I personally don't feel it is worth it to get a K&N on the G. The oil on the filter will probably end up messing the sensors on the MAF like it has on other Nissan 3.5 like the Maxima. Plus you have to pay for the the recharge kit and the up front cost. Not worth it for a 1 hp increase at best and probably not even proven.

 

Modern intake tracts prior to MAF have become very very efficient in the search for every horsepower to brag about in magazines. The need for quiet power to sell cars has reverted to the " sounds of power" so all that expensive wasteful sound reduction tuning engineering is no longer spent on air intakes.

Measure the pressure differential in front of MAF after oem air filter to see what's possible...........usually less than 2.0" Water column on modern designs 2.0/27.7=0.0722 x 6.66%=0.48% or < 0.5% available if the restriction were not there.

1.3-1.4 HP but you can't get by with no air filter or housing so say 0.7 HP at best.

Many times changes to air filter, housing or piping results in changing [fooling] MAF calibration curve which can [lean] fuel making more HP in certain situations at the expense of other problems.

 

To answer the original post, no there really isn't any proven or noticable gains from it. The only advantage is the re-usability of it, but if you over-oil it you can mess up the MAF.

 

Does the K&N drop in filter make the engine a little louder...a little more humming? I have one of those cone shape filters for my accord (don't laugh...i am not a rice boy). It's been in there for a long time but it makes a pretty good engine noise when you gas it.

 

Since the K&N is cheap (Grubbs selling it for $35) and can go so long between cleaning/re-oilings, I'll just buy a new one when it comes time for a change and won't bother screwing around with cleaning and re-oiling it. New ones come in the box pre-oiled with the correct amount of oil. If you clean and re-oil it yourself, you run the risk of over-oiling it.

I have a K&N Filtercharger on my '91 Nissan 300ZX which has 164,000 miles on it. No MAF problems ever with the Z and the MAF is very close to the Filtercharger. Had a Blackstone oil analysis done recently and they happened to comment that the air and oil filters were doing an excellent job- I didn't tell them what kind of filters I was using.

In the Z's case, I do clean the Filtercharger and re-oil it every 50,000 miles since new ones are more expensive than the Drop-In for the G.

In the G's case with the K&N Drop-In, I don't know about the performance gains for the G, but I believe the K&N filters out more particulates from getting into the engine than the cheap stock filter does. I love my ZTube/K&N Drop-In combo. I hope whatever you decide to use works out well.

 

Take a look at this test. Interesting results.

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

 

very interesting link. i've had 2 cars prior w/ K&N cone filters (WAI) and didn't have issues with them. not sure if i'm gonna do it on my g35... i think it's loud enough as it is. really drones when i'm going 50-70 in 5th.

 

You can try the AMSOIL air filter. It is a oiled foam type dual-density. It was $30 and is cleanable as well. The fit in the stock houseing was much better and you don't have any hissing like with the K&Ns. Its another avenue you could try.

 

I will stick with the stock filter and go with the Z tube. Have your hooked up a SAFC-II to a normally aspirated G?

 

Pimpinpearl has and his car was running pretty well last time I was with him. He has an exhaust and an intake, not sure why he thought he needed to change his a/f. I'm also considering getting one since I'll have the intake, plenum, headers (on order), cats and y-pipe. I figure I'll go to a local place that knows a thing or two about tuning and have them dial in the correct a/f for my vechile and just leave the unit alone after that. It is a little cheaper than the TS ECU reflash and it allows you to tune the vehicle, not the ecu.

BTW, (just to stay on topic) I've had a new K&N pannel filter in my laundry room for ~3/4 months now. Just waiting for the stock paper filter to get dirty enough to swap it out I guess. (Either that or I'm just too lazy to put it in).

 

I have some issues with that test, since it's done over a period of distance vs a period of airflow. If I put a crappy filter on my car and did the same test, and the filter was highly restrictive, I'd also see less particles on the 2nd filter. Not because the crappy filter was better from a filtration perspective, but because it was worse from an airflow perspective, ie, less air flowed over the 2nd filter in the same number of miles, with a richer running engine. It's not the most scientific of experiments to say the least. What would be a better test is comparing filtration with a fixed volume of air and not over a period of miles where smog levels and dust levels from day to day would/could vary greatly.

 

Agreed. The variables and environment in that test wasn't exactly controlled 100% like a full scientific experiment would call for. But that doesn't automatically dismiss any or all findings and results of that test. It just means take it with a grain of salt and use it to help you make up your mind.

 

I have done some searching around on other forums. Basically taking a more extreme approach. Looking at dynos with stock air boxes and stock filters vs dynos of the stock filter removed (no filter) at best there was maybe a 1-2hp/tq gain in the extreme high end. Now obviously the KN is more restrictive than no filter. Basically extreme minimal gains. Not worth it in my opinion with all the cleaning and oiling etc... and the possibility of oil on the maf sensor. Stock box, stock filter, ztube and your good to go.

 

It pays for its self pretty quick as it will last forever. We live where it is dusty so a stock element gets swapped a few times a year at worst. I have never had a problem with the sensors either... Is the panel filter going to make wild power improvements, no, not for us...

 

I had a K&N in my F150 Lariat, then tried it in my Mustang GT (same filter) and I didn't notice anything different at all, as far as sound goes, I wouldn't have been able to hear it over the GT's exhaust anyway! I guess the permanent feature may be okay, I don't know what the kit costs to clean and reoil it costs though.