Cone Filter, yay or nay?

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2003 Protege5
I know a popular mod is an open element cone filter, so for those of you using one or who have in the past, specifically on a stock MP5, let’s hear about it.

The reason I ask, I’ve had open cone filters and cold air intakes on my high revving Hondas, I’ve ran them on quads and mopeds and my Ruckus, even a Suzuki Samurai, but about 13 years ago I put an Injen air intake with cone filter on my stock Nissan S13 and I LOST low end power.

Many “newer” vehicles are tuned from the factory and things like an air box delete actually can make you lose power.

I love the look and simplicity and the sound of an aftermarket air intake, but I won’t do it and sacrifice power.
 
Man, you had a Sammy? Damn lucky man! I used to own a 4WD 91' Suzuki Sidekick, and that was a hoot in the trails! You should see the Japanese equivalent to those. They're called Jimnies, and some of them come with turbocharged 660cc engines. You can import them for real cheap, too.

And I see you say that you lost low-end power with that intake. Was it a CAI, or an SRAI?

Anyhow, onto cone filters...This is just my opinion, but I'm very skeptical of aftermarket air filters. The whole idea of an air filter is to block harmful airborne particulates from entering your engine via your intake, yet a lot of these cone filters advertise "higher-flow". A higher flow means less filter, which means a higher chance of engine wear to occur. For that reason, given how I'm not going to be racing my car a lot, I'm sticking with the box filter. Plus, I've read from somewhere that the P5/MP's box filter is actually really good for what it is, and may not be worth taking out.

But what I want to do is investigate fitting the stock box filter onto a SRAI. I can't say I've seen it done, and I would have peace of mind knowing that I'm not letting god-knows-what into my engine (while making the engine sound better and getting a slight amount of low-end power).
 
They're called Jimnies, and some of them come with turbocharged 660cc engines. You can import them for real cheap, too.

And I see you say that you lost low-end power with that intake. Was it a CAI, or SRAI?

Yeah, I know all about the Jimnies, I was in the Suzuki game since the mid 90s.

The Injen intake I put on my stock KA26DE was short ram, you could feel the loss from stop light to stop light, but it opened it up on the highway, I preferred torque though.

As for the filtering, I still trust their filtering, plus I always treated my cone filters with the K&N cleaning and oiling kit.
 
The Injen intake I put on my stock KA26DE was short ram, you could feel the loss from stop light to stop light, but it opened it up on the highway, I preferred torque though.

As for the filtering, I still trust their filtering, plus I always treated my cone filters with the K&N cleaning and oiling kit.

Good observation. Your stock airbox is designed to be quiet, but it offers better torque and flow at lower RPM's and balances out the whole power band better.

However, in your case the reason why you noticed a loss of torque from stop to stop is your "cold" air intake breathing in warm engine bay air and degrading performance. This is why you feel the slightly extra power on the highway at speed when the cone is being supplied fresh air.

I had an old Honda accord 5 speed back in the day with a cold air intake on it, and I remember that the intake was never all that amusing when it came to an actual performance increase, it was just more engine sound than anything else but I remember taking a bolt cutter and cutting out one of the old fog lights to feed fresh air directly to the intake and overall it made a very noticeable difference. Revving past VTEC, you could hear the engine suddenly breathing harder, the shifting became smoother and it overall made the car better to drive.
 
However, in your case the reason why you noticed a loss of torque from stop to stop is your "cold" air intake breathing in warm engine bay air and degrading performance. This is why you feel the slightly extra power on the highway at speed when the cone is being supplied fresh air...it was just more engine sound than anything else...

You seem to have a good grasp on intakes, so I got a question for you:

Say I bought an AEM SRAI, but modified it to fit the old airbox and filter rather than the cone filter. How would the powerband react to that? Would that even be a good idea to begin with?

My car is missing the front dam air scoop piece that runs across the radiator, and I suspect that it may be part of the reason why I'm getting a lean bank code. I can't find said piece anywhere, so I'm investigating my options.
 
You seem to have a good grasp on intakes, so I got a question for you:

Say I bought an AEM SRAI, but modified it to fit the old airbox and filter rather than the cone filter. How would the powerband react to that? Would that even be a good idea to begin with?

My car is missing the front dam air scoop piece that runs across the radiator, and I suspect that it may be part of the reason why I'm getting a lean bank code. I can't find said piece anywhere, so I'm investigating my options.

By the air scoop thing, do you mean that big piece of plastic right about your radiator? That part is important. It helps feed cool air from underneath the hood to avoid heat soak, so I would try to fabricate something myself to put in place of there and see if that helps with the lean condition. Your car could also be potentially running lean due to something else such as a vacuum leak, faulty O2 sensors, etc because I don't see how missing that piece would cause you to run lean.

As for modifying your current airbox with your cold air intake - well I don't exactly recommend against it, but I personally don't see much of a point in mixing the two parts together looking at your airbox design it seems relatively well designed and the restriction seems to be in the box itself, so unless you modify that to flow better you will not notice a difference in performance by changing only the metal piping and leaving the plastic airbox intact like you implied.

You can try modifying your current airbox (should be info about this online) but whatever you do, stock airbox or aftermarket short ram you're gonna be best off if you can figure out how to feed fresh air from underneath the hood into the intake, especially if you're gonna be installing that short ram. Short rams are notorious for just sucking in hot engine bay air, so unless you can feed it fresh air somehow I don't advise installing it.
 
Hey man, thanks for the detailed response. Perhaps the the big piece of plastic by my radiator isn't the biggest cause of the code I was thrown, but I suspected that it certainly isn't helping by not directing cooler air into the intake. I'll definitely direct my money towards replacing that part or building a replacement, since that seems much more pertinent.

Your response lead me to do some research on creating a bespoke cool ram-air system, and I found this content-rich thread at club protege regarding "negative boost elimination". It discusses the effects of using the stock intake system to both improve mpg and performance, and seems legitimate:

http://www.clubprotege.com/forum/showthread.php?1977-Modifying-the-Stock-Air-Intake-System

As a quick summary, drilling out a few parts in the grille (high-pressure area) for airflow, plugging a few drain-holes in the plastic radiator piece (but leaving one or two open due to the upward slope of the path of air and how water is heavier than air), and removing the MAF mesh results in a quicker throttle response. All of this was free ninety-nine, and seemed to be universally approved by the forum.

Any thoughts on it?
 
That flat area behind the grille is a mighty fine place for storing tools and bolts. I sure wouldn't want to cut it out.

I'm always skeptical about these types of mods because they are ripe with expectation bias. I like to believe that if gains were that easy to be had, Mazda's engineers would have taken advantage of them. There could be some truth to them though, you won't know if you don't try.
 
Both my grilles are already bashed up and need replacing, so I believe some cutting for Protege science wouldn't do me much harm :^)

The original poster of the thread, goldstar, has a very good root in general physics in all of his postulations and reports. Thing is, I don't think I've seen hard, written-down or officiated empirical data on the benefits on performance. Yet, the forum thread was filled with people encountering similar effects of performing the above modifications. Heck, goldstar himself mentioned how he ran that modification for a year or so without any issues.

Maybe I can make a much more official testing and procedure, and run some dyno tests? I'm all for enacting ye olde scientific method every once in a while, especially if it's on cars or electronics!
 
Hey man, thanks for the detailed response. Perhaps the the big piece of plastic by my radiator isn't the biggest cause of the code I was thrown, but I suspected that it certainly isn't helping by not directing cooler air into the intake. I'll definitely direct my money towards replacing that part or building a replacement, since that seems much more pertinent.

Your response lead me to do some research on creating a bespoke cool ram-air system, and I found this content-rich thread at club protege regarding "negative boost elimination". It discusses the effects of using the stock intake system to both improve mpg and performance, and seems legitimate:

http://www.clubprotege.com/forum/showthread.php?1977-Modifying-the-Stock-Air-Intake-System

As a quick summary, drilling out a few parts in the grille (high-pressure area) for airflow, plugging a few drain-holes in the plastic radiator piece (but leaving one or two open due to the upward slope of the path of air and how water is heavier than air), and removing the MAF mesh results in a quicker throttle response. All of this was free ninety-nine, and seemed to be universally approved by the forum.

Any thoughts on it?

Sounds good to me. The stock air intake is not badly designed at all. I have no doubt whatsoever that you can get better MPG and performance by simply modifying how the air flows and you got a whole forum thread asserting that, so I'm confident it's a better choice over a short ram.

At the moment, the best thing you can do is makeshift something for that piece above the radiator, then modify that airbox.

You can also get a steady supply of fresh air (without it getting interrupted due to the radiator flow) with some carefully-placed hood vents. The back of the hood, closer to the windshield is a high pressure area for the intake of air for your engine, while the front half portion of the hood is a low pressure area for exhausting air out of your engine bay which will improve overall car airflow but also completely prevent any sort of heat soak, meaning you can actually gain some benefits of a short ram intake while also helping your engine run cooler, thus increasing performance. Once you get the airflow of your engine bay optimal, then you can start increasing air flow as the stock airbox becomes a restriction.

The stock airbox is most certainly a restriction if you are chasing after big power figures, but like the thread mentioned the best performance and mpg will he achieved with the modded stock airbox. The design is already quite good for retaining low end torque and stuff like that, just needs more airflow as mentioned in the thread.
 
...You can also get a steady supply of fresh air (without it getting interrupted due to the radiator flow) with some carefully-placed hood vents. The back of the hood, closer to the windshield is a high pressure area for the intake of air for your engine, while the front half portion of the hood is a low pressure area for exhausting air out of your engine bay which will improve overall car airflow but also completely prevent any sort of heat soak, meaning you can actually gain some benefits of a short ram intake while also helping your engine run cooler, thus increasing performance. Once you get the airflow of your engine bay optimal, then you can start increasing air flow as the stock airbox becomes a restriction.
Man, if I was a Mechanical Engineering major, I would so do something like that for a fluid dynamics/mechanics project. This makes me want to do some reading, but I'm going to have to figure out where I should start!

You definitely know your stuff man, mad respect from someone who's still trying to learn the ins and outs!
 
...regarding "negative boost elimination". It discusses the effects of using the stock intake system to both improve mpg and performance, and seems legitimate:

http://www.clubprotege.com/forum/showthread.php?1977-Modifying-the-Stock-Air-Intake-System

As a quick summary, drilling out a few parts in the grille (high-pressure area) for airflow,...

One of the only "mods" I've done !!

Free and easy...
My only real concern was not just ramming air but water as well when it rained, so I didn't plug any drain holes.

I forget if I removed the MAF screen ??

I remember at the time reading about how Mazda was working with an aftermarket intake designer (I forget who) to try to create a better intake system.

They could only come up with very marginal gains over the stock system so the collaboration was stopped.



I did lose half a tool tray for the mod but most of my tools fit in the right side.
 
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I could've swore it was Racing Beat that Mazda was working with. They came up with some form of an SRAI that almost did the trick, but just didn't cut it. It suffered from heat soak like any other SRAI, so they canned it.

That's good knowing that someone on this forum also tried out this modification. Would you say you felt and/or hear much of a difference?
 
Would you say you felt and/or hear much of a difference?

I don't remember noticing any difference... I was keeping track of my mileage but it didn't change much.

Didn't seem to hurt in any way though, and it's free...
 
Don't forget that the Ecu would need some time to adjust to the modification in airflow until you reach optimal performance. This process happens quicker when you turn the car on and off (cycle the ignition)

My next suggestion is some exhaust work.
 
Anyhow, onto cone filters...This is just my opinion, but I'm very skeptical of aftermarket air filters. The whole idea of an air filter is to block harmful airborne particulates from entering your engine via your intake, yet a lot of these cone filters advertise "higher-flow". A higher flow means less filter, which means a higher chance of engine wear to occur. For that reason, given how I'm not going to be racing my car a lot, I'm sticking with the box filter. Plus, I've read from somewhere that the P5/MP's box filter is actually really good for what it is, and may not be worth taking out.

You have to keep in mind surface area as well. A K&N Cone filter, UNI filter, etc. properly oiled will keep out just as much, if not more than the stock paper element air filter. That's the purpose of the oil, to make it sticky. Without the oil, you may as well have no air filter at all. There's a lot of engineering and time that go into the filter material that make it actually flow air better than a paper element, and just as effective at trapping dirt and contaminants. Additionally, you've got a ton of surface area on the element itself with a cone style filter, as where the stock air filter sucks through that tiny opening in the air box. That also does a lot for additional flow.

As for the "drop-in" K&N type filters that go into the stock airbox, they may flow a little better, but really the only measurable benefit would be to your wallet... A $15 paper filter will have to be replaced every so often depending on driving conditions. A $40 K&N can be cleaned, re-oiled and it's as good as new again as many times as you want to do it.
 
One problem with the K&N filters is that it's easy to over oil the filter then the extra oil gets drawn into the intake and fouls your MAF then your car runs like crap.
The oil is red which helps you see it but oiling it properly can be tricky.
 
Answer.....aFe Dry flow S washable and not oiled. Cone filter in a box.............

323F_hoodlight_04.JPG
 
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Answer.....aFe Dry flow S washable and not oiled. Cone filter in a box.............

Yes,... But is it rustproof ??

Fe spells iron as far as I remember from chemistry class..

Will it rust when you wash it ?? F√k I hate rust !!

You might not have to oil it to stop dirt but you may have to to stop rust !!?!?

lol
 
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I live in barely winter if any non-salted area and car has been garage kept since 2004. It barely has a layer of road grime underneath it. That's why I posted what I did in the krusty subframe swap thread about not complaining about having to do anything under the car. Those pics sadden me. Wasn't trying to rub anything in tho, just hurts to see great cars crumble...........
 
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