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Thinking about going back to stock air filter..

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I'm thinking about going back to stock air filter on a CTSC. Been running the UNI filter and recent oil analysis got some funny results which could be attributed to clogged/not perfectly cleaned/oiled air filter.

Cleaning the air filter is always a pain for me. Gotta rip out the airbox, go through a few iterations of cleaning it untill all water flows through it is clear taing over 30 minutes.... and you always take the risk of not quite doing it right + one of the areas in the corner is always a darker purple that I can't seem to get out.

Then you have to oil it, but not oil it too much.. let it dry for 24 hours or else you end up getting a bunch of oil in the airbox. It's hard to tell whether you have oiled every inch appropriately.

With stock air filter it seems much simpler. Check it every/other oil change, if it looks dirtier than you're comfortable, change it.

I'm thinking, except for costs, there isn't any downside, right?

I know It will get less air in, and thus richen the fuel and may rob some power. Richer is better than leaner so that's fine. As long as it's not more than 5 HP or so.. not too concerned. Could it be more than 5 HP?
 
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Just do it, I will do the same once my car is up and running.
I just did some test on the three filters on friday for airflow and find no great pressure drop associated with the stock filter.
I will feel safer with it.
Its just too much hastle to get your engine rebuilt.
Trev
 
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i had the same question also....I was going to use the K and N since it seems to clean better and easier... Pretty Much the same price. I was going to actually retro the K and N cone into the oem air box...
 
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I vote for the stock filter too. I just changed mine because the unifilter was making my idle funny. It would go down then up. I changed to stock and the problem went away.
 
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I am a big advocate of the stock airbox, but two CTSC owners I have discussed intake systems with have mentioned the car feeled restricted by the OEM airbox, compared to aftermarket solutions which otherwise might provide only a marginable benefit. This could be placebo effect from a louder intake system, but perhaps try the stock element, and the unifilter, back to back and see how significant the difference is.

Another option could be this:
http://www.nsxprime.com/forums/showthread.php?p=985779

The AEM dryflow element is good quality, and doesn't require oil. The layout of this system also isolates the element from the engine bay entirely, so your air source will be cold. There is direct airflow through the vent onto the element, which could lead to premature replacement, but this seems like a very interesting solution for nsx's with the oem air filter placement layout.

I would certainly be interested in this option for my '94 nsx, but I use a different intake configuration.
 
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Thanks scorp. I would love to get my hands on a CTSC Nsx with my intake setup. I think it would be a perfect combination.

On another note. A good friend of mine was bored with his typhoon intake on his Srt-4 and replaced the K&N filter for the AEM dryflow and not only did it run better it dyno'd plus 4whp. Not bad for just changing a filter. The aem also doesn't have to be oiled so that should take care of your problems.
 
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I'm too lazy to read the entire thread - will the AEM element work with the stock/CT air box?

I have the CT airbox, which I'm keeping. I am just wanting to change the filter...
 
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Awhile back my uni filter started to deteriorate so I went back to the stock filter,,caveat being be prepared to do some modifying of the stocker's plastic frame to fit the comptech box.:frown:
 
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Awhile back my uni filter started to deteriorate so I went back to the stock filter,,caveat being be prepared to do some modifying of the stocker's plastic frame to fit the comptech box.:frown:

I was just thinking about that possibility... What needs to be done? Shaved or..?
 
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I was just thinking about that possibility... What needs to be done? Shaved or..?

Just need to shave off some plastic from the sides you'll see once you test fit it.Just allow more time.
 
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I use a K&N in the stock box. Easy to clean and oil.

Same here. Been using the K&N for the last 130,000 miles or so (about 4 years). It's cleaned and oiled every 20,000 miles. Recent oil analysis was comparable to a motor with 1/5th the mileage. I use Amsoil 10W30 and Auto-Rx by the way with oil/filter changes every 3,000 miles which means monthly for me.:)
 
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Just an update for this thread. After about 5500 miles with the CTSC, and about 12 months of street and some 6-7 track events, I checked the Unifilter in the OEM box but using the Cantrell air scoop.

According to Shad, the amount of dirt/rubber picked was marginally at the point of needing any cleaning. One corner was still clean/red due to the angle I guess. I had an opportunity to see another Unifilter at his shop that was twice as bad! .......... My recommendation is check it at every 12 mos or 5000 whichever comes first. Since the filter was out, cleaning was a breeze - spray, wait 3-5 minutes, hose down, let it dry and then spray the oil ........
 
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dunno if I want to...just thinking about options. Nothing against the Uni, just trolling for Apexi data...:wink:
 
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I have an interesting thing that has happened twice now.
Pretty good rain coming down.
Using DF side scoop going to stock airbox with UNI filter.
driving normal speeds I feel the engine REALLY bogging down. almost like it is being starved for fuel or something. Press on the accelerator and it barely wants to move any faster.
It actually triggered a CEL the other day when it did it. Oddly enough, after it tripped the light, it seemed to run better.
Do you think there is a chance I was getting enough moisture/water into the system that it was mixing with fuel and causing it to run funny? I personally wouldn't think so but am really curious now.:confused:
 
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I have an interesting thing that has happened twice now.
Pretty good rain coming down.
Using DF side scoop going to stock airbox with UNI filter.
driving normal speeds I feel the engine REALLY bogging down. almost like it is being starved for fuel or something. Press on the accelerator and it barely wants to move any faster.
It actually triggered a CEL the other day when it did it. Oddly enough, after it tripped the light, it seemed to run better.
Do you think there is a chance I was getting enough moisture/water into the system that it was mixing with fuel and causing it to run funny? I personally wouldn't think so but am really curious now.:confused:


Let's go through this inquiry methodologically.

Did you check the Unifilter if it was clean or dirty when this happened the first time? If so, were the incidents back to back or the second time was AFTER checking the first time that the filter was clean or you cleaned it and it happened again?

I have been in 4 hours of non-stop pouring rain on my way back from Laguna Seca to Sacramento 220 miles but with the OEM filter at the time (and with the Cantrell scoop), and didn't have a single hiccup.

I had a very momentary two hiccup incidents - akin to like fuel being cutoff at Infineon two weeks ago both times climbing up to turn 2 or tracking out of turn 10 (which was more scary given that you don't lift under WOT at that turn). No engine light, car continued to rev after the hiccup. The first time I thought it might have been due to not turning the TCS off; but the second time I knew the TCS was off. This is the first time that it had done this - with or without the CTSC/Unifilter. Still trying to identify the what how why - we think it might be intake temp sensing too much heat; the oil temp was reading 260F and the water temp was 205F.

This Thursday at the same track we will see if it does it again with a cleaned Unifilter.
 
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Let's go through this inquiry methodologically.

Did you check the Unifilter if it was clean or dirty when this happened the first time? If so, were the incidents back to back or the second time was AFTER checking the first time that the filter was clean or you cleaned it and it happened again?

the first it happened was several months ago.
I did get home and take the filter out and clean it. it didn't appear to be wet in the filter housing. It did look a little dirty so I went ahead and did some maintenance.
You gotta keep in mind that I don't drive the car very often so I probably haven't put 500 miles on it since it happened the first time.
So having said that, the 2nd time was just last weekend. Now I haven't taken the filter out yet to check it for dirt but truthfuly can't imagine it needing cleaning since it sits so much.
I haven't checked to see what the CEL was either.
When I started it this morning it ran just fine and no light.
 
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the first it happened was several months ago.
I did get home and take the filter out and clean it. it didn't appear to be wet in the filter housing. It did look a little dirty so I went ahead and did some maintenance.
You gotta keep in mind that I don't drive the car very often so I probably haven't put 500 miles on it since it happened the first time.
So having said that, the 2nd time was just last weekend. Now I haven't taken the filter out yet to check it for dirt but truthfuly can't imagine it needing cleaning since it sits so much.
I haven't checked to see what the CEL was either.
When I started it this morning it ran just fine and no light.

If you have the CT box - did you see water at the bottom of the box? If you have the stock box - whic is a more reliable design -there is a hole that will leak the water out so it might be more difficult to tell. To test it, you may want to coer that hole temporarily to see what happens.

PS: If you are using the stock + uni, you should notice that the box doesn't fully close, one of the edges of the filter is too thick (come on Uni..) In addition to the CT box not providing any type of real seal - this only aggrevates the situation. It's very possible that stock airbox + uni in heavy rain could let water "through the cracks"

Also - I can see a scenario where water is so heavy and prevelant, that it gets underneath the car in th engine bay and affect one of the sensors. Very small chance, but if you're going through puddles and stepping on it..
 
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<snip>
PS: If you are using the stock + uni, you should notice that the box doesn't fully close, one of the edges of the filter is too thick (come on Uni..) In addition to the CT box not providing any type of real seal - this only aggrevates the situation. It's very possible that stock airbox + uni in heavy rain could let water "through the cracks"

....


I am not sure I see the fitment issue you raise with my 98-T OEM box and the Unifilter. Sure putting the cover on without first detaching the hose that goes to the intake is a bit difficult - takes a few trials, but I had no problem with one edge not being flush. I checked it with my fingers, and all the screw went all the way.
 
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