you can monitor he run and watch the shift points and have some one edit the trans for you. The rpm shift is stock set at 6000 in 1st and 5900 in 2nd and 3rd but will only due this if the min. Mph is met. This needs to be adjusted and if it has already been adjusted you may have a little more slip in your components at WOT froma dead start verses from a roll. The best thing to due is set the Mph to a slightly low level and let the computer shift at the correct rpm at all times. One other thing is wheel spin can cause all kinds off problems with Traction control and correct computer shifting. A run from last week showed me at 6500 rpm at 2 sec from a dead stop but my Mph was only 35-37 real and 43 on the speedo. This cause a rapid ramp up in rpm faster than the tranny could shift and it hit redline for a faction of a second. I hope this helps a little. :D
If you have autotap(EFI6Live) you can monitor he run and watch the shift points and have some one edit the trans for you. The rpm shift is stock set at 6000 in 1st and 5900 in 2nd and 3rd but will only due this if the min. Mph is met. This needs to be adjusted and if it has already been adjusted you may have a little more slip in your components at WOT froma dead start verses from a roll. The best thing to due is set the Mph to a slightly low level and let the computer shift at the correct rpm at all times. One other thing is wheel spin can cause all kinds off problems with Traction control and correct computer shifting. A run from last week showed me at 6500 rpm at 2 sec from a dead stop but my Mph was only 35-37 real and 43 on the speedo. This cause a rapid ramp up in rpm faster than the tranny could shift and it hit redline for a faction of a second. I hope this helps a little. :D
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
Re: a4 shift question, please help. (emptypockets)
Yea sounds like shift points need tweaking.. As for the 1-2 bang.. you said they raised the line pressure.. this would cause a harder 1-2 shift.. I may have missed it but what was the purpose for raising the line pressure.. adding the gear and raising line pressure can make a 1-2 shift feel harsh..
-Rick
-Rick
Heel & Toe
Joined: Aug 2003
Posts: 20
Likes: 0
From: Foothill Ranch CA
Re: a4 shift question, please help. (emptypockets)
The predator can also be used to solve your problem. I made the same modification several months ago (A4 3.42 from 2.73) and had a bunch of shift issues at wide open throttle and minimum throttle. I also had a problem with the 1 to 2 shift being very harsh at minimum throttle. In short, one of the guys responding before me hit it just right, the computer needs both rpm and mph shift data adjustments after changing gears. My car now runs and shifts very well, with some "tweaking" of the mph & rpm shift point settings. I am not familiar with LS1 Edit personally, but one of the other respondents said it will work, if you have someone nearby who can properly use it. Good luck, hope this helps. :)
