The later short runner intake was a compromise, it lacks volume and was designed to fit under the hood. With the single throttle body design and short runners it is better for driveability and peak power, but the long runner Gen 1-2 manifold makes much more torque across the powerband.
When we were selling Vipers at the dealer years back, we would sell them on Friday and they would be in the bodyshop on Monday. People were not used to the torque. As the Viper evolved, the power delivery was softened up and moved higher in the rpm band. Thats why the Gen 4-5's feel a bit fluffy down low. The new drive by wire cars limit throttle angle in the lower gears (torque management).
