Cadillac ATS-V LF4 Tune E1

Purpose: Keep the throttle closed again after boost ramp up. Eliminate TCC slip. Study KR vs PE by going richer, so closer to tune c2.

Plan: Raise PE to 12.7 to try to address KR; no change to spark map for this run. Address TUTD shift RPM to try to enable automatic shift up in 1/2/3/4 not 5/6/7/8 so can hold those if needed for dyno. Adjust Turbo Knock Mass to raise desired boost level to try to close throttle. Study scanner with car to understand missing channels. Modify TCC pressure apply ramp to reduce TCC slip. Rescan.

Conditions: 76F, 29.83 baro, 87% humidity. SAE J1349 correction 1.0052575076413.

2nd gear 456.8 hp @ 5838 rpm / 458 torque @ 5126 RPM with 17.4 psi boost at peak hp
3rd gear 464.8 hp at 5320 rpm / 469.5 torque @ 4660 RPM; with 19.4 psi boost at peak hp
Corrected 3 gear: 467.2 hp / 471.9 lb-ft torque

Result: Still getting KR at WOT at 12.7:1 PE and current spark map.
Throttle opened at 5718 RPM in at 71 mph on one test, stayed closed in another. Desired boost just before 34.5, actual boost 34.4 psi. Then desired boost falls off and throttle opens. 2.3 degrees KR showing at that point. MAT 133F. Boost 19.1 psi. Cyl airmass 1.34. fine on boost max limit but pinched on knock airmass. So further knock airmass adjust?

Comparative results from last 3 scans on TCC slip error; still needs attention. For the gallery images, right-click then select view in new tab to see full page versions.

Missing parameters: Connected to vehicle, then repolled vehicle for parameters. Now everything is showing again. I think this happened after I changed from stable release to beta release, but beta release is seeing all the parameters after repolling.

Cadillac ATS-V Tune D2 Notes

Areas addressed: (1) Set AFR to 12.25 (2) spark advanced reduced 1-2 pts at WOT range of 1.16..1.32 4500-6500 to address KR (3) Boost max limit up 0.4 to allow more boost; (4) Pressure delta up 0.05 to build boost faster (5) boost knock airmass max 1.34 to allow more desired boost (6) TUTD set to autoshift 1/2/3/4 (speed) (7) airflow turbo base DC added 5 to 1.6/2500->3/6750 to allow a higher waste gate duty cycle (WGDC).

Current Conditions Settings Mostly Cloudy 86°F Feels Like: 89°F Humidity: 63% Wind: SSE 17 mph Barometer: 29.88 in Dew Point: 71°F. SAE  Air Correction Factor =   1.0176355313799041 J1349 AUG2004. Max 451.8 hp equates to 459.8 SAE J1349 hp. I remembered to test with a/c off, and in track mode. Hotter day than prior, at 87F vs 60F, hot car.

Thoughts: We are making more boost, but throttle is closing again. Absolute Boost 33 exceeded desired 32.7 as RPM climbed through 5157 RPM at 63 mph causing throttle to close even though pedal at 100%. Boost math exceeded 17.8 psi at that point; boost/vacuum 18.7 psi. Cylinder airmass 1.27 g, KR 1.1 degrees.

Boost math to 17 psi max in 1st gear, 18.1 psi in 2nd gear, 17.8 psi but then throttle closed in third gear. So good news we are seeing higher boost in lower gears. But more headroom needed in desired boost. Planning to add headroom in knock airmass table, or in max boost table; the manifold air temp broke over 160F on that run, which is where max boost is limited to 33.2 psi. Overall another run with the same tune but cooler air would be interesting.

Still some KR in the 1.16 to 1.32 pressure ratio, 4000 to 6000 rpm, even after I removed 2 degrees of spark here; although it responded to initial removal of 1/2 of the spark it didn’t respond to removal of the other 1/2. I changed the AFR at the same time, however. It may prefer less lean?

The transmission adjustment I made to add automatic shift to tap up / tap down (TUTD) mode was not successful. I changed TUTD vs speed but not vs RPM, which is set to 7K. I will add RPM limits to match pattern A or B for tune E.

Boost solenoid DC: I added 5% duty cycle from 1.16 to 1.32 pressure ratio, 2500 to 6750 in an attempt to get more boost earlier. The duty cycle hits 60% in 1st and 2nd and close in 3rd before the throttle opens. Appears to be working as intended but helped exacerbate the throttle closing.

Scanner note — switched to latest beta 4.11.1374. Several channels previously scanned successfully disappeared for some reason; not clear why.

Next steps: Raise PE to 12.7. Address TUTD shift RPM. Adjust Turbo Knock Mass to raise desired boost. No change to spark map. Re-initialize scanner with car to understand missing channels. Modify TCC pressure apply ramp to reduce TCC slip. Rescan.

Cadillac ATS-V engine run time delays

Did you know there are limits in your Cadillac ATS-V that are programmed based on engine run time (ERT)? ERT as in the amount of time the engine has been running that session.

The intercooler pump won’t start running for the first 10 seconds. Hard to make a lot of boost with no intercooler flow, but 10 seconds is a pretty short delay.

The intake cam and exhaust cam won’t vary their positions for the first 2 seconds (not much of a restriction there!) but again, don’t start the ATS-V then gun it and expect full performance.

If the engine coolant is VERY cold, under -4F, there is a fuel cut out after 5,200 RPM.