So I got a 2010 G37 4-door for my wife, and recently installed a Stillen Gen 3. She likes the gains felt, but now is thinking about what else she can do. She would like to get a little more power but try to help her gas mileage as well.

I have heard about getting a chip for it, and I know you can also tune it. I have also had someone suggest just flashing the ECU. I live in Houston, and have heard JTran does great work if I want to have it tuned.

She is a professional who has to go to schools for meetings, so doing headers and exhaust will make it too loud.

I would appreciate any feedback/suggestions on options. I'm not sure what chip to look for if I go that route.

 

Avoid the chip route and go with a UpRev or Ecutek tune. Yes, go with JTran to tune your car. My friend vouches for them constantly and they've done tons of tunes on nissan's/infiniti's in the Houston area.

But if she only has intakes installed, she won't get very much gains with a tune. Maybe look into getting a Fast Intentions RHFC, before getting a tune.

 

Not all exhauts will make the car that loud, systems like Fast Intentions yield some solid gains but keep the tone at a pretty tame level unless at WOT.

 

If the car isn't AWD or manual the best bang for buck "power adder" is changing the final gear ratio.

As the owner of a FI exhaust I would have to disagree about the exhaust dB levels. Yes there are exhaust that are not much, if at all louder than stock but FI isn't one of them.

You can invest in upper and lower intake manifolds, cams, high flow cats and a subtle exhaust and a tune (not specifically in that order). Those should yield pretty good results as there's not much else you can do other than forced induction after that point.

Happy modding.

 

I'd recommend these five mods given your apparent goals.

1. Fast intentions resonated high flow cats. Good power added, high quality and very little change in sound
2. M370 or Z1 upper plenum
3. Hotchkiss sway bars
4. Swift springs mild drop
5. Ecutek dyno tune

I think that will set you back about 3500.00 total parts installed and give you a noticeable bump in power increase fuel mileage is likely albeit not by a lot and your car will handle worlds better and look better too.

 

Sways is something I always recommend. Doesn't help on the power side but as upscale said, WORLDS of difference in handling.