Air Filter

[dcnsx]

Hi All.

I opened my airbox yesterday and found the oem filter was a tad dirty. So I've thought about the opportunity of fitting an aftermarket unit, like a pipercross for example. What are you thoughts regards these oiled filters?

Cheers

[goldnsx]

I'm avoiding them. Tests have shown they let too much dirt through.

[The King]

I'm avoiding them. Tests have shown they let too much dirt through.

It is easy to over oil the filter with excess oil getting into the throttle body.

[Kaz-kzukNA1]

Unless you want enjoying the induction sound (noise), no benefit at all at partial TH region.
For C30A engine with just the aftermarket header and exhaust, again no benefit even at WOT despite using the remapped ECU. It’s just that the Eng is not requesting any extra air at all.

For C32B, you may see some benefit only at WOT region but on street driving, how long can you hold at WOT?
Because of this, even with the use of high lift camshaft, many tuned C32B engine owners stay with OEM airbox and OEM air filter in Japan to reduce the induction noise for street driving and also to prevent the potential extra dust into the engine.


From what I saw on many engines with aftermarket air filter, personally, I won’t use it on mine.

It requires careful control on amount of oil to be applied after cleaning and most of the time, the extra oil residue will result in sticky gunk on the TH butterfly and at idle air passage.

You need to be very careful on whether your aftermarket filter is Dry or Wet type as per this blog;
http://www.nsxcb.co.uk/entry.php?1770-Apexi-Air-Filter





https://lh3.googleusercontent.com/20-2fAPYz3o-M2foE-rKVS-WPke5J4ySYFtJ0Y1WV0IMmUkim9uB7THYVzdgXBr0BR5XDf4wC MCLQcwxZ4qmrIaoKT1Y7usNRjl-BCt-UcQX0SiFCDZLLSBFUSut1yJfik6SJxSA07kwhDTnRWiK0FShJq _Xrj1nVXhVbcMF7dkc5apt2stEyFDD5qt0xj5SMBry4fOiL_3a Cv7BtXe73OCaLhFa6OkfTYF3wTwTRdwyHw88YVJUJDgh-rgUBVjoW10InP7mtQiupFdnA5W4wSm4VXisZrIrsdqgJmHV_5Y-ElId1_SrnVdy5AFXzBjNQmkgYnURujN6WTZQEQn_Aj4d3fHzUT bR21y7x7JZXsFe1BRNQBBuEOD9xt-gzHaLFOq5fGQodIB0EX_7K4dsRyI8ZoHnsih2buwvh56L7BM_q Vqs1XS0a-f2V46oDiGqYSRp6eovzraTXddbch6_bnkv5tm3XC8NlbhBupmg 5EL3iDtG7nrJssYKlDKDV26MwdHqQxsu7y35L9is-yc6OZDEtnyxvoiy6ChhgGzj8hL5rfYpCbEkSCIwzBgtlEjhlJw dfXisUmGLRgZQOEsfG6vfsE0HNDi9Sb3X-z9AIGuRcuRP4CG7CQ=w1080-h810-no
If you have a chance to look inside the VVIS chamber, you will see the difference.
With the aftermarket filter, quite often, you will see sticky super fine sand like debris coated with oil.






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https://lh3.googleusercontent.com/FMwwcjLIJR4ql6T1RVg4JOcPTzRWIftfmcNFEIWPf5tec8vDTH lnKkY5AIKq3o9hJBjWcnQe2jJ-31Cbkxo_HjA3PFSAtHdV8Nj98MShfHc8j0KBYWODOicqESWViw zwd4XJ6j2lI1VTWNqsY6DdaNEnWKEZaI952P8jiVjf_KSpiVBs fY3PGp4n0uRhlXjmvZQWXuJc-AYzj0dM5vkLLQVdv7CD06Eh-hfOvFePwfbrbWby-mjO5TQQ_ZeB5J8KQ_jybdUXr1vtNKPkM5VFOaKcYj071jXnZsK eJE8mxjhmdACriDLdLdHigVT0SYf25lxFj_HGJMZ0PSZrd6Vo7 NB7-djp93Ouuvqz8vp5ULTYj5auC7BgzQVEqWWvD-XQcFKBQqVi3JOKIbHcq2RwiqF5DGsAfaMuoe0hz33WNGZY1dH0 H_YIh_oucnLyb6ve7AQqe4ruXtHU_WbuTLAnTm-cvhuhdC-VHhv6lgfNNPQ46klUYMSjNE3slX4zJPTFCvPBp_8xFCN9LLWIZ Z_3R__FtYvtk4XEpmU_ZY9PS9t8z6tlaaugbSReMNXJEbZwrGq 84kYzkDRLITm3VT10q5tbgesS6AOk7TQLWrh2wKINrOQnq2I0g w=w1080-h810-no
With OEM filter, you will only see the trace of TH coating applied to the VVIS butterflies.
This coating is based on the material perfectly safe even if it was swallowed into the engine.


Kaz

[dcnsx]

Thanks for your reply's chaps. Kaz, I think you have made my mind up for me! OEM it is, some things are best left as Honda intended.

[Pride]

Hi All.

I opened my airbox yesterday and found the oem filter was a tad dirty. So I've thought about the opportunity of fitting an aftermarket unit, like a pipercross for example. What are you thoughts regards these oiled filters?

Cheers

Hi Dave.

Interesting.

I have to say that I never asked this question before taking the plunge but had I done so I would probably have come to the same conclusion as you and not of bothered after reading the responses.

To be honest I was really just looking for a more throaty induction note, which I must say, this kit certainly gives in abundance.

Although Kaz has seen dirty throttle bodies with after market kits fitted I can only say that my experience of dirt getting through is comparable to that of the oem induction kit and I've had my car nearly 20 years now.

There are many induction kits availible for the NSX, many do not give any gains over the factory setup. Downforce is one of only a few that give real gains and proved so by Science of Speed.

Downforce intake is one of the most sort after and best intake systems availible, it is similar to the Mugen design, made from Carbon Fibre and very light. It looks great in the engine bay also.

My kit has the optional extra's that were offered. It has the upgraded Carbon Fibre back plate over the Alluminium plate that comes with the kit. Which i also have and use.

The kit includes the much larger Intake scoop, (which I'm sure is what gives it it's distinctive induction note) and replaces the restrictive much smaller factory version. However some holes have been drilled in it as it illuminates the possibility of any water sitting in the scoop after a wash or rain.

Here are the parts:

https://www.scienceofspeed.com/index.php/nsx/eap/intakes-induction/downforce-stack-intake-system-carbon-fiber-nsx-1991-05-df-aaa550.html

https://www.scienceofspeed.com/index.php/downforce-air-intake-scoop-df-aaa500-nsx-1991-05.html

I think provided you service the filter kit accordingly then only positives will be gained.

[goldnsx]

A scoop attracts double the amount of dust than the OEM one. The sound is nice though.

You can do an engine oil test. High silicon (dust) is very bad for the engine.

[Pride]

A scoop attracts double the amount of dust than the OEM one. The sound is nice though.

High silicon (dust) is very bad for the engine.

So you think the SOS kit is bad then how about this:

12769

[goldnsx]

Nice trumpets but...:)

[wixer]

Interestingly, on the subject of induction noise, I've noticed, while I have the wheel arch liners removed, that there is a helmholz resontator as part of the OEM intake ducting. I'm guessing Honda fitted it, to get the noise to a certain DB level, to meet drive by noise regulations.

Will the removal or blocking off of this part of the system make any difference to the induction sound ?

[dcnsx]

Also something to note is as we drive on the left side of the road here in the UK the intake is above the gutter which is generally where most of the dust and crud ends up. Drive on the ride side and your intake is in the middle of the road which is generally cleaner. I wonder if the Honda guru's thought of that as they drive on the left too?

[Sudesh]

No point at all in changing from OEM system....Only benefit is very very very small amount of weight reduction, still not worth it. I ran with the Cone designed in my car for a while, but ended up going back to standard. I could build an OEM Carbon fiber exact OEM unit or In Kevlar, but not worth while unless the numbers of people where interested. It also wouldn't be cheap at all, so again not worth changing from OEM.

I think I still have an intake scoop like the downforce one at $195.00

If I can find it, I'm willing to give it away, all that is asked is to donate some kind of money to the club...

Sudesh..........

[Pride]

Hi All.

I opened my airbox yesterday and found the oem filter was a tad dirty. So I've thought about the opportunity of fitting an aftermarket unit, like a pipercross for example. What are you thoughts regards these oiled filters?

Cheers

If all you're only concerned about the filter being a "tad dirty" and not too interested in a lovely induction note along with an increase in power then just replace the filter, simples.:)

[UnhuZ]

Hi,

i use a flat K&N filter in the OEM airbox since i had the car... in fact, the car came with a K&N filter
already in it, i just bought a spare.

Thanks,
Nuno

[dcnsx]

Im not concerned, a dirty filter shows it's doing it's job. Im not looking for any power gains or induction volume increase just simply is the panel filter worth changing for an oiled one. But to me it sounds like it's more trouble than it's worth. OEM filter on order.


If all you're really concerned about then dcnsx is the filter being a "tad dirty" and not too interested in a lovely induction note along with an increase in power then just replace the filter, simples.:)