I have a bunch of questions! I did a gear swap from a 2.59 to 3.54. Last night I recalibrated the speedometer. I am using Tunercat. When I downloaded the data on my pcm Tunercat said that I had a 3.07 axle ratio but my rpo code sheet says I had a GM1(2.59)! Is this weird? I went ahead and changed the values, I put in a 3.54 axle ratio and changed my tire size to compensate for the new 315s I put on. I took the car out on the highway today and checked my odometer with the mile markers on the highway. My speedometer and odometer are perfect! Now I have a problem with the shift points. Aboatguy has been very generous with his help. He told me to multiply my shift points by .73 to get me in the ball park, because his gear swap was close to mine. I think he did a 3.45 swap. How did he come up with this, just out of curiosity? I was wondering if anyone has done a 2.59 to 3.54 swap and how they did there shift points? On my tunercat program do I need to multiply this to all of the shift tables (normal shift points, performance shift points, kick down shift points, and I think there is one more)? My vette is a '95 a4, only thing I have done to it besides the change in gears and tires is a 3" B&B exhaust, is there anything else I can use this tuner program for besides the shift point corrections on my stock vette? Does someone have an exact number I need to multiply by because if the .73 just puts me in the ball park I don't know what to do after that? Sorry for all the noobe questions and thanks again Aboatguy and thanks to everyone else in advance!

 

I multiplied .73 to all of my shift tables. The car is shifting pretty good now. Under wide open throttle at what RPM should it shift at? Mine is shifting 5600 RPM I think. I am not sure I am going to have to pay more attention. I haven't drove the car a lot since I started working on the shift points. I know it is shifting well into the redline on the tach. Can someone please help?