is it even worth the cost difference
 

K&N filters or not is it worth it. Do they really make that much of a difference?

A few members here have gotten between 4-6hp gain by going with the k&n drop in filters. Considering they are reusable and gain power I would say they are worth the price.

It's worth if you are only replacing the stock filters, and not comparing it to CAI

Thanks sounds like i'll be going with K&N then.
heard they may improve the exhaust note a tad?

I doubt it, and even if it does, it would be very subtle. I'm still on stock filters with an aftermarket exhaust. I'd say save up and get a CAI.

I think there was a subtle difference in sound, slightly more aggressive, but very slight.

If you are interested, I have K&N filters I need to sell. They had a little over 5k miles on them. I've just been slacking to take pictures and make a thread.

it is a nice upgrade you will feel/hear only if you are sensitive to a vehicle. it does make an intake note difference as well. Worth it? For me, yes. For some, no. Can it be compared to a CAI, nope. Choice lies with you ultimately, no with us.

i'll never use k&n again, let's way too much dirt through. look inside a manifold that has a k&n filter on it after 10k miles. it will be black and coated with mud inside.

Are you saying you ran it 10k miles, before cleaning?

that is more likely from it being over oiled in combination with the oil blow-by from the PCV. You'd be amazed what an PCV oil-catch can can catch, even on a brand new car. Test prove K&N's filtration is superior to other aftermarket filters and almost as good as paper.

K&N's testing? no thanks.

I've used K&N on many of my cars, I know from personal experience how much dirt they let through after taking the manifolds off.

If that 4hp is worth it to you, go right ahead, but I gaurentee after 30k miles, you'll loose that 4hp from reduced compression.

HKS power flow was horrible when it first came out in the early 90's. many cars had to have their engines rebuilt because did not filter at all... Now the power flow filters have sticky oil on them, when they first came out, they had no oil at oil. they were run dry.

I wish I had pictures from when I took my 1jz manifold off my supra. It had a k&n cone filter from when the engine was new. At 80k miles, my air temp sensor inside the manifold had 3/8" of dirt caked onto it. After that I only used OEM paper.

That engine was also was way down on power because the rings were worn.

no, i am saying 10k mile of use.

besides, if you don't clean a k&n, if will filter dirt better, but be more restrictive.

i used to wash them when they looked dirty.

these are extreme conditions, but you'll find many people complaining about k&n and letting to much dirt through.

K&N Filters let in way too much dirt. - Raptor Forums: Yamaha Raptor Forums

K&N Filters let in way too much dirt. - Page 3 - Modded Yamaha Raptor Forums

K&N Air filters Vs Foam - Yamaha Rhino Forum - Rhino Forums.net

I've since switched to UNI foam filters on my modded cars. those are great, but for my 370Z, I'm sticking with OEM Paper.

I'll report back on next Tuesday on if they made any additional horsepower. Today I got a few runs with the OEM filters but I didn't get fully tuned because of a fkin exhaust leak. Alas, my drop ins arrive tomorrow and then its back on the dyno for a fix next tuesday so I guess you can wait.

if you really want to see an improvement, mod the airbox (before the filter) and make the intake hole larger, or add additional holes.