[thePill]

Originally Posted by SUX2BU

It says max torque capacity is 500Nm. Maybe my math is wrong, but doesn't that convert to 369 ft lbs? Why else would they use the Getrag for the GT and the Tremec for the GT500?

Your math is correct, 500Nm is only 369lb ft of torque but you are missing a very important factor in transmission ratings.. and that is the weight at which that transmission achieves that rating. If the same transmission were to be rated with a GVWR of 4600lbs (Mustang GTs GVWR), the 369lb ft maximum torque rating advertised would be doubled. The transmission requires force and resistance to determine the torque rating. Without resistance, the torque rating on a transmission would be infinite. Force would be the power generated from the engine and resistance would be the weight and traction of the tires. Since traction is difficult to simulate, weight (mostly because of towing capacity) is very important when transmissions are rated. This is why you see 9 and 10 second 5.0s on a stock transmission, because the transmission was rated with 10,000lbs of resistance, at that weight, the transmissions torque rating would be very low (370lb ft) but at the Mustangs actual curb weight, the transmission would be capable of 600-700lb ft of torque unless the car had tires on it that allowed maximum traction. After awhile the transmission would eventually fail.

As for Tremec (we will use the TR6060), Tremec rates their transmission at exactly or very close to the torque and weight of the specific vehicle it is made for. For example, the MG9 in the CTS-V is rated at 560lb ft at a 4250lb vehicle weight (not GVWR but curb weight). The M10 found in the Camaro SS is rated at 430lb ft at 3900lbs. The only exception would be all Corvette transmissions are rated at 4000lbs even at the exact engine torque rating, I do not know why this is done.

Why doesn’t the GT500 use the Getrag? Because the 5.4 is on its last leg and will be discontinued shortly. The Getrag equipped 5.0 will take the place to the 5.4 and Tremec. Why spend the money on R&D?

Besides, it is very possible that Ford and Tremec have a contract…