Blog Post: ATS-V Tune G – Throttle Opening, making torque

[Bruce Nunnally]

Tune G shows more torque production, but throttle opening everywhere.

Changes: AFR (E10 93 oct) 12.5 instead of 12.7. Changes to ramp parameters. Raised overboost limit. Driver demand redone using spreadsheet analysis. Peak torque and Max torque set to 12% over stock.

Conditions: Ambient air 84F; Baro SAE 28.05 Baro 29.23 Weather airport 29.81. Humidity 78F. Correction 1.0214 (29.81), so 480 ft-lbs of torque is 490.2 ft-lbs corrected.

Numbers: Hp 469.2 @ 5357 rpm, torque 480.6 @ 4448 rpm
corrected HP 479 @ 5357 rpm, torque 490.9 @ 4448 rpm.

The throttle closes when boost exceeds desired boost, and closes to the degree those differ. At and example point the throttle closes:

	Driver Demand Engine Torque (SAE)	109.0 %
	Boost Engine Torque Limit	472 lb·ft
	Final Throttle Torque Req	467 lb·ft
	Immediate Engine Torque Cmd	484 lb·ft
	Engine Torque	479 lb·ft
	Delivered Engine Torque	481 lb·ft
	Peak Engine Torque	561 lb·ft
	Maximum Engine Torque	472 lb·ft
	Predicted Engine Torque Cmd	525 lb·ft

torque results when throttle closes

The delivered engine torque of 481 lb ft exceeds the maximum engine torque at that point of 472 lb ft, but not the peak engine torque of 561 lb ft. In the tune, the “Maximum Engine torque limit” table shows 507 lb ft at that point. Max torque for lubrication is 501 ft lbs. So I am unclear why the Max Engine Torque is showing 472 lb ft.

View the full article