Just Installed K&N Filters
 

Hi all. Just dropped in 2 K&N filters for my G-unit. Went for a test drive, engine sounds a bit deeper, more responsive, and a tiny bit faster. Overall I feel a small difference which I'm happy with.

Air suction sound is same as before, not louder and no whistle sound... maybe after the filters break-in few hundred miles. Hopefully the K&N filters will help with gas mileage.
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2008 G35 journey5AT ivory/stone+prem&sportpkg.

They will certainly help bring in more dirt into your oil.

And other intake filters won't?

I believe K&N actually supplies filters for some intake companies.

It's the other way around for me. When I put the OEM's back on to clean the drop ins, the car felt more powerful. Probably just placebo.

As for the sound, I hear the whistle a bit louder and the growl is tad bit louder under WOT. It could be just me though.

Anyways, :biggthumpup:

^It is just your car cuz it's special! :biggthumpup:

Does K&N filter really work tho'? I mean... for that price... I don't know. :(

Really tough to say without a dyno. On a 1g turbo DSM, the stock filter is cone shaped. Removing the air can and adding a K+N is good for about 10hp. Now, that is turbo car, I would suspect a K+N drop in would net you 1hp...maybe.

None of the intake systems currently available for the G35 will net you any negligible power increase. Infiniti did a great job in desigining the stock air boxes. Cobb Tuning recently documented this on their blog. I bought these filters as replacement for my stock filter because I can wash them when they are dirty. Easy math for me $12X 2 every 7500-10000 miles or $85.00 unlimited life span.

Right, and that's fine. I was just posting some info on power increases. A lifetime filter is a good thing.

I haven't looked, but is the G35 a MAS or MAP sensor setup? If we have MAS, the oil from the K+N oil can coat the MAS and reduce efficiency.

the hard truth is that you dont really save anything and unless u race a lot, k&n isnt going to do anything for u except for a tiny sound effect.

I'm not sure if it works or not, but knowing I won't need anymore filters is a always good.

I got them as a gift from my friends anyways. :BOOBIES:

The K&N panel filters may not "work" by giving you more HP, but you will save money in the long run for not having to replace your air filter...these ones you just clean, re-oil, let them dry, and them put them back in. in the long run you may see some savings.

they are more effective in other ways such as trapping more dirt due to their superior construction. if you got yourself a set of intake tubes without resonators for a louder sound, and then these panel filters i think it would be a great combo.

This is completely false, k&n's trap significantly less dirt than an OEM filter

You are correct.. OEM filters do a better job of trapping debris and dirt than K&N.

And as for the sound, drop in K&Ns are not going to give you any sound increase to my knowledge. I've tried the drop ins in my Honda and I did not hear anything different.. but who knows it might b different on the VQ motor..:dunno:

I agree OEM filters trap dirt better than K&N. When you look at K&N filter under a light there are lots of tiny open holes...

Would be nice if I can run these filters on some car for 1000 miles then put them in my car, K&N filters works better as it ages.

I've used K&N's for years and never had a problem. I just installed drop in panels and have felt no HP/quickness difference.

I've been very disappointing in my MPG since I bought this car (14,500 miles so far). 16.9 to 17.1 average pre K&N. First two fillup's averaged 18.3 and 17.8 repectively (currently at half a tank on second fill up since K&N) on the 17.8 mpg tank. Not much but it did actually increase a tiny bit.

Going off on a tangent here...Anyway, yesterday I replaced my old air filters w/new OEM ones after recently hitting 30k miles (Man, were the old ones DIRTY!!). Going to work this morning I definitely got a small MPG bump (normal driving/freeway condition) according to the trip computer. It'd be safe to say that performance/responsiveness has been restored, too, but my butt dyno isn't as sensitive as some of yours. =)

Let's assume the K&N filters offer exactly the same performance as OEM filters.

A pair of OEM filters = ~$20. When it's time to replace, simply throw away the old ones and pop in the new ones.


A pair of K&N filters = ~$100. When it's time to recharge the filters you need to buy a K&N recharge kit (~$10; will last numerous recharges) and spend the time cleaning, re-oiling, and allowing the K&N's to dry.

According to the manual, you're supposed to change the filters every 30K miles. This means it'll take you AT LEAST 150K miles to justify a cost savings by purchasing K&N filters.

your gas mileage increase might be several factors, but i'm not convinced k&n will make much difference. when i ran dynos on the various filters/intakes, if what u said was true, then I would have seen more power sooner and everywhere. What I've seen where k&n did make power was 6k rpm and up... and that was on a turbo car, which makes sense because if u dont really stomp on the gas and run up the rpm, your car has plenty from air the stock filters.

In my experience, it was not worth my time cleaning the oily silcone residues, and trying hard to clean spots on the filter that can never get clean enough, not having a car while that thing dries, worrying about over oiling, etc. After about 3 cleanings, your filter wont be consistently clean everywhere which I a brand new stock filter will do its job better and flow air better at the spots where it counts most.

and yes, the k&n oil did mess up my MAF.

Just went for another test drive. Today I'm refreshed, was tired late last night after installing.

Man there is definatley difference. When I step on the gas the torque kicks in harder, the exhaust bit more deeper and humming. The air filters "unlock" G's power somewhat, maybe 5 to 8 hp gain in my opinion.

BTW i ordered my filters from autoanything.com, it was cool, i ordered them on monday and got em tuesday directly from K&N company in Riverside, CA, with K&N tape seal and all, I guess they route their to K&N directly.. Previously I went to Kragen, autozone, pepboys, they wanted $60 per filter which is rip and above retail price and they have to order it and you have to wait 3-5 days.
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2008 G35 journey5AT ivory/stone+prem&sportpkg.(k&n air filters)

It's worth it to me to have K&N's just so everytime I get an oil change they don't try to hit me up to replace my "dirty" air filters. That drives me crazy. I have 14,500 miles and they have told me twice I needed to replace them.

Oh, BTW I just dyno's. K&N's by themself took it from 270HP at rear wheels to 389HP, not bad for $100.00 I then pulled a 10.99 at the drag strip. :rolleyes: ;)

seriously though .7 to 1.2 MPG is a 5% increase which is pretty good. I have tried everything and never gotten better than 17.1 MPG around town ever. It has definitiely increased, but in the grand scheme of things it's pretty small.

isn't the air filter under warranty? because from what I remember....when I had my 2005 sedan....They change the air filter for me for free. Maybe its just in Canada.

no wear and tear items are under warranty.

No, not covered under warranty...maybe they just included it in the maintenance package?

I think it's the placebo effect. Nobody on earth can sense a 1-3hp/tq increase. There is no way in hell the drop in K&N's give 5-8hp. I can guarantee however that if you have your oil analyzed you'll see a significant jump in silicone. Most cars have one filter and silicone numbers jump up. I can't imagine what 2 will do. When this happens, it lowers the ability to go long oil change intervals. So the K&N filters actually cost you money instead of saving money.

I want to share my experience:

1. I installed the stillen intakes. Nice growl.
2. Installed the FI Exhaust, a lot of growl :-)).
3. Car start to have problems in idle.
4. Remove Stillen intakes and put stock boxes. I lose high end growl and a little power,really like low en torque now.
5. Planing on testing KN on stock boxes.

I'm very impressed with K&N filters.:) I was somewhat skeptical to begin with. From past experience with drop-ins for civics and tacomas, no difference... perhaps cuz they are low horsepower cars. But they have made a pretty damn good difference for the G35, overall the engine is more hyper and eager, the throttle hugs and responses noticeable better.

The engine and exhaust sounds better too. The psssst turbo air sounds between gears is becoming louder and starting to have a high pitch noise. No noticeable gas mileage difference yet...

I dont recommend wash and reoiling k&n filters cuz washing(the drying part) will screw up the cotton unless you dry the cotton in a dark vented room with a humidifier. I plan to do dust tapping every few thousand miles and buy another set of k&n at 50K miles.
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2008 G35 journey5at ivory/stone+prem&sportpkg(k&n airfilters)

Remove you're air filters completely. Dyno car. You'll likely gain 3hp tops.

So, do you really think swapping one air filter for another will make a difference in power or fuel economy?

It won't.

The only way your car will gain significant power or fuel economy is from a complete intake swap..... IF your stock intake is restrictive.

Ours isn't.

I purchased a reuseable filter for my last car, but that's only because due to the ram air system setup, the filter got dirty every few thousand miles.

I used K&N in my Supra for about 50,000 miles. The intake parts of the car (down the valves) got so dirty when I pull the engine apart. I'll will never use K&N again for that reason. I have never seen such a dirty engine before. I have worked many cars/engine.

Just think about it, more air means for dirt. Otherwise how does air get in? Stock filters are the best them all. I don't see an extra 1 to 5HP worths the trades.

You have a point wrxrocks.

K&N dont void warranty. So i guess its okay. I can just blow my engine up before the 6 year 70K miles warranty and get new engine. I know someone who did that but I dont think I will.:coolio:
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2008 G35 journey5at ivory/stone+prem&sportpkg.(k&n airfilters)

It can certainly void your warranty if the oil contributes to the malfunction of your MAF sensors. This was common place on Both Maximas and Altimas. Many denied warranty claims.

How much is the stock filter?

In post #17, I mentioned that a pair of stock filters cost about $20 total.

Nissan dealer wants $20 for one filter.... where can I buy pair for $20? Thanks....

I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.

I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.

I got two from Riverside for $22, $25, something like that.

Man I couldn't wait... Just went to Gardena Nissan told em air filter for 2008 350Z, was able to convince the dude to enter coupon code so they came out to $16 each...

The air filter is made in Phillipines, hmmm i thought it would be Japan... oh well

www.g35parts.com


I believe the recommended replacement interval for the engine filters is 30k. The cabin filter is 15k. But if your filters are already that dirty then...

the k&n drop-in panels are the biggest load of snake oil i've ever seen.

Any of you guys have the stillen intakes? what are your thoughts on the matter...

wait for the injen?

what makes the injen better?

I installed k+n drop ins along with z-tube so I did notice minimal improvement in throttle response and gas mileage. I would like some evidence that k+n filters are not as efficient as oem in cleaning intake charge. Like someone stated before, im sure k&n manufacrtures filters for automakers, I am absolutelty sure they make the air filters for the ah-64d, apache helicopter, because I was aviation in army and actually held one in my hand. With as long as they been around I would expect k+n to have r&d a superior air filter. With as much as they cost Im sure if k&n wasnt a more efficient air filters there would be a hell of alot of complaining and they would have bad rep. in all the motorsports world.

http://www.bobistheoilguy.com/airfilter/airtest3.htm

also, regarding airflow:
"So what do these results mean? For one, there is very little pressure drop across any air filter, and the difference between the best (K&N) and worst (paper) is very small. Yes as total power output increases, air flow increases, and differential pressure would also increase. So a K&N probably does yield some power on higher output race motors where every last ounce of power must be squeezed out. On lower powered street cars, it is probably not much of an improvement over paper. Basically, an air filter is first and foremost a filter, and should be chosen for it's filtration ability. I know after this enlightening experiment, that is exactly how I will select my air filters. Also remember, that this total differential pressure is measured from the atmosphere via the stock Miata air intake tube, airbox, accross the filter, though the test port, about 6 feet of tygon tubing and the manometer and back to the atmosphere. This is not the pressure drop across the filter itself. I may do a quick test with no filter ( I really hate to do it, but might anyway) to get a good estimate of how much is the system itself sans the filter.

For this test differential pressure for the Napa filter is lower due to different atmospheric conditions (different day) and 500 less rpm at the data collection point. That said, it is still noteworthy that the Baldwin and Mazda filter do not flow as well as the Napa, but are still very, very close. In all honestly, all 3 flow about the same or very nearly the same. So it is safe to say from the first test, that the K&N is still the best flowing filter. What is interesting to note is that there was a 5.1 inch of H2O differential pressure in the stock air box and intake piping. If you subtract this different it says worst case one can see a 2 inch of H2O differential pressure loss due to the air filter. This is equivalent to 0.072 psi or very nearly nothing. The air filter posses very little restriction at all in this application. As long as an air filter is properly sized for an application, the lost airflow will be very minimal. This means that there is very little if any power to be found from removing the air filter, much less changing the filter type. The K&N did flow better than the Napa Gold in the first test to the tune of 0.02 psi. That is less than 1/3rd the loss in the factory piping, and it is a whopping 0.14% of atmospheric pressure (14.7 psi). If you need the 0.14% better airflow, than the K&N is hands down the best filter. "

way to go mal...
that was perfect.:7:

ill shut up now

So in other words, K&N filters are better than regular OEM filters? If I understood correct?

they do absolutely nothing appreciable. you net zero gains worth talking about and it's damn near the worst dollar/gain mod you can do. *sigh*

aaaanyway... what makes injen better? nothing at the moment. they're the only folks showing any real gains on their dyno runs, though. the stock setup is pretty well matched for the motor so it's hard to improve just by tossing tubes and cones on

I installed my K&N fitler about 2 months ago, and i'm very pleased with the results.

With the OEM filter I noticed a lag in acceleration, with the K&N there is little or no lag at all! The car feels faster.

I also noticed an increase in mileage.

So its really all about the sound eh... but sadly, I would spend the dough for the sound.. lol I really would. Hearing a nice exhaust sounds just makes me appreciate my car even more... I know.. its bad.., but im sure there are many guys out there too who would do the same. lol

I saw some of the diagrams of the injen intakes.. where do the filters go?

if im interpreting the test results correctly the k+n improves flow by like .14% while sacrificing a slightly cleaner intake charge. in my opinion, and i have k+n installed, I will prolly go back to oems just to keep my engine cleaner inside. if ur looking for a deeper intake note the z-tube is the way to go.

So are you saying I will get the same sound increase wit the z tube without instaling the stillen intakes? And just keeping everything else stock?

I dont know what to do. Im so confused. I keep hearing differing arguments about this issue with dirt/oil build up with non stock setup's.. :S

just my opinion...
but it seems intake is pretty well designed and even aftermarket cai dont net much of a hp/tq gain. the ztube is an oem peice and is desgined for the vq.
so im sticking w/ stock air box, oem air filters (have k+n drop-in now), and z-tube.
to answer ur question, yes you will get sound increase with just z-tube.