Originally Posted by shadow191
What is the nature of the motor that causes this? The throttle body is electronic, not cable so they could program it just about any way they want. As I posted before, my other car is an Infiniti FX. N/A 3.5L V6 w/ electronic throttle body as well (no ITB's either). Incredibly responsive and linear throttle response. Tap on the pedal a little, car moves a little. You know exactly what is going on. On the 335, it's dip into the throttle...nothing happens...step on it harder, car jerkily takes off. There's almost no relation between your foot and the throttle response. It's most annoying when you slow down for a light and then get back on the gas before coming to a full stop. Then you have to deal with the transmission lag and throttle lag.
Numerous factors. Bigggest factor of your specific comparison would be turbo vs NA. Taking turbo lag out of the equation for a moment, on the N54 air needs to get sucked in through small inlet tubes (2), pass through the compressor wheel, join the seperate air channels in through an intercooler biggest restriction right here), then up through a charge pipe that have diverter valves open at idle/until the TB opens and creates pressure in the intake manifold for the DV's to close. All of this signifigantly reduces throttle response as you would be used to in your comparo. All the NA motor has to do is open the TB and air goes straight into the combustion chamber. Adding turbo lag back into the equation, it makes it even worse.
Also, head design (N54's head flows very poor in comparison to say the E46 M3's S54), intake manifold design, and obviously electronic throttle tuning plays an important roll in throttle response.
This car is a DI motor (I don't think that Infinity motor is) so carbon caked on top of the intake valves will add to the delay you feel, among gearing differences as you mentioned (That's more how fast power can be put to the ground however)