Are they worth the extra money? I've heard very opposing views about them.

 

I have had them for over 10 years, not one problem. Never purchased another filter, I just re-oil them.

 

I have one for sale, switched to a pop charger. They last literally almost forever. If you want it the price for mine is 30 shipped.

 

Something to consider, and something I didn't know about until about a week ago, so take it for what it is, as it concerns another car. I was talking to a guy about the 05 GTO, and he was telling me that if you put a K&N filter on an automatic, you will blow your transmission due to excessively high line pressure. Seems GM calibrates the line pressure off the air sensor, and when the oil from te filter would get on it, it would heat up more, causing the computer to force the line pressure higher. I don't think it affects our cars with autos, but it might be worth looking into. It would be a shame to have a blown tranny and have to replace it out of your own pocket.

 

at a recent dyno day in the UK a few types of filter were tried on the same car. The K&N was the only one to lose hp

 

both posts above have no evidence. Wonder why? I have always run K&N filters and nothing else (besides this popcharger) and they have been nothing but a benefit. All of this losing hp bs is exactly that, BS. Replacing an air filter from a PAPER HIGHLY RESTRICTIVE filter to a less restrictive filter would in fact gain horsepower in theory. If the K&N drop in filter loses hp like you claim, then every single intake other than the select few that replace the stock airbox with a new one, would lose hp, as well.

 

Seeing as how you stated both above posts, and mine was one of the two previous, I'll assume you are referring to mine as well.
In defense of 3fidd, if you over oil the filter, yes, you will lose power due to more restriction in the airflow. Even with your insight into this situation, you should have been able to pick that one out. As for my post, there is a GM bulletin out on this very subject. Take an 05 GTO in for service, and they will void the warranty on automatic transmissions. I was simply stating that it might be a good idea to look into this a bit more before doing it, as there is a slight possibility that it could affect our cars.
I personally have a K&N filter on both my Jeep and my Chrysler Sebring, and it has done nothing but good for them. While I haven't placed either on a dyno, they have gotten a few more MPG than before.

 

The 350Z stock airbox is VERY good compared to some other stock intake systems out there. Add that to a very "unfriendly" ECU and gains from bolt-ons are minimal without a reflash.

 

I never said that an intake OR boltons on the 350z make a huge difference, I simply said that they would make horsepower. About the stock airbox vs other intake systems, I completely agree with you. The K&N drop -in in the stock air box performs nicely. The only reason I switched to the pop charger 2 years ago was due to the sound difference, the popcharger really opens up the exhaust tone.

 

Conceyted,

Just to confirm 3fidd's post from earlier. We tried the K&N panel, stock panel and Nismo S tune panel in the same car back to back on the dyno. Very little difference between the stock and the S tune filters (about 1bhp) however the K&N lost 3bhp.

K&N filter was brand new, out of the box, so if it was over oiled - that will be K&N's responsibility as its shipped pre-oiled by them (it was fine by the way).

The Zed used was a UK spec '04 350Z GT. For evidence please ask any of the 20 Zed owners who attended the northern UK dyno session over at 350Zuk.com.

Nothing against K&N - used them on plenty of my previous cars and had no problems at all - just when we tested the filters in the UK a few weeks ago - it didnt do so well in that specific test.

Cheers

RickB

 

Dynos are not accurate to such small hp readings as they have a certain error percentage. So I am assuming you guys did 3 runs each and averaged them per filter? If you did one run each thats about as accurate as me saying it feels like I gained 10 hp from a muffler addition.

 

I bought mine on an impulse when I was getting oil and an oil filter. It felt a little different when I put it in... good? bad? faster? slower?... don't know but it did feel different.

 

as long as you don't over oil - no harm, no foul - just about everything else is subjective