PCM tuning after gear change with A4
03-15-2019 | 09:07 PM
#1
PCM tuning after gear change with A4 So I just did a gear change from 3:23’s to 3:73’s. I knew the speedo would be off but the transmission shifting is now sluggish. This is the first gear swap I’ve done with an automatic. Will the different gearing do this to the transmission?
03-15-2019 | 10:10 PM
#2
Joined: Nov 2003
Posts: 6,166
Likes: 217
From: Wichita KS / Rancho San Diego
I don't recall any change in shift quality when I went from 2.73's to 3.42's prior to tuning. But you need to be tuned anyway, so the shift quality can be firmed up when that is done.
03-16-2019 | 08:56 AM
#4
Thanks for the help. I’ve done m6 gear swaps and never dealt with this. I don’t remember my converter locking up in drive before. This is all new to me. I guess the pcm thinking the car is going faster than it really is just throws everything off. Before the gear swap the transmission was fine.
03-16-2019 | 08:58 AM
#5
03-20-2019 | 08:02 PM
#6
11 Second Club
Joined: Dec 2016
Posts: 665
Likes: 4
There is a table for gear swap conversions to change shfit data in HP tuners I did it when I went from 4.10s to 3.42s HP tuner did adjust the shift data and made the speedo more accurate. You don't need a full tune for a gear swap.