Topic: cowl intake

[huntingbuck101]

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.

[Jeffy]

Well, snorkels are decent cold air intakes even with the extra distance the air has to travel.

[JeepManMarc]

Cowl induction on a Jeep?      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.

[pyfighter2000]

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.

[Jesse-James]

Do the Hummer snorkel......

[Jeffy]

Do the Hummer snorkel......

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.

[Jesse-James]

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.

[Jeffy]

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...

[j-freak153]

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...

[Jesse-James]

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...

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.

[chrisfranklin]

Jeep Submariners    . 

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. 
 

[Jeffy]

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.)

[chardrc]

  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.

[Jeffy]

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.

[chardrc]

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.