Lightweight flywheel...lighter weight accessories (such as billet tensioners/idlers/crank pulley) would also make the motor rev freer...a lot of what people overlook is the valvetrain...lighter lifters, stronger/lighter valvesprings, titanium retainers and such...all contribute a large amount.
If you've ever been in or driven a 3800, you'd know how laggy they are...
Swapping out the rockers for lightweight rollers, cromoly pushrods, Titanium retainers, upgraded springs, and a balanced rotating assembly made for a HUGE difference in the way the car picked up RPM's...and jsut the overall responsiveness of it all...was awesome.
Just something to think about.
The Racekar - SOLD!
2007 Cashmere Metallic Chevy Cobalt LT Sedan
2010 VR Cobalt 2LT Sedan
Debadged, ZZP Intake, Custom 2.5" Exhaust/Borla Pro XS, FE5 Bidnez with KSport Springs.
Previously dumped on BC Xtreme Low's...RIP LOWLYFE :(