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General Forums => The Mess Hall => Topic started by: huntingbuck101 on March 29, 2007, 08:48:12 PM

Title: cowl intake
Post by: huntingbuck101 on March 29, 2007, 08:48:12 PM
thinking of making a cowl intake on my tj. In theory it seem easy, plug air horn hole in the stock air box and run tubbing from back of the box to a hole cut in the center of the cowl. but would it be worth doing? wold rain make it's way to air box while driving? would you have forced air or ram air affect from air hitting the windshield and pushing down into cowl to aid in performance? would it just add to the maze the air already has to go threw to get to the throttle body? I did a search on it and seen the tech writeup on it so I know it can be done but would it give similar performance gains as a under the hood cold air intake or snorkel? also I would use a K&N dropp in filter with it and maybe a cowl scoop.
Title: Re: cowl intake
Post by: Jeffy on March 29, 2007, 08:49:55 PM
Well, snorkels are decent cold air intakes even with the extra distance the air has to travel.
Title: Re: cowl intake
Post by: JeepManMarc on March 30, 2007, 09:50:32 AM
Cowl induction on a Jeep?   :clap: :roflol:  I come from a drag racing background..   Turbo = forced induction, Super Charger = forced induction, Nitrous = forced induction, along with a few other forms of methanol or alchohol but in essence a cowl hood is just a way to get air more efficiently, the air from the windsheild thing may help you get slightly more air, but defenitely wont be noticable.  The gains you could expect wouldnt be worth near the work it would take to do it and do it right.
Title: Re: cowl intake
Post by: pyfighter2000 on March 30, 2007, 11:32:55 AM
Yeah i did it and not really any performance gains or mpg gains.  I just did it to keep my air filter clean of all the mud and crap that kept getting sucked in through the air horn.  Works really good i have to say.
Title: Re: cowl intake
Post by: Jesse-James on March 31, 2007, 01:05:33 PM
Do the Hummer snorkel......

(http://thumb11.webshots.net/s/thumb4/7/98/92/85979892YLzrGR_th.jpg) (http://sports.webshots.com/photo/1085979892042281111YLzrGR)
Title: Re: cowl intake
Post by: Jeffy on March 31, 2007, 02:25:47 PM
Do the Hummer snorkel......

(http://thumb11.webshots.net/s/thumb4/7/98/92/85979892YLzrGR_th.jpg) (http://sports.webshots.com/photo/1085979892042281111YLzrGR)

Wow, that's an awful place to put it.  The snorkel is an attachment that moves the stock intake higher up.  But since that's right in the middle it would be like having chimney there.  Not to mention it also means you'll never be able to lower the windshield.  If H had to choose, I'd go with monsterslayers setup and have the intake at teh end of teh cowl cover.  At least it's not right in the middle although it will won't allow you to lower the windshield.
Title: Re: cowl intake
Post by: Jesse-James on March 31, 2007, 04:22:11 PM
it would be like having chimney there.

Not sure what you mean by that.....as far as not putting the windshield down many people don't care. It is an option to us who wheel where trees are the enemy of traditional snorkels. Myself, I have bigger fish to fry before I think about a snorkel but may consider something like this when I do.
Title: Re: cowl intake
Post by: Jeffy on March 31, 2007, 06:08:50 PM

Not sure what you mean by that.....as far as not putting the windshield down many people don't care. It is an option to us who wheel where trees are the enemy of traditional snorkels. Myself, I have bigger fish to fry before I think about a snorkel but may consider something like this when I do.

The snorkel attachment is a 4" dia tube that sits on the airbox.  The problem I see with leaving the top cap at hood level is that water will splash up on the hood if it's that deep.  If the vehicle is moving at a constant speed there is a depression which is caused by the bow/front of the Jeep.  This depression allows for the Jeep to go deeper then the height between the airbox and the ground...

(http://www.adventureaccessories.com/accessorypics2/performance/snorkle1.jpg)
Title: Re: cowl intake
Post by: j-freak153 on March 31, 2007, 07:06:55 PM
that is what i'm gonna do...on the cowl but up a little higher than the hood level like 2 or 3 inches then the cap...
Title: Re: cowl intake
Post by: Jesse-James on March 31, 2007, 11:46:34 PM

Not sure what you mean by that.....as far as not putting the windshield down many people don't care. It is an option to us who wheel where trees are the enemy of traditional snorkels. Myself, I have bigger fish to fry before I think about a snorkel but may consider something like this when I do.

The snorkel attachment is a 4" dia tube that sits on the airbox.  The problem I see with leaving the top cap at hood level is that water will splash up on the hood if it's that deep.  If the vehicle is moving at a constant speed there is a depression which is caused by the bow/front of the Jeep.  This depression allows for the Jeep to go deeper then the height between the airbox and the ground...

(http://www.adventureaccessories.com/accessorypics2/performance/snorkle1.jpg)

So you're saying the stock airbox is better than having it on the cowl? I don't buy it. Water is going to splash on on it, that is why it's intake is on the bottom of the assembly. Gravity isn't going to allow it to take water the way you're thinking. I don't think it will take on any more water than a safari type snorkel. Raising it a couple inches wouldn't hurt, but it's still a logical choice for those that battle trees.
Title: Re: cowl intake
Post by: chrisfranklin on April 01, 2007, 01:24:51 AM
Jeep Submariners :lol:   :fish:. 

Nah, the snorkel's cool.  But, I'd need one maybe once or twice, at best, though. Probably like a winch for most guys.   But, when you need it, you need it.

I plan on avoiding a need for it, though. 
 
Title: Re: cowl intake
Post by: Jeffy on April 01, 2007, 01:53:17 AM
So you're saying the stock airbox is better than having it on the cowl? I don't buy it. Water is going to splash on on it, that is why it's intake is on the bottom of the assembly. Gravity isn't going to allow it to take water the way you're thinking. I don't think it will take on any more water than a safari type snorkel. Raising it a couple inches wouldn't hurt, but it's still a logical choice for those that battle trees.

I'm not sure if better is the right word.  Perhaps no better.  Like I said, the wave will have a trough at the backside of the wave which will give you a little leeway.  If you're hitting the water fast enough or it's deep, the peak will rise higher then the baseline.  Which would then go over the hood.  (The front of the Jeep would still slow the progress of water.)

In any case my complaint isn't with the design as much as where he's got the input located.  It just looks bad.  The other thing I'm not really keen on is that there is no airbox to speak of.  He has what looks like flex hose going through the firewall into the cowl space to the cut off stock intake.  That would mean his filter is under the cap.  So if water did get into the intake, there is no holding area, it just gets sucked into the engine.

The other setup I've seen, which I believe was the first, had a airbox under the hood still.  This will at least hold some water back.  This is why ARB uses the stock airbox.  The input is low in the box but the output for the intake is high up.  This means the box would need to fill some ways before water gets ingested into the engine.  It's acts like a trap can.

I've seen some bad PVC and some good PVC home jobs.  Still without sealing up the diff, transmission, transfer case, distributor, PCM, raise the exhaust, etc...  having some positive pressure might even be an idea.  Although the other use for a snorkel is for high dust areas.  In that case you're trying to grab clean air where ever you can.

Another option is to go with the non-permanent setup like the Military Jeeps used.  You could have the intake go through the hood and attach the hose from the outside. (I think this is what they might be doing with the CRD Militilary JK's.)

(http://www.armyjeeps.net/M170Amb/2005_0414M170Jeep0009.jpg)
(http://www.armyjeeps.net/M170Amb/2005_0414M170Jeep0010.jpg)
Title: Re: cowl intake
Post by: chardrc on April 01, 2007, 11:17:55 AM
 :beer: :bow: m38.... interesting fan shroud behind the fan to keep it from splashing water everywhere.. but then how does the motor cool down it you cant move air across the radiator.. unless its a revers fan but then you would still be sol when moving at any speed.
Title: Re: cowl intake
Post by: Jeffy on April 01, 2007, 12:12:25 PM
:beer: :bow: m38.... interesting fan shroud behind the fan to keep it from splashing water everywhere.. but then how does the motor cool down it you cant move air across the radiator.. unless its a revers fan but then you would still be sol when moving at any speed.

The M38  is a flat fender based on the CJ-3A.  The M38A1 is based on the CJ-5 but this isn't it either.  This is a M-170 based on the CJ-6.  It has asymmetrical doors which is unique to this model.

The shroud has a hole through the back of it like every other shroud.  It's not closed off.

(http://www.armyjeeps.net/M170Amb/2005_0414M170Jeep0001.jpg)
Title: Re: cowl intake
Post by: chardrc on April 01, 2007, 12:24:31 PM
ow i was thinking m38a1 but ounce again i was proved wrong... hmm that fan should looked more closed off to me than what ive seen before but whatev.
Title: Re: cowl intake
Post by: Jesse-James on April 01, 2007, 01:48:56 PM
I'm not sure if better is the right word.  Perhaps no better.  Like I said, the wave will have a trough at the backside of the wave which will give you a little leeway.  If you're hitting the water fast enough or it's deep, the peak will rise higher then the baseline.  Which would then go over the hood.  (The front of the Jeep would still slow the progress of water.)

In any case my complaint isn't with the design as much as where he's got the input located.  It just looks bad.  The other thing I'm not really keen on is that there is no airbox to speak of.  He has what looks like flex hose going through the firewall into the cowl space to the cut off stock intake.  That would mean his filter is under the cap.  So if water did get into the intake, there is no holding area, it just gets sucked into the engine.

The other setup I've seen, which I believe was the first, had a airbox under the hood still.  This will at least hold some water back.  This is why ARB uses the stock airbox.  The input is low in the box but the output for the intake is high up.  This means the box would need to fill some ways before water gets ingested into the engine.  It's acts like a trap can.

I've seen some bad PVC and some good PVC home jobs.  Still without sealing up the diff, transmission, transfer case, distributor, PCM, raise the exhaust, etc...  having some positive pressure might even be an idea.  Although the other use for a snorkel is for high dust areas.  In that case you're trying to grab clean air where ever you can.

Another option is to go with the non-permanent setup like the Military Jeeps used.  You could have the intake go through the hood and attach the hose from the outside. (I think this is what they might be doing with the CRD Militilary JK's.)

I see what you mean now about the wave engulfing it, and as far as the airbox goes that's a given. Just used that pic for lack of choices.

As far as the military setup, that looks nice. Put it on when you need it, stays away from the trees when you don't. I like it.
Title: Re: cowl intake
Post by: tjsean0308 on October 16, 2010, 04:10:07 PM
Raising the dead here a little bit.  Jeffy, do you still have the pictures you put in this thread way back when? I like the idea of a removable snorkel that would use the stock air box.
Title: Re: cowl intake
Post by: Jeffy on October 16, 2010, 06:05:10 PM
Raising the dead here a little bit.  Jeffy, do you still have the pictures you put in this thread way back when? I like the idea of a removable snorkel that would use the stock air box.
here's a different one with the same idea.

http://www.jeepforum.com/forum/f27/write-up-hummer-cold-air-intake-326040/
Title: Re: cowl intake
Post by: tjsean0308 on October 17, 2010, 11:38:27 AM
Thanks   :thumb:
Title: Re: cowl intake
Post by: Torch_Ind on October 17, 2010, 11:51:09 AM
here's a different one with the same idea.

http://www.jeepforum.com/forum/f27/write-up-hummer-cold-air-intake-326040/

thats cool I have seen people run it to the wiper motor area but that is a nice set up!!
Title: Re: cowl intake
Post by: jfrabat on October 17, 2010, 02:42:46 PM
In all honesty, if trees are a problem for a traditional safari snorkel, just point the intake to the middle of the vehicle, and you will be just fine.  Even down here in Costa Rica, I have had not a single problem with my snorkel and trees (or rocks or water).  I would go this way if I were you, not only because of the nice lines it has, but also because it is a proven method.  But like it has been pointed out already, keep in mind a snorkel does not turn your Jeep into a submarine; you still got to worry about  all the breatehrs (axles, tranny, etc.) and all the electrical (of particular concern is the distributor), and all the electronics (many a jeep has died here becasue the ECU had cracks and the water killed it; in fact, I always take an additional ECU on board during runs just in case).