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Another Cowl Induction Idea

scoobyxj

scoobyxj

NAXJA Forum User
NAXJA Member
Location
Coshocton, OH
I Was Thinking Of Drilling A 3" Hole In The Back Of The Engine Compartment Through The Fire Wall Into The Area That The Hvac System Uses To Draw Outside Air From. Running A 3" Tube From There To The Factory Air Box [sealing The Tube Ofcourse], A K&n Panel Filter, And Sealing The Hole In Front [could Even Use One Of Those Inclosed Cone Filters That I Seen On A Thread About Snorkles] . To Make A Cowl Induction Of Sorts. Anyone Got Any Advice On This Idea Will It Even Work Well Enough To Do?
 
A buddy of mine gave me the same idea for running a snorkle instead of having it on the out side of the body. I dont know what all is behind it but I think it could work tho. Maybe someone else has done it.

Where abouts in Ohio are you located?
 
sombody has done it, and I just saw it the other day, but I can't seem to remember where. I think it was on jeepforum. I was doing a search for air intakes. Maybe I can find it, but it was just as you said.
 
I've also been looking hard at the cowl area as a possible source of cool air. On moving vehicles the base of the windshield is a high pressure area, which is why the air inlet for the interior is located there. If you remove the plastic cowl grid, you'll see that the only thing inside that space is the wiper motor and transmission. It's a bit tight on the driver's side firewall, but the passenger's side is fairly open. Remember that the hole doesn't have to be reound (think oval), even thought that's easier to cut. I've got a wrecked XJ that I'm going to operate on before dragging the carcass off to the bone yard, so I'll report back with details.
 
I used central vac hose.
This shot is with the wiper fluid bottle removed....it fits back in but it's pretty tight with the hose there.

http://community.webshots.com/photo/64838123/64839111JULIMS

Where it goes into the airbox
http://community.webshots.com/photo/64838123/64838992vGJFZg

The 3" PVC pipe I have at the front of my airbox...a screw in 3" PVC pipe plug goes in there when I go through deep water. With the plug in my truck breathes solely from the cowl area.
http://community.webshots.com/photo/64838123/64838900UcKYsZ
 
I've also thought of that idea, but doesn't water get in there when it rains? Isn't that why the stock inlet is inside the fender, and the snorkels inlets face down? Might be a dumb question, but curious.
 
scoobyxj said:
I Was Thinking Of Drilling A 3" Hole In The Back Of The Engine Compartment Through The Fire Wall Into The Area That The Hvac System Uses To Draw Outside Air From. Running A 3" Tube From There To The Factory Air Box [sealing The Tube Ofcourse], A K&n Panel Filter, And Sealing The Hole In Front [could Even Use One Of Those Inclosed Cone Filters That I Seen On A Thread About Snorkles] . To Make A Cowl Induction Of Sorts. Anyone Got Any Advice On This Idea Will It Even Work Well Enough To Do?
Click to expand...


Do You Always Capitalize The First Letter Of Every Word?
Billy :)
 
JeepFreak21 said:
Do You Always Capitalize The First Letter Of Every Word?
Billy :)
Click to expand...
It'S beTter thAn caPitalizing thE thIrd leTter of evEry woRd, buT it'S stIll a maJor paIn in thE buTt.

(Back to normal type...)
HEX-J said:
I've also thought of that idea, but doesn't water get in there when it rains?
Click to expand...
I've been wondering the same...
 
On my setup the hole going into my cowl area is actually on a downward facing angle. The cowl area also has drains in it but just to be safe I made the hole up and inch from the bottom metal of the cowl area.

For rain to enter the tube it would have to make it through the cowl grates...and then curve back up into the intake hole. On my vehicle one side of the cowl vent is actually non perforated so the chance of water entering is probably less than the stock intake location.
 
Noise can be a big factor too. I ran a flex tube from my home made air tube into a 3" hole through the cowl on the passenger side. Major noise with any application of thottle pedal. If you route from the silenced factory air box, it may not be quite as bad. This duct space feeds directly into the heat & air vents so the noise has a great path to the interior.

I have duct tape over the 3" hole at the moment, but haven't given up on the idea.
 
I did a simliar mod, I ran 2" plumbing pipe from the back of the stock airbox into the HVAC compartment (updated from when I posted pics back a while ago).

I like the mod, it gave me a little better throttle response and SEEMS to allow for better air flow at full throttle. I have it selectable so I can open or close the factory airbox intake and my snorkle. I'm running with both open now for the airflow. Also I noticed since mine is a solid pipe and that it essentially points right at the driver's seat, I can hear my engine sounds better, also it somehow altered the flow in a way to lower the pitch of the exhaust coming from the Flowmaster. I think it sounds REALLY cool now but it might annoy you if you want a quiet ride.

As far as rain coming in, I've had no problems. I figure that since the rain doesn't poor through my heater vents that there must be some drain holes in the vent conpartment that will drain the water out before my snorkle sucks it up.
 
question sort of for the subject... which would be better for a daily driver and weekend wheeler, a K&N FIPK kit or just their replacement air filter. I want more power but i'm afraid that that FIPK will get wet if i go through a creek. thanks :banghead:
 
XJ667 said:
A buddy of mine gave me the same idea for running a snorkle instead of having it on the out side of the body. I dont know what all is behind it but I think it could work tho. Maybe someone else has done it.

Where abouts in Ohio are you located?
Click to expand...
im in coshocton [page/square 60 in the ohio atlas & gazetteer if you have one]. looked up brigeport with 3 listings which area are you in?
 
XJZ said:
Scooby:
Any chance you work for a newspaper or magazine?
Click to expand...
no i dont i make car mats at a local factory uf you have any mats that have the letters PPI on the back then they came from us [ mostly ford and chevy stuff though i think we made the mats for the ZJ and first generation XJ's]. btw look closely at my spelling id never make it :eek:
 
Bender said:
I used central vac hose.
This shot is with the wiper fluid bottle removed....it fits back in but it's pretty tight with the hose there.

http://community.webshots.com/photo/64838123/64839111JULIMS

Where it goes into the airbox
http://community.webshots.com/photo/64838123/64838992vGJFZg

The 3" PVC pipe I have at the front of my airbox...a screw in 3" PVC pipe plug goes in there when I go through deep water. With the plug in my truck breathes solely from the cowl area.
http://community.webshots.com/photo/64838123/64838900UcKYsZ
Click to expand...
that is kind of the idea i had i haven't pulled the cowl cover off yet so i dont know what it looks like in there was thinking about mabey trying to go in on the pass side [ which ever side opposet from the hvac intake ] sealing off one side from the other and eather drilling many small holes on the pass side or trying to find a new perferated [ like some of that black plastic gutter guard ] material to use as a grill although i dont think ill want the wiper moter getting soaked every time it rains
also does anyone know how much space is between the valve cover and hood when it is closed [4.0 2kxj]
and another question has anyone ever done a test on weather or not a smooth pipe vs a not smooth [like the factory one with ribs in it ] will gain any horsepower?
 
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