I guess its good to have a pair of spare K&N air filters. I will use em when I go California Speedway or something... A 1 minute easy reversible mod which adds 5+ hp, not too shabby.
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2008 G35 journey5at ivory/stone+prem&sportpkg.

 

I installed a K&N filter in my '95 240SX... I had the filter for ~9 years and never had a problem. I even inspected my throttle body and there was no dirt whatsoever. I think part of the problem is that people clean their K&N filter way too often. They filter better the dirtier they get (with only a slight compromise in air flow). I typically cleaned mine only every 50K miles. I definetely did feel a slight increase in power compared to the OEM filter and there WAS a measurable improvement in gas mileage as well. By the way, the exact same filter is now in my '06 G coupe (exact replacement). Not bad for a $60 investment. Over oiling your filter might cause the MAFS to malfunction, but I personally know of no one who ever had that problem (+ you would really need to over do it IMO).

 

And the saga continues.. there seems to be two different camps regarding this filter thing.. I dont know what to think anymore. lol

Im planning on keep my G for a while.. im thinkin at least.. 7-8 yrs. Thus, its probably not wise for me to do any kind of mod that could "potentially" damage my car in the long run.

Thats why im leaning on just replacing the catback system rather than intakes. UNLESS, if there was unequivocal proof that these aftermarket filters will not cause me future problems..DOMO

 

You are completely insane. The drop in K&N's DO NOT give you 5+ hp! The air from the Stillen Long tube intakes move the same temperature air into the intake manifold as do the stock filters. They should take in more dirt as they have more surface area.

 

actually it might. my dynos(not g35 though) did.. but only in the very higher limits like 6k and up. I'd be worried about metallic tubes as they may allow more heat to get through to the intake air. We already have a pretty good RAM air system, but there are always people who have the need to mod something regardless of how silly it is. Even exhaust maybe kinda silly for a NA car. NA cars do need some back pressure and its silly if you lose power and cant pass emissions. I'd be careful about hp claims. You should consider the whole area under the dyno curve instead of the tiny spike in one area while it loses everywhere else. If you want best times at the 1/4 mile, just dont even use air filter at all.

 

I was specifically speaking of our 2k7+ G35's. I have also seen 5-6hp gains from other vehicles with K&N drop in filters. Another point I was trying to make is there is no way anyone can tell a 5hp difference. The gains some are trying to report via butt dyno, could lead others to think they will notice huge gains. This simply is not the case.

 

two questions:
1) what is NA car?
2) Tell me about "need some back pressure" for the exhaust?

 

So!! Aftermarket will Gain HP or Loose more HP,Any advice?

 

prolly the truest comment in all of this thread.
metallic tube will add couple of degrees to intake temp.
exhaust dont do much for n/a vq.
and k+n do clean better the longer they have been in.

 

but thats the same for all dirty filters.. they do clean better... just less air through :P My problem is that you can't thoroughly clean the k&n. Against the light the darker spots seem to let less light through compared to the edges. If those dark spots are where it matters most, I'd rather have a new stock filter.

NA means normally aspirated..i.e. non-turboed/supercharged.

As for the back pressure thingy... u're better off reading tech articles from google search.

 

oh ok.. gotcha! thanks for letting me know.

 

this thread is a joke.

 

The short answer is that cars can lose a little bit of torque with no back pressure from an open exhaust (no pipes or mufflers).


The really short answer for the 2007 G35 sedan is that the factory intake and exhaust systems both flow very well, so unless you highly modify your car, you won't need to change them. And if you do change them, it'll only net very small hp gains if any at all.


Another "problem" with aftermarket exhaust and intakes on the modern cars with so many sensors and computer controls is that when you change ANYTHING, the computer doesn't necessarily like it and you'll get worse fuel economy and power. The computers on some cars are too sensitive to change.

 

hmmm... im not liking the sound of getting worst fuel economy... its bad enough already. lol but really, im not interested in HP gains.. its really just the sound im interested in. But of course, if there was HP gains, its welcomed with open arms.

thx for the info.

 

6+ months with the K&N - I have noticed a negligible change in fuel economy.

I have logged every fill up for this car with the odometer noted.

Put filters in at 13000 miles; Average mileage at that point was 17.33 mpg

Average mileage for the past 5000 miles with the K&N filters - 17.11 mpg.

That 1.26% difference can easily be attributed to the fact that all of the *%&$! gas stations in my area now use "no more than 10% ethanol". I would only fill with 0% ethanol if I could. It used to be that only Racetrack and Hess had the 10% dilution, but now I am hard pressed to find any stations that don't do it. I find I get worse mileage with 10% ethanol.