Need help with decision on K&N filter or Uni filter w/stock airbox and DF air scoop?

[MileHighNSX]

Need help with decision on K&N filter or Uni filter w/stock airbox and DF air scoop?

Hey guys I need some help after reading this thread: http://www.nsxprime.com/forum/showthread.php/54964-Down-Force-intake-Scoop-Wow! It looks like I'm going to get the DF air scoop plus a K&N drop in for the stock airbox - or - a unifilter? I don't know exactly what a unifilter is, so I thought I would ask you guys if it's a drop in replacement (oiled) just like the K&N? Just need some advice on which drop in to get for the airbox. Also I know that the thread is pretty old, is the concensus still positive that the DF air scoop is the one to get? I saw it on SoS website. Thx....

 

[Hapa88]

Uni Filter is just another brand of aftermarket air filters.
http://www.unifilter.com/

They are oiled foam filters vs the oiled cotton gauze filters of K&N. It is a drop in style filter like the K&N, so there shouldn't be any modification like with the K&N version. Which is better? I'm sure there's quite a bit of debate depending on who you ask.

 

[MileHighNSX]

Thanks for responding! I was starting to wonder if I would get a response on this topic?

You said that you need to modify the drop in K&N filter? How so? Still haven't made up my mind yet on which one to get.

Thx

 

[Rope]

I have the DF scoop and the Uni filter and I like how much it filters out versus the OEM filter. It does need to be cleaned every oil change as the filter gets really dirty with that scoop. I don't know which on is better between K&N or Uni, I don't think it matters which way you go but then again I have an Uni and can only speak on it.

 

[nsxtasy]

I had a K&N air filter on my NSX. There was no noticeable performance gain (although it increased the engine sound). Plus I heard some horror stories about aftermarket air filters being the only so-called "light mod" that has actually been associated with engine damage in some cases. I went back to stock.

 

[latzke]

$200 for a piece of plastic that helps you suck in more dirt and water.

Is lack of marketing the only thing keeping leaky tire valve stems from being the next cool mod?

 

[Rope]

I believe the K&N filter damaging the engine is due to over oiling it and on engines with MAF sensors. It coats the MAF with oil causing it to start to malfunction. I have a 1991 so I do not know if it is on the OBD II cars or not.

 

[docjohn]

I used the uni filter for many years..and I got a gunked up TB and vacuum passages for it.If you are going to use it you need to oil it sparingly.

 

[Gansan]

That's good to know. The instructions from Uni say "you can't over oil it" or something like that, so they want you to really put a lot of oil.

 

[docjohn]

I'm back to the oem filter with the free flowing comptech box

 

[MileHighNSX]

I used the uni filter for many years..and I got a gunked up TB and vacuum passages for it.If you are going to use it you need to oil it sparingly.

Wow! was it worth it running it for the time you had it in? If you oiled it sparingly like you stated would that have made a difference in your TB & Vacuum passages? I don't want to put anything in that's going to affect my engine negatively.

 

[docjohn]

part of the problem was that I was letting my tech do the cleaning/oiling.....I was having idle rpm drop/stall issues.....As stated by others the perceived benefits are from the greater sucking sound, none of us will feel 1-3 hp.Now we should never forget the amazing turbinator...:wink:

 

[MileHighNSX]

part of the problem was that I was letting my tech do the cleaning/oiling.....I was having idle rpm drop/stall issues.....As stated by others the perceived benefits are from the greater sucking sound, none of us will feel 1-3 hp.Now we should never forget the amazing turbinator...:wink:

LOL:biggrin: how could I forget the turbinator. When I was younger I did buy one and tried it on one of my cars and needless to say I don't know how they stood on the market for as long as they did (Returned it the next day after my car sounded like it was winded for air)! Anyway I would be running it with the DF airscoop +Uni or K&N. The link that I posted in my original thread was pretty lengthy and old, but it did have some good information when running both of them together and some actual gains with both of them coupled together. I know some people think that it's not worth the $$ but I guess that's why we have forums and opinions to discuss them in this setting. Anybody else want to chime in with their experience with the DF airscoop currently being sold by SOS & the Uni filter or K&N together?

 

[Honcho]

I second Docjohn. I had a K&N on my NSX when I bought it and the throttle body was all gunked up with oil. I switched to the stock airbox with OEM paper filter and could not be happier.

 

[MileHighNSX]

Good responses! Let me ask this question: So far Docjohn & Honcho have had issues with the TB getting clogged up with oil, one with the Uni & the other with K&N, so it doesn't sound like it's prevalent with one over another. Is there something about the NSX air induction system that would accelerate that kind of problem with aftermarket filters that are oiled? I'm asking because every car I've owned since I've had my license at 16 has had a K&N filter in it. I have had no issues with fouling of the MAF sensors or vacuum lines. So it brings me back to my original question, is it something with the air induction system on our cars that make them sensitive to these types of filters? Or could it be just an issue of over oiling either type of filter?

 

[Rope]

well considering most cars don't have the filter 3 inches away from the throttle body might have something to do with it.

 

[MileHighNSX]

well considering most cars don't have the filter 3 inches away from the throttle body might have something to do with it.

Really it's that close huh? I've only had my car for about 2 weeks so I guess I haven't looked that closely at the intake system to realize that the throttle body is that close to the exit of the filter!

 

[Coconut]

^Yup, you got the throttle body, that short 3" of flexible tubing then BAM, the air filter is right there. I believe the B-Line CAI relocates the air filter (cone) all the way in the fender.

 

[MileHighNSX]

I guess that would make sense then why some guys have had issues with oiled aftermarket filters. You have increased air flow from the aftermarket filter, then couple that with the DF air scoop and the resulting increase in airflow can cause excess oil to make it's way 3" over into the TB. Sounds plausible

 

[silver2002]

Here are some photos. I went back to stock. I understand that stock may well be more efficient than K&N - I wasn't sleeping well with the K&N although it did sound better. Here are some photos - one with light coming through.

 

[MileHighNSX]

Here are some photos. I went back to stock. I understand that stock may well be more efficient than K&N - I wasn't sleeping well with the K&N although it did sound better. Here are some photos - one with light coming through.
View attachment 104787View attachment 104788View attachment 104789

That was eye opening for sure. I didn't realize that the K&N was so small in area covered on the filter? It doesn't look like it filters as well as the OEM filter. Anybody have a side by side comparison like this one, only with the Uni filter right next to the OEM filter?

 

[nis350]

I used the uni filter for many years..and I got a gunked up TB and vacuum passages for it.If you are going to use it you need to oil it sparingly.

I usually put very little oil on the inner side of the uni-filter (TB side) and a bit more on the outer side. The uni-filter is a dual stage filter where the inner portion is denser. So if you put more oil on the outer portion and it is probably less likely to pass through the denser portion of the filter. Hopefully the oil stays in the middle of the filter.

I think the uni-filter (~ one inch thick) is thicker than the K&N filter. The oil it uses is also quite thick and probably less likely to get sucked into the TB if oil properly.

 

[latzke]

Back in the day CT recommended the Uni filter and I believe the CTSC kits included the Uni filter. Is this still the case? What about SOS's SC kit? Are many CTSC/SOS-SC folks running the OEM paper filter?

- - - Updated - - -

View attachment 104787

At least the Uni uses the full area. Clearly the question seems to be between OEM paper and Uni.

 

[WillErickson]

Still on oem paper filter and oem air box with my CTSC, autorotor bought in 2006, no filter included.

 

[lithiumus]

Bringing this thread back from the dead... [MENTION=4282]docjohn[/MENTION], I see that you are using the comptech intake, I found that the OEM filter actually doesn't fit properly in the CT airbox. How did you get it to fit? I had to trim mine...
I've been running my Unifilter with almost no oil... just a light mist.