I have a 2008 G35xs with stillen pipes and K&N filters how much HP gain I might be up to and what else can I do for a gain (nothing to expensive?)

Also is HR springs better than eibach springs? Thinking about ordering some for a small lower-ing. (1.1").

 

You'll be lucky to have *brand new* stock performance...when the last time your spark plugs were changed, TB cleaned, MAF sensor, air filter, etc...? Once you can answer all these questions with "In the last year", Get an Osiris dyno tune, then we'll talk

 

Done in Jan 2012

 

All of them? I doubt it, most people don't do them. Most people also get terrible gas mileage and mediocre performance.

 

Got it from the dealer and had them change everything with warranties.

 

Did you change your fluids? All of them....

 

I highly doubt (know) they didnt clean the MAF sensor, TB, ect..but whatever it's your car. I don't really care, just trying to help you out.

 

Dont think that make too much of a differance. Going on 50k and if i drive nicely i get 27 on the highway which i did last week.

 

For some cars it won't, others it will...the only way to narrow down the performance robbers, and achieve the best mpg and performance (power) is to do all the little things that CAN affect performance, which 95% of people don't do.

Everyone wants to add a CAI to their G (lose power), but no one want to do the nitty gritty simple maintenance (gain power)....the definition of irony

 

Because 95% of people don't care about performance. Yeah change plugs ect..but you probably won't notice a difference at all especially if your car us under say 80K miles...if you are at 120K and have never done that stuff..then you may notice a difference..or not

 

Changing the spark plugs at 78k was the biggest performance change my G has seen, other than going FI. It was more clear power than my Kinetix plenum, ztube, k&n, or ResTPs. My plugs were toast, btw @ 78k. Fine with me though. It doesn't hurt my wallet when a fellow G gets 16mpg, or hurt my pride when I see someones dyno chart...yea, won't notice difference at all.

 

Doesn't seem like it's "fine" with you

 

Everything is up today. My plugs still have a while to go and the tran is sealed from what I have been told. Anything else I might or need to pay attention to? (FYI I try damn hard to take care of my car!)

 

You mentioned wanting to lower your G. H&Rs will drop your G quite a bit more than Eibach. If you want a mild drop look at Tanabe, Eibach, Tein H Tech (The S Techs are lower) and the new Swift springs that are just coming out.
Or better yet get coilovers and you can adjust the height exactly where you want.

 

Coils are so expensive that's the part that sucks. I am thinking springs, I don't want a drastic drop just don't want camber issues. So out of those you list are a good ride good mild drop and no camber issues. Thank you for your help to.