I currently have the following modifications done to my 2013 G37 sedan RWD...

Mishimoto intake tubes
R2c drop ins
Throttle body coolant bypass
Grounding kit
Tanabe lowering springs
Godspeed sway bars
Custom 2" x pipe that expands to 2.25" straight exhaust

I have the stock cats still in place and plan on getting the car tuned soon. At this point is it really worth putting off the tune to install FI 2.25" resonated test pipes (no hfc) or would I be happier with the dyno tune? If we are talking a gain of less than 10whp/10wtq for swapping to resonated test pipes then I think it would be best to just tune it and drop my 3.69 diff in. I am also concerned with the volume increase/drone possibly being too much.

Have I hit that point of diminishing returns as far as modifications are concerned?

If I forgo the FI test pipes I would use the money to finish the differential install and upgrade from uprev to ecutek.

 

You still need coil-overs.

 

Not particularly. Car will never be tracked and I am totally satisfied with the handling at this point.

 

I have art pipes v3 for sale.
Might as well get the most power possible.

 

Great idea except I couldn't sleep right knowing the piping goes from 2" at head to 2.5" at art pipes then to 2" at x pipe then 2.25" at x back. Too much turbulence

 

Wait to tune until you install the test pipes. It'll change things enough that you could damage your engine if you slap them on after a tune and drive around in anger (WOT).

 

Oh I wouldn't tune then do test pipes, give more credit than that lol.

My tuner basically suggested to forgo test pipes and just continue with my current setup. I am however thinking about the z1 manifold now before the tune.

 

Z1 intake manifold is a waste of time. Test pipes consistently produce the largest gains on our cars. If your car already isn't too loud, do test pipes.

 

From what I was reading on the 370 forum, the z1 manifold showed some slight improvements over stock. It isn't really all that expensive either and I want all my mods to be done prior to tuning. I figured that mod wouldn't really make the car any louder as well, win win.

 

I was told by a person of high repute in the Nissan world not to waste my time and I trust him. I was in the same boat. Doesn't cost a lot. He basically said it wasn't worth it.

 

I'm sure you're correct. I think I'm just going to stick with the catback, intake and tune setup. The gears should make enough difference to keep me smiling