'05 Sedan 5AT. When i'm accelerating at around half throttle - especially in 2nd gear - the motor really comes alive at 3500rpms. Almost like my old 280zx turbo when it finally spooled up. Anyone else notice this change in the power delivery? Maybe this is where the "variable exhaust" plumbing kicks in for the 05's? I don't notice it as much under full throttle

Also, I used to want the coupe mid-pipe...but now with 6500mi's and a z-tube, i think it's loud enough for me. Not so much when it's cold, but after about 10min of driving the stock exhaust is more prominent and will even get a little drone when idling in traffic between 700 and 1500rpm - especially with the windows down. When i drive the '04 loaners I don't notice that...seem a little quieter in general.

 

The G's engine is a high winder, and is happiest at higher rpm's. Like you said, there is a variable exhaust on the Sedan which would help low end torque and transition (at about 3500) to high rpm power.
C.

 

You're exactly right ... I'm no engineer, so I'll let the smart guys here explain variable exhaust, timing, and dual overhead cams To me, the sound of the 05 sedan is great, a little meaner than the 04s, with just a little hint of the coupe's signature wail.