I got a G35 coupe 03 automatic

I did the the custom remap, k&N typhoon air intake, megan straight test pipes, y-pipe, invidia N1 catback exhaust, skunk2 1/2 engine Spacer... and im waiting for my transgo valve upgrade body kit and for obx crank underdrive pulley (lightweight),

but what do u advice next for better performance? should i remove some weight from the car?

 

You've got pretty much all the bolt-ons covered. Weight savings won't translate into much of a power/performance gain so your only 2 options left are Nitrous or going FI. You could squeeze a little more HP by building your motor, cams etc, but that route isn't worth the cost vs gains.

 

What do u mean by FI?? I was thinking about the following: cams, or intake manifolds like Kinetix SSV Infiniti G35 Intake Manifolds or Skunk2 Racing Intake Manifolds, or engine torque damper, throttle body spacers... dunno so give me more ideas

 

Forced Induction, things like supercharged, single turbo or twin turbo.

 

IP nailed it. Cams will make a little more power, but again probably not worth the cost for minimal gains. Don't waste your time in any aftermarket plenums/intake manifolds. They might look pretty but a 5/16" plenum spacer from Motordyne will give you proven gains for a small cost ~$200. Torque dampener, throttle body spacers, and underdrive pulleys generate a lot of debate but the general consensus on here is they're worthless for gains.

Trust me when I tell you that the only other non-forced induction option is to pull your engine and rebuild the motor and even then you'll be lucky to break the 300whp barrier.

Other than that you're SOL, sorry.

 

what about headers 3-1? or long tube? i want to keep it naturally aspirated for the time because my budget doest allow unless a used turbo... but my goal is to show a good difference between stock Gs and my G... plus i will make a better decision after i install the transgo valve body upgrade kit... i bought it and it will arrive soon... a friend of mine told me it will make a big difference in driving and much more fun...