I have a 2007 G35x sedan and I am finally getting ready to make some performance improvements to it -- everything up to this point has been cosmetic: wheels, Eibach pro-kit, debadge. I have researching the forums for a few days now, so I don't make the ..."you idiot - that's posted in 27 other places!"... mistake. I digress...

I am trying to come up with a plan for my car to improve performance, without breaking the bank, and based on everything I have read I am thinking about the following...

1) Grounding kit - seems to be the best bang for the buck with improved throttle response and possible a very minor HP increase.
2) Intake - the Stillen G3 CAI with the ultra long tubes advertises 14hp gains at the wheels on sedans. No one else advertises anything close to that (that I've seen), Stillen is a trusted supplier (as far as I know), and they are on sale delivered through the end of the week for $474.
3) Tune - I keep hearing about custom & uprev tunes, though I do not know anyone in Kansas City that does it. Hypertech has the tuner that advertises an immediate 9hp gain while improving fuel efficiency.
4) Cat-back exhaust - no plan on this yet as I like the current sound and $1000-$1200 for 9hp does not sound like it would be worth it .

So here are my questions:
A) Is the grounding kit and Stillen CAI a good initial move?
B) Does anyone know a good tuner in the KC area or should I just do the Hypertech?
C) Am I totally missing it on the exhaust, in that it seems like a lot of money for not much HP (please keep in mind that I do not want my car to get much louder)?

I appreciate the thoughts from anyone who knows more about this stuff than me.

Thanks!

CT

 

Black betty grounding kit is great. Intake (if you search, you'll know ive tried almost every intake MINUS stillen gen 3), in my opinion, intakes are not worth it. Maybe the stillen gen 3 with exhaust and test pipes WITH tune will yield results. I have the hypertech but would like to get a custom Uprev tune next spring (i know of a place here in STL). hypertech made a difference though. Exhaust, i have stillen and I love it. it also made a difference in sound, looks and performance. fast intentions would be the only other one id consider but its more expensive.

to sum up,

grounding kit: black betty, yes
intake: no
tune: hypertech, yes. if modding heavily, id go custom Uprev.
Exhaust: stillen, yes

 

Just as a matter of proper course, I wouldn't recommend doing a tune until you have installed your final intake/exhaust choices. Any changes you make to them afterwards will probably necessitate a re-tune.

You probably know this, but I'll say it anyway; Don't take all the hp claims that manufacturers make at face value. Often times, while they may indeed make a few more hp at the mid to top end, at the bottom end or on an average they may actually cost you. A tune can make a world of difference toward maximizing it though.

I'm afraid that I'm not a great believer in the ground kits doing much if anything, so I'd have to say your best bang for the buck may be a package of Uprev w/tune, an intake and some HF cats, but again, don't do the tune until you have the complete package. Unfortunately, making more power in these cars is never on the cheap; Infiniti has taken all the easy gains already, so be prepared to commit to a certain threshold level of investment or you may end up being fully 2/3's invested for only 1/3 the potential gain available.

.02

 

The guys at Uprev told me there isn't much gain on our cars (stock) to be had with their software unless you have some mods done like exhaust or HFC or TP's. They still stand by the stillen intake if you have exhaust mods and the tune though. You do get the extra maps though like valet, low octane, econo (leaner), and performance though. Also you can have them move the rev limiter around and stuff like that which is fun.

I didn't see any tuners near you on the uprev site, so I think you might have to do an e-tune unless you drive to Union, MO which appears to be the closest place to you.