07 Cadillac STS 4.6 Northstar

[Pjotr9]

Hello everybody,
I have Cadillac STS 07 4x4 with 4.6L Northstar engine, changed cold air intake and Gibson SS exhaust. I'm looking for way how to get some extra hp and improve response/behaviour of the car.

So far I have done more functional modifications like increasing top-speed limit, decrease RPM when air-condition turns off and switch transmission into sport-shifting mode for all the time.

Now I would like to go deeper and add some extra hp and make shifting faster but I'm not comfortable with "blind" modifications (I don't feel so skilled in this.) So I tried to make some research around web. Unfortunately there is nothing about STS Northstar ECU modification and Google brought me back to this forum to PGA2B's topic about STS-V. I went through "tune" which is posted there and I know that I can't compare or use it for my "tune". However, I'm curious about "non-engine" modification - especially about different values in transmission part and if it's safe to use them.


Can you please share some experience/tips how to increase hp on this engine? At the same time I will be thankful for any tips how to improve overall performance.

Thanks and have a nice day

I'm including my actual tune:
CadillacSTS - po uprave.hpt
..and original:
CadillacSTS.hpt

[Pjotr9]

Anybody?

[SultanHassanMasTuning]

didnt know it was support, let me see the file...

[Pjotr9]

didnt know it was support, let me see the file...

Thanks for watch. Did you find something interesting?

[mowton]

Very rudimentary shift feel can be modified in the Inertia Factor Upshift table. It contains values 1-9 with 1 being softest and 9 being firmest. You can add a couple of points to area's that the shift feels too soft. Also you could increase the shift pressure levels a bit (say 5-10%) and max pressure to 290 psi to firm up the shifts. The A6 is a complicated tranny based on several interacting shift time tables and torque based values and requires a lot of knowledge or you can end up with more trouble than power.

As far as HP, you will have to install a wideband so you can zero in the WOT Air, Fuel and Spark. You can go the "e-mail tune" route but I just don't think they are a safe way to go nor a huge bang for the buck. Normal area's to adjust are the IAT/ECT timing adjustment tables. Shift the table from 95 to say 122 IAT and cut the ECT 212 column in half.

Provide a few logs and maybe someone can recommend some area's of improvement.

In an Auto, tranny tuning will most times provide the most "seat of the pants" increase.

Ed M