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Discussion Starter #1
The K&N conical filters have been used in all of the cars in our family. I would not say that it increases more than 5 to 10 hp, especially if it is not install in conjunction with the exhaust and/or chip modification. For a 240 hp MDX, the percent of horsepower increase is minimal. However, in day to day driving, it does reduce the engine lag, and improve the throttle response.

So, for those of you who can get past the cost, noise and the actual horsepower gain debates, don’t mind taking your car apart, here is what a “poor-man” conical K&N filter installation would look like.

First are some disclaimers to the installation:

1. There is no K&N cold air box kit presently available for the MDX to install with the conical filter. All brackets, elbow and air box partition parts would have to be retrofit or fabricated. You will have to be creative for now if you don’t want to spend a lot of money on marginal horsepower gain.

2. There is no hard data on how many horsepower increase with this installation, although it does give a quicker throttle response due to reduced air intake restriction from removing the resonator box.

3. The car will be a little bit noisier because the air filter box is removed to make room for the cone filter and the air intake resonator is removed to provide maximum airflow. The air intake sound dampening is no longer available, but the noise is no worst than the wind noise.

4. Not sure if it voids any warranty, but the installation is reversible.

Since there is no after-market conical filter kit for MDX available, prepare to make you own. Parts used here were select for their availability. The K&N High-Flow Air Filter part # RE-0870 ($42.99 plus S&H from Jeg’s) was used for this installation. It is a 4” diameter input, 9” long taper cone filter.

You will need one 4” hose clamp and one 3” diameter 90-degree elbow. (A $3 PVC/ “stainless plastic” plumbing elbow would do the trick, you can also get a can of chrome spray paint while you are at the store). A metal L-bracket would need to be fabricated to secure the elbow and air filter assembly to the car. Eventually, a cold air box/partition will be made to separate the cold intake from the adjacent hot air generated from the engine in order to maximize the performance. Since this is a work in progress, the cold air box is not yet been designed and installed. For now, the battery gives enough separation between the engine and the air filter, and you can feel the difference already.

Step 1: Remove the air cleaner/filter box. Leave the factory spring tensioner on the air hose. (Reuse the rubber mounting bumper and bolt from the lower air cleaner box for mounting the K&N air filter later).

Step 2: Remove the front bumper (download the trailer hitch installation from Tim/Hondacuraworld to see how to remove the front bumper).

Step 3: Remove the air resonator (this is located behind the front bumper at the driver side).

Step 4: Install the K&N filter onto the 4” diameter end of the PVC elbow and the 3.5” diameter end of the elbow mounts to the air intake hose.

Step 5: Use an approx. 6-inch long 90-degree steel L-bracket, cut one leg down to 1”. Drill a 1/4” hole on the end of each leg. Weld a ¾ “ L x ¼-20 stud onto the 4” hose clamp for the air intake hose.

Step 6: Attach the 1” leg of the L bracket with the rubber bumper and bolt (from the stock air box) to the car. Attach the 4” hose clamp to the air hose and secure to the 6” leg of the L-bracket through the predrilled hole.

Step 7: Check to make sure the air filter does not rub against any part of the engine bay. Rotate it upwards if necessary. Tighten all hose clamps.

Step 8: Reinstall the front bumper.

You will feel the difference when you step on the gas pedal. The power is available more freely without flooring it. There is no noticeable gas mileage change.
 

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Discussion Starter #2
Step 1 after removing the stock air filter box:
 

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Step 2 after remove the front bumper. Note the resonator box at the lower left hand corner of the picture.
 

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Step 3, this is what the resonator box looks like.
 

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Step 4 to connect the cone filter with elbow.
 

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Discussion Starter #6
Steps 5 & 6 is to fabricate the L-bracket and secure the assembly to the car. (Making the L-bracket is a bit tricky...)
 

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Discussion Starter #7
Step 7, final adjustment before reinstall the bumper.
 

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Crazed-

First, really nice job on the photos and posts....

[soap box on]
Now my 2 cents:

One, you WILL HAVE LESS HORSEPOWER at WOT in summer driving conditions. For every 11degree F increase in intake temp, air density drops by 1% This is simple physics. You WILL loose HP as compared to an intake system that pulls in ambient. Air temps under the hood near the radiator can be 20-40+ degrees higher than ambient. (2-4% in density is 5-10 HP, if I recall correctly)

Two, should you have engine/injector/MAF problems, Acura will void your warranty. (As well they should, given the lower filtration efficiency of the k&N). Of course, every time you bring it in for service, just put the old setup back on.....

(I'm not a believer, so I just had to have this caveat somewhere in this thread...too bad K&N doesn't actually post real controlled dyno data on their products...)

[soap box off]

Ard

PS Did you do any runs (like 0-to-60 or 40-to-70) before and after to compare times?
 

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ardvarkus said:

Two, should you have engine/injector/MAF problems, Acura will void your warranty. (As well they should, given the lower filtration efficiency of the k&N). Of course, every time you bring it in for service, just put the old setup back on.....
Ard,
I agree, the service dept. will likely look at the conical setup with concern especially if you bring the car in for the problems you mention.
But the installation of a 'standard' K&N filter in the air box in no way voids your warranty. At least based on experiences I have had with dealers.
The only problem with the cited installation is reversing it. Not too easy if you have to remove the bumper again. I never realized what a convoluted path Acura developed for the intake. It seems to be over-engineered. On my lowly Villager Nissan used tuned resonators which branch out from the air box and work on canceling resonances, there are no obstructions or bafflles. They maintained a relatively short and direct path to the fender well for cooler air. The beauty of simplicity.
There is some evidence to suggest the filtration of the K&N when new is not as efficient as when it actually builds up a film of dirt as miles go by. But it reaches a point where it continues to filter very efficiently while offering much less resistance to air flow and virtually never choking off the flow as a standard would with 'too many' miles on it. It's efficiency continues up to at least 40,000 to 50,000 at which point a cleaning and reoiling is recommended. They have served me well with more than one vehicle, and all my vehilces were well over 100,000 mles with no symptoms related to excessive engine wear.
 

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K&N fipk is used by Jeep Grand Cherokee as part of Mopar Performance upgrade. It uses a single 4"ID x 8"L cone filter. Mopar claims 26 to 32 rear wheel horsepower, I personally I did not get that w/ my G-tech dyno. As far as Daimer Chrysler is concerned, K&N filter is reliable enough for it to be covered under Jeep's warrenty. And Mopar would not put it in their catalog, if it did not meet their performance claim.

By the way, MDXCrazed, could you make another setup for me? I don't have a welder to weld the stud on the hose clamp. I like your simple setup of having the filter higher up in the engine compartment than having the filter in the bumper, where it could easily get wet.

MidnightGarage
 

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That's a good point, as I noticed GM also offers a K&N optional kit for some models like the Grand Prix SSE.
I would agree most of the improvements seem to be subjective or 'seat of the pants'.
Although some hot rod publications have shown numerical gains due to the increase in air flow. There have been numerous articles in performance magazines (cars & boats) where the K&N is almost an automatic add on. It's robustness over paper would certainly make it an advantage for rally, baja, and marine use.
I can't say I have seen a study that has shown increased cylinder wear due to less filtration of harmful silicates, etc.
 

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DaleB said:

I can't say I have seen a study that has shown increased cylinder wear due to less filtration of harmful silicates, etc.
The old double negative: If there is no study that shows this, that DOES NOT mean that it doesn't do it! (Really, why would ANYONE want to do such a study?)

I'll also say that not having much, if any, published dyno data on HP improvements does not mean it doesn't occur.

I admit that it may increase airflow, but how will that translate to real HP? Especially with under hood air temps.

And keep in mind that "daimler chrysler" doesn't spec K&Ns for their S class, do they?

As wtih any mod, know what the pros and cons are, think critically, and proceed with due care.

Ard

PS Midnight- What did YOU get with your G-tech dyno?
 

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Discussion Starter #13
Ard-

The cold air box design is in the work to address the temperature concern. Right now, the weather is cool enough, and there is sufficient amount of air circulation from below the bumper and behind the headlight to have hot air reducing the horsepower.

Our MDX is too green to do WOT heavy duty 0-60 run or dyno, it’s only got 2200 miles on it when this filter was installed. Since then, I have driven 100 miles happy miles with the new filter and I just love the extra peppy power. Eventually, I will do a dyno comparison test just for my own curiosity. It is really not too bad to remove couple screws and clips to take the front bumper off and reconnect everything. For now, the enhanced performance is good enough for me.

As stated before, I do not have the hard number on horsepower gain besides just “butt” dyno it. Would it make any difference if I claim that this will increase 18 to 32 hp? There will be believers and non-believers out there. This is not a commercial or a live testimony for K&N filter. Just an FYI on what you can do for $60 and an hour of work. This easily ranks as one of the “best bang for the buck” simple modification.

As for voiding the warranty, you will have to assess the risk. But I have never have a dealer able to claim that due to the K&N filter installation, and I have never bother to remove the installation when I take the cars in for service. In fact, the installation procedure is the same as what Jeep would have recommended for a Mopar cold air performance kit installation. Also, I owned an Integra before with this modification, and the Acura dealers have never questioned it.

Therefore, for those of you who is all done with the exterior modifications, let’s have some fun with what’s under the hood. Anyone going to “butt” dyno this setup and throws us a hp number?

BTW, Midnight-

What kind of garage do you have without a welder, a metal bender and a drill press to make that L-bracket? :D

Let me know how many out there is interested in this set up.
 

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MDXcrazed said:



Let me know how many out there is interested in this set up.
I am interested in knowing what makes up that Acura box at the bottom? ( I am still in line waiting for my X to come in!)

I used to do mods to air boxes. I did it on a couple of Fords. They were so easy. The box had an inverse funnel (to reduce the air's velocity resulting in less noise) that just snapped out! Like it was meant to be removed!
I would take foam and stuff it in the box end to reduce any tendency to resonate due to the square shape and also due to the unpadded plastic. But left the air route totally unobstructed. It worked great. Just got a 'whoop' when I really opened the throttle hard, but that was kind of cool!
 

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How bout installing one of these..


I am about to go into fulll production, and have about 15 units sold to 99-02 Odyssey owners! We have dnyo'd it at 17+ hp at the wheels!

I just had the discussion about 'homemade' intakes on the ODYCLUB forum....guy was adament about his working :) well, after discussing it with a few Honda guys, and convincing him otherwise, you won't see many HP gains....the PRI intake was made for horsepower!

until April 15, 2002 I'm selling these at a discount....200.00 plus shipping. retail was to be set at 289.00, but i'm looking at getting these out to the public!

they will work on the MDX as it's the same setup as the 02 ODY.

need more info email me. or check out www.odyclub.com forums in the performance mods section.

thanks guys!
 

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Discussion Starter #16
Love to show you the schematic of the MDX Intake Air System Diagram as in the Service Manual. Unfortunately, my scanner has been down, so here is a photo of it. The easiest thing to do without modifying the filter and intake system is to just remove the resonator box. When you get your new car, drive it stock for awhile before modifying it. That way, you can feel the “before” and “after” difference. Also, if you like to tinker, buy a Service Manual, so at least you will know what you broke or where everything is.

The so-called “home-made/poor-man” filter set up has worked quite well. It is a real joy driving the car now with the newfound responsiveness. I have a lead foot and love to drive fast. This setup has definitely made a difference. The major advantage is that it has a really short and large diameter intake air pipe to move more air than a long narrow tube. The filter is high up enough to avoid sucking in water when hit a puddle and damage the engine. Due to the opening behind and below the headlight, the system gets a ram air effect, hence creating a high-pressure zone of colder air than the rest of the engine. Note the above photo in Step 7, the filter is fully expose to incoming air through the grill.

The PRI design for Odyssey uses a thin narrow tube with flexible joint as the air intake pipe, it will need to be modified to fit the MDX’s engine compartment. MDX seems to have more room than the Odyssey to accommodate a cone filter next to the battery. Otherwise, A photo of the actual filter and its position, as well as how this set up will look inside a MDX will be helpful.
 

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Starting to see some real engineering...driven by data it sounds like.

Tricked: Did we dyno the PRI set-up with a closed hood in summertime conditions??? Or was it winter, 60 degrees, hood up and fan cooling the whole front end? If you get 19 HP in a closed hood 90 degree F ambient condition (which is likely 120 underhood), I am impressed. That probably translates to 0.2 sec on the 0-60 time.

I am heartened that 'crazed admitted that for summer driving you need to do something else ("Right now, the weather is cool enough, and there is sufficient amount of air circulation from below the bumper and behind the headlight to have hot air reducing the horsepower. ") How many folks don't know about the actual loss of HP with hot air, and wind up leaving it in all year?

Heck, we're all big boys, just know what you're REALLY doing when you do these mods... just because the racers use something doesn't mean it'll work on your vehicle you drive every day in all kinds of suboptimal conditions.

Nice to see pretty hardware being made, though....

Ard


PS Now, come up with a new PCM for this baby, and you're talking a different story...
 

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This is a COLD AIR INTAKE! it should EASILY fit into the MDX engine bay as the filter, AFE, is behind the bumper, in front of the front tire.

I didn't screw around when making this either.....the pipe size, bends, filter...everything was picked and designed to provide maximum power gains.

The dyno was run inside, about 70 degrees, hood closed.....when it's hot out you may not get as much hp...but being a "ram" air type setup, you will ONLY get outside air to it. The polished stainless should also help in hear reflection on the inside, and the piping is heavy guage...this is not cheap stuff.

and the HP gains are night and day noticable! "MY" butt dyno would be more than happy with the added HP, that is if I was normal :)

we are also going to work on a PCM replacement :) when the twin turbo's go in we'll be doing datalogging and self mapping :)

join my list at yahoo groups to keep tabs: [email protected]

next on the list?

-stainless exhaust (cat back w/convertor) April 15
-twin turbo setup - by September 2002
-Carbon goodies
-big brake kit

be wary of the next canyon stone silver ODY you see....it may just be me :)
 

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ardvarkus said:
And keep in mind that "daimler chrysler" doesn't spec K&Ns for their S class, do they?

Ard
Ard, want to know why? It is because the MB engineers did do a long term study and tests using the K&N filters and what they found was that the filter did let in more air. HOWEVER, at an expense of larger dirt particles. As a result, this is deterimental to the long term life of the vehicle, and also the reason why the MB engineers do not recommend it.
 

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It appeared to me on 'Tricked's mod the filter is not a K & N but some sort of paper cone filter.. am I right?
The visible filter is on the Odyssey forum I believe.
______________________________________________________________________________________________
rd, want to know why? It is because the MB engineers did do a long term study and tests using the K&N filters and what they found was that the filter did let in more air. HOWEVER, at an expense of larger dirt particles. As a result, this is deterimental to the long term life of the vehicle, and also the reason why the MB engineers do not recommend it.
______________________________________________________________________________________________


Anyway, would be interested in the MB study if available. I am sure there are a lot of expensive machines, like Porsches and Bimmers running around with K&N filters. Not promoting a product is not the same as disapproving it's use.
 
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