Lt1 4l60e 3.42 rear end SHIFT TABLES

[yoheer]

3.23 orig vs bluecat normal shift tables @100% throttle
2nd - 36 vs 42
3rd - 73 vs 80
4th -126 vs 133
Won't it stuck in a gear with a rev limiter even with 3.23 gears?

[scooterwrench]

The idea is to keep your shift points in the torque range of your cam. You will have to determine what the RPM's are going to drop down to when it shifts and tailor the shifts so that that you're about 200 RPM's into the beginning of the torque range. You will need wheel speed,final drive ratio and tranny ratios to determine that. It's all about tuning to what [I]you[I]have in your car.
If you're banging the rev limiter before you reach the shift point then yes,it's not going to upshift until you back off the throttle.

[yoheer]

Im just trying to say that tables generated for a stock car by bluecat differ from original tables.

[scooterwrench]

Of course they do. That .bin was probably set up for another application that worked good for his or her desired outcome. You are going to have to retune it for yours. Considerate a starting point. Save it,copy it and tune the copy.

[yoheer]

And bluecat 3.42 tables are almost the same as original 3.23 :)

[dave w]

And bluecat 3.42 tables are almost the same as original 3.23 :)

BlueCats is a very helpful tool intended for HP Tuners likely for OBD2 vehicles. Excel is helpful transposing the BlueCat shift tables for OBD1.

Often starting with a factory .bin file that has the 3.42 gear ratio is a good plan.

I use TunerCats for OBD2, not HP Tuners.

For an experiment, I changed the gear ratio of a 1996 Buick Roadmaster to 3.42 gears. TunerCats changed a total of 25 parameters. The .txt file of the changes is attached. Likely a factory .bin file with 3.42 gears will NOT require all 25 changes listed in the attached .txt file (assuming same tire size)

96 Roadmaster 01.jpg

96 Roadmaster 02.JPG

96 Roadmaster 03.JPG

96 Roadmaster 04.JPG

[lionelhutz]

Saying 25 parameters is a little misleading because for every table listed it would have scaled every data point in that table. 100's of actual data points get changed.

Did you check that you had the RPM and tire size/diameter correct in the Engine/Drivetrain box in Bluecat? That can make a big difference.

Remember that Bluecat doesn't duplicate stock tables, it uses calculations to create new shift curves.

Whatever you do, don't go changing the maximum line pressure scalar unlike what you might run into reading how to tune your transmission on the internet. The PCM is coming up with a number between 0-96 and then using that to look up the force motor current in the force motor current tables. Since 96 is the highest column, you want to leave it at 96 to limit the calculation to 96.