The following is why I don't believe that GM uses true torque sensing. They must use an algorithm based on WSS. It would be far too costly. :?

Binsfeld Engineering will be exhibiting at the EXFOR 2006 Show in Montreal, February 7-9, 2006.
Please stop by and see our torque measurement instruments: Booth 917.
PAPTAC EXFOR 2006, General Information: http://www.paptac.ca (Click on "Paperweek".)

Telemetry Instruments from Binsfeld Engineering
MEASURE Torque & Power ON DRIVE SHAFTS

STEP 1. Learn the Torque on the shaft using the TorqueTrak 9000 system.

For Temporary Installation, Test Measurements -

TorqueTrak 9000 telemetry system: http://www.binsfeld.com/tt9000.cfm

Fast & Easy Torque or Strain Measurements.

Portable. Fits any size shaft, any torque level. (Great for field work!)

Battery Powered RF Transmitter. (Data Transmission Distance ~ 20 feet.)

Price: $2,845.00 per system.

Delivery Leadtime: 2 weeks or less.

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STEP 2. Control the process using the TorqueTrak Revolution system.

a. Set High & Low Torque Limits or Alarms.

b. Use the roller torque signal as a feedback control signal to the drive.

For Permanent Installation, Continuous Monitoring & Control -

TorqueTrak Revolution System: http://www.binsfeld.com/ttrevolution.cfm
Continuous Output Data: Torque, Power, RPM and Shaft Direction.
Customized/machined to fit a particular shaft diameter.
Inductive Power & Inductive Data Transfer (No batteries. No wear surfaces.)
Price: $5,100.00 per system. (Up to 16"/406mm shaft diameter.)

Price premium will apply for shaft diameters larger than 16"/406mm.

Delivery Leadtime: 6 weeks or less.

Four independent output signals are standard:
1. Torque: 4-20 mA, scaleable.
2. Power: 4-20 mA, scaleable.
3. Shaft Speed/RPM: Frequency-based pulse indicator, mA.
4. Shaft Direction: Binary indicator, mA.
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Testimonials: http://www.binsfeld.com/testimonials.cfm
Applications: http://www.binsfeld.com/apply.cfm

I will be happy to help you with the application. Please feel free to contact me anytime for assistance.

Best Regards,
Bob Holden, Sales Manager

Binsfeld Engineering Inc.
4571 West MacFarlane Road
Maple City, MI 49664 USA

P: 231-334-4383
F: 231-334-4903
E: bob@binsfeld.com
W: http://www.binsfeld.com

You thought it was more than a smart engineer'* programming ability?

I figure it this way..they know a good range the car will do, therefore they can use, speed, throttle position, temps, KR etc etc etc to have their program do a pretty close analysis and take care of torque.