replace snorkel with cone filter

[ChrisZang]

I was wondering if anyone ever tried to de-snorkel and put a cone filter in the now empty space where the snorkel was and - yes of course - get rid of the internal air filter

This way you'd have the best of both worlds: cone filter with more air flow + but the cold filter is outside the engine bay = real cold air intake

Might be a tight fit though...

[CJ_Boxster]

Thats an interesting idea that inspires me, you could use the Snorkel as a mount... just chopping off most of it and using the base as a mounting point for the new filter HOWEVER you would get the filter wet when washing the car... and while water will not splash into the airbox.. it would atomize when the engine is started and sucking in air and that mist of water will land on the MAF if the filter isnt dried first.

Also, i think alot of the cool intake sound would be canceled out with a filter on the end of the assembly cause i beleive some of the noise is part of an echo which come from inside the void of which the old snorkel use to occupy (the gap between the scoop on the body and oval opening of the airbox).

[j.fro]

Interesting idea, but to really see some benefits, you'd need to do a bit of work inside the airbox. The worst part of the stock airbox is the convoluted tube that runs from the snorkel to the air filter. It directs air in,forward, up, then back. As well, it has the narrowest cross section of any part of the intake pathway. The EVO and other aftermarket intakes eliminate all of this, making airflow more efficient. To keep the cold air part on an EVO, simply extend the sides of the new box so that they seal against the engine cover. I used foam pipe insulation for this.
Garage innovation is a great thing!

[CJ_Boxster]

One more thing i thought of that might be a problem... in the airbox there is a water drain with a feltpad liner, if you place a filter before the drain, i think air will probably get sucked up from there unless its plugged.

[Most_Wanted]

Thread revival. I feel this topic didn't get enough responses.

Has anyone attempted this sort of modification? I was thinking you cut the "tub" piece off the snorkel and attach a filter with a oval design fitting. Finding the appropriate sized filter could be a challenge. If j.fro can reiterate on what makes the 986 airbox restrictive. I didn't understand clearly. Difficulty in fitting a 987 airbox is the only thing swaying me away from the mod. This could be a nice alternative to the 987 airbox.

[j.fro]

The pipe that runs between the snorkel and the actual airbox has at least 3 90 degree bends. As well, it has a pretty narrow cross section.

I had to do some significant mods (like get rid of the convertible top and the rain trays), but I've got a cone air filter and the MAF now located in a box outside of the engine compartment, just inside of the air intake. Using Dash Command, one improvement I regularly see is that incoming air is only a few degrees warmer than the ambient air temp. With the airbox/MAF inside the engine compartment, you'll get readings significantly higher.

[Quadcammer]

987 airbox is the way to go. I just installed one and its crazy how much bigger it is than the stock one. The stock one might be just ok for a stock 2.5, but beyond that, its tiny.

[Most_Wanted]

J.fro that looks real good. I'm surprised to see a cone filter actually fits in there. Is that a Spectre cone filter? Do you have a part number by chance? I think i understand the restriction of the 986 airbox now after reading your post & image searching. I thought only the cone filter was what improved the 987's airbox induction. I'm considering my own custom intake tubing now. The foil wrapping is a nice touch.

[Quadcammer]

Originally Posted by Most_Wanted

J.fro that looks real good. I'm surprised to see a cone filter actually fits in there. Is that a Spectre cone filter? Do you have a part number by chance? I think i understand the restriction of the 986 airbox now after reading your post & image searching. I thought only the cone filter was what improved the 987's airbox induction. I'm considering my own custom intake tubing now. The foil wrapping is a nice touch.

The 987 filter is huge, the snorkel is easily 2.5x the size of the puny one in the 986, the snorkel hole goes directly into the airbox with no convoluted turns, and the maf sampling tube is bigger. Its just superior.

[j.fro]

I think that filter with the chrome endcap was a spectre... I've swapped it for a larger filter now that I believe is AFR. I'll have to check.
The filter fits, but be aware that I also removed the "tunnel" that the old snorkel lived in.
The 987 airbox is indeed a nice piece and a big improvement over the 986 box, but it's not exactly plug and play. The MAF housing is 996 sized. To use the 987 airbox, you'll need to run a 996 tune, get a custom tune, or somehow splice in a 986 sized MAF housing. Without doing this, the car will run dangerously lean.

[Gelbster]

i.fro has a great concept because he is moving the filter to a cooler location and using empty space.
I did a similar,less intrusive project and would mention another benefit of removing the airbox.
If you have to work on Bank2 with the engine in the car ,even the regular airbox is extremely obstructive. The larger 987 is worse. With no airbox you can access the injectors and even remove the cam cover to replace lifters.
Before you decide on doing this ,just read up on how to remove the airbox. As an indication of the difficulty, often it has to be broken into pieces to extract it.

[Most_Wanted]

There's a vid on youtube of someone splitting the airbox in half at the seams with a flathead. Claims it takes only 10 min. I'm thinking i'd run tubing into the snorkel area and fabricating a plate to seal it from the engine compartment. I already have the 997 tb/plenum so after this i'll be mostly satisfied with the intake side of things.

The 986 maf housing is detachable from the airbox? Or does it have to be sawed off?

[Gelbster]

Before the Demolition begins, I suggest you investigate the void between the inner and outer wing. This is where the original snorkel is fitted. The space is an irregular trapezoid.
I used it for the filter media(Unifilter).
Then you need to source the rest of the ducts,elbow,adapters and connectors to reach the MAF
You will need to fabricate a plate to fit over the hole in the inner wing .The plate needs an integral flange to connect to the largest elbow that will fit.
There are details in other Threads if you Search.
If you fail to get a perfect seal on the entire system and good filtration you'll get MAF contamination codes/faults.

[edc]

If the intake routing is still the same why would it make a significant temp difference to intake air temps where you place the filter? The air still enters from the same location and follows the same route.

[Gelbster]

Originally Posted by edc

If the intake routing is still the same why would it make a significant temp difference to intake air temps where you place the filter? The air still enters from the same location and follows the same route.

Heat soak in slow-go traffic.
But agreed ,the air moves so fast it does not 'have time' to pick up much heat normlly.
Thant is why I noted the accessibility advantages of deleting the airbox and using the inner wing void as an air filter case.
Some people just love the CAI concept but don't research the extent of any(small) advantages.

[edc]

Originally Posted by Gelbster

Heat soak in slow-go traffic.
But agreed ,the air moves so fast it does not 'have time' to pick up much heat normlly.
Thant is why I noted the accessibility advantages of deleting the airbox and using the inner wing void as an air filter case.
Some people just love the CAI concept but don't research the extent of any(small) advantages.

And heat soak has a detrimental affect on peak power ... ? Which you won't use in urban traffic.

[Gelbster]

Urban ? who said urban?
The main advantage is accessibility. Wow, I said that 3 times now. That depends on how much serious wrenching the engine ever needs on Bank 1
The DME adjusts for intake temp.

[edc]

You used the term slow-go which I interpret as urban/in town. In any case I think we converge on the same point perhaps that moving the filter may not be a panacea that some may think it is. As already pointed out there are quicker and more advantageous things to do intake side whether that be 987 airbox or a smoother intake run etc.

[Gelbster]

Re-positioning the thermostatic switch for the engine compartment fan also may help slow/go heat soak issues.
The issue is most noticeable when moving off after idling in heavy traffic at high ambients.If the engine compartment fan comes on at lower temps ,it may help