Re: custom air intake mod *LONG*

["Dave Fournier" <davidf@teleport.com>]

Like an airfoil (aerodynamics), the smother the better.

Dave Fournier
replyto:davidf@teleport.com

-----Original Message-----
From: Patrick Sherman <patrick@volkswagen.org>
To: jettaglx@igtc.COM <jettaglx@igtc.COM>
Date: Sunday, July 12, 1998 10:08 PM
Subject: RE: custom air intake mod *LONG*


>How about the bottom intake of the Airbath and the duct work..
>
>
>Patrick Sherman
>mailto:patrick@volkswagen.org
>1997 VENTO VR6 / Tornado Red / 18K
>"One cannot live on air alone....Add Water"
>
>> -----Original Message-----
>> From: owner-jettaglx@igtc.com [mailto:owner-jettaglx@igtc.com]On Behalf
>> Of cyng
>> Sent: Sunday, July 12, 1998 4:18 PM
>> To: Eric Wang; jettaglx@igtc.COM
>> Subject: Re: custom air intake mod *LONG*
>> 
>> 
>>    I'm going to send this to the GLX list, Eric, since I'm sure
>> that someone there will either be able to make use of this or poke
>> fun at it. I would send it also to the Corrado-Club list, but
>> there's no way that there's room enough for this kind of thing in
>> a Corrado (as I well know from looking at my brother's '92 SLC).
>>    Okay, well, here goes.
>>    It's a simple (in theory) modification, and doesn't necessarily
>> do you any good except at higher speeds or in cooler weather ...
>> but SOME good done is better than none, right?
>>    Your stock airbox has this elbow tube which runs from the front
>> of the airbox into the side fender. There's a big hollow space up
>> there in the fender, kind of closed off by the fender itself, the
>> interior of the engine bay, the wheelwell, and a sort of plastic
>> panel/skirt which makes up its "floor." This is where your car
>> gets its air from. It's not the best of sources, all closed-off
>> like that, especially in a black car like mine where heat gets
>> trapped rather quickly on a sunny day.
>>    So I thought to myself, asking where the freshest air could
>> come from? The front of the car, of course - somewhere before
>> the radiator, somewhere before any body panels, somewhere like
>> the nose of the car. So I took a look. There's not much room.
>> One can't remove one's headlight for legality reasons. I'm no
>> good with saws and such for hacking out a bit of my front grille
>> and making it look nice. So I looked some more. What I found was
>> a series of holes along the bottom of the front side of the front
>> spoiler. There's a hole on either side below the blinkers which
>> has a sort of plastic grille over it. Behind these, on either
>> side, hide your horns. On the passenger's side, attached to the
>> little grille there, is your ambient air temperature thermometer.
>>    I didn't want to mess with removing a horn or moving that
>> thermometer, so I looked some more. In the centre of the stock
>> front spoiler are a few open holes, wide ones. They look good,
>> except for the fact that the radiator extends even that low, and
>> it sits right behind those holes. So forget those central ones.
>> Between, however, the little grille/horn ones and the central,
>> radiator-filled ones, is a pair of smaller holes. The one on the
>> driver's side, which is about 4" wide and 2.5" tall, is, obviously,
>> on the wrong side of the car. The one on the passenger's side, on
>> the other hand, is in a good spot. It's about 3" wide by 2.5" in
>> height, or so. Each is covered by a dummy panel, a thin plate of
>> plastic which clips into and out of place rather easily. Hmmm ...
>>    I'd heard of ram-air systems, and air scoupes and other such
>> kits, but had been unable to find any for purchase. The closest
>> that I could find was a front spoiler available from ND which had
>> these air funnels on either side where your foglights would go,
>> and all that this purportedly was for was to help cool the
>> radiator as well as the brakes. Nothing about any tubes to bring
>> this fresh air up and into the airbox.
>>    So I figured that I'd have to do it myself. Grumbles and such.
>>    Thus, I took out that passenger-side dummy panel and took a
>> peek. Lo and behold, there's a little room there. Not much! But
>> most of space behind the hole is open. A bit of the metal tube
>> which carries collant to/from the radiator is there, but not
>> much of it. I popped the hood and looked down, after removing the
>> airbox. Indeed, there is a tight route through there, between the
>> radiator and the alternator.
>>    I went to a nearby HQ and walked about, an idea in my head. I
>> would need an adjustible, metal clamp (the kind where you screw
>> in a screw to tighten the notched, metal band), some of those
>> plastic baggie ties where you stick one end through a square in
>> the other and pull it tight, some metal mesh, and a hose or tube.
>>    The clamp was easy to find. It's 3"-2" or so, and didn't cost
>> more than a couple bucks.
>>    The little plastic baggie ties were also easy to find, from the
>> electronics department. I found small, black ones (my car is also
>> black, so this was ideal). These are the little things that you
>> use to hold wires together, I suppose, and such things. One end
>> goes through a square in the other end, and the whole thing is
>> ridged, so that, because of a tiny tab in the square hole, you
>> can't pull the thing back through. Cheap, too.
>>    The wire mesh was pretty easy to find as well. I used some
>> "charcoal-black" aluminum screen - the sort you'd put in a window
>> in your house. I did look at the little repair patches, but these
>> were far too small for my purposes, and so I had to buy an entire
>> roll of the stuff. Eight to twelve bucks.
>>    The tube or hosing, on the other hand, was a pain to find. I
>> wanted something at least 2.5" on the inside diameter and not more
>> than 3" in outside diameter. I wanted something flexible enough to
>> be able to be squeezed through a tight space, but tough enough not
>> to collapse as cloth would. I wanted something that would stand up
>> to hot temperatures. This last worried me quite a bit.
>>    I know that my oil temps rarely see 230, but it CAN get damned
>> hot in that engine compartment. So, I looked for something tough.
>> On the other hand, after having driven around several towns all
>> day on a hot day in search of this elusive tube, I decided to
>> check just how hot things did get in that area of the engine bay.
>> Well, my car's a '95, and so it has an air pump. There's a small
>> tube (barely an inch in outer diameter) running from my airbox
>> down to my air pump. This little tube goes exactly where the tube
>> that I wanted to run would go - between the radiator and the
>> alternator. In fact, it's braced against the metal of the alt. I
>> don't know that you have this air pump, but, take my word for this,
>> this little tube isn't what you'd call heavy-duty. It's plastic.
>> It looks a lot like a vaccuum cleaner hose. And it stands up to
>> whatever temps are in that area just fine. After all of this
>> driving, too, that bit of metal coolant pipe down by where the
>> hole in the front spoiler is was definitely air temperature. No
>> risks there, either. These, added to the fact that it's right at
>> the front of the car, where all the fresh, cooling air is, made
>> me lower my standards a bit when I looked for the tube I wanted.
>> That air pump tube ... looked like a vaccuum cleaner tube. Hrm.
>> A vaccuum cleaner tube ... Yeah ...
>>    So, I scurried back up to the HQ in Portland, and looked
>> around some more. All of their plumping tubes (vinyl and such)
>> were too small, or else collapsable. Forget it. I went up to the
>> Home Depot in Westbrook. No luck there, either. I went to several
>> hardware stores. I went to a VIP. I went to a NAPA. I went to a
>> Parts America/Western Auto. None of these places had any flexible
>> air ducting.
>>    Back to HQ. I told an employee what sort of thing I was look-
>> ing for, and he brought me straight to a small vaccuum cleaner
>> section. Slap my palm to my forehead - there it was. A 6' replac-
>> ment hose, 2.5" in inner diameter, rated for heavy-duty,
>> commerical-grade vaccuum cleaners and rug shampooers. Perfection.
>> And only (!) $16.
>>    I ignored my wallet's complaints and bought it.
>>    Here's what I did - pardon my ramblings.
>>    I unplugged my fan, as a lot of this work involves the hose or
>> your hands touching the fan - ouch.
>>    I unclamped my air pump's little tube. I removed the air box
>> from the car.
>>    I unclipped the dummy panel covering the hole just inside of the
>> leftmost, grille-covered hole, behind which hides one horn and to
>> which is attached my ambient temp thermo. It has two clips on the top
>> which you press downwards on, then slide back, towards the rear of
>> the vehicle. It's a pain to work the little panel out from between the
>> front spoiler and the radiator, but it's possible.
>>    From the top, I ran the vaccuum cleaner hose down behind the front
>> of the engine bay towards the ground. This is a pain, because the fit
>> is tight. The hose goes down, behind the fan, in front of the engine
>> block.
>>    Once I had it low enough, about even with the hole in the spoiler,
>> I knelt down and, from under the car (you don't need a jack or lift
>> or stand), kind of pushed the end of the hose into the hole. It's a
>> big pain, getting this through, because the end of the hose will get
>> caught on any number of protrusions. You need to bend the hose some,
>> squish it a bit, to get it through and around these protrusions, but
>> it WILL fit.
>>    With a firm grip on this lower end of the hose, I pulled hard,
>> pulling more slack through from above. It's tight, like I said, but
>> it doesn't hurt anything to pull hard. The hose should be tough enough
>> to take some stress.
>>    With a good half foot of the hose sticking out through the spoiler's
>> hole, I went back to the top end of it to put it in its place.
>>    I forced the hose into a safe place. It squished it some, so it's
>> not a perfect circle in one slightly cramped place, but it's still got
>> the same interior surface area and still lets in the same amount of
>> air. I made CERTAIN that the hose was between the alternator's housing
>> and the front of the engine bay. It CANNOT touch the fan blades. It
>> CANNOT touch the drivebelt. Placement is very important, because, if
>> you didn't get it in just the right place (kind of to the left of the
>> air pump's tube, using that tube as a sort of guide), you could do
>> some serious damage to your fan or drivebelt through friction. Or worse.
>>    With the hose firmly lodged into place, away from the fan and the
>> drivebelt, I moved on to the more delicate parts.
>>    I eyeballed how much hose I would need to let it reach into the
>> airbox, then cut the hose at that point. This is about halfway, so
>> you need at least three feet of hosing to get the job done.
>>    I unscrewed the elbow tube from the airbox and set it aside.
>>    I put the bottom half of the airbox back into the car (leaving the
>> rubber doughnuts out for now - this is just for better fitting). I
>> fed the top end of my hose into the same hole in the airbox that the
>> elbow tube once had been attached to. The fit is imperfect, since the
>> hole in the front of the airbox is about 3" and the outer diameter of
>> my hose is about 2.75". So, you need to block some of this off.
>>    With the hose in the airbox's hole (kinky), I marked and then
>> punched two holes in the hose. Small holes. One hole went into the
>> hose right where the hole for the elbow tube's srew used to be. The
>> other hole went just below there on the hose, the two holes barely
>> half an inch apart. I then used a baggie tie to hold the hose tight
>> to the airbox by feeding it through the two holes in the hose and
>> the hole where the elbow tube's screw once was. I hope that that
>> makes sense - poorly worded.
>>    Anyhow, this leaves gaps, which, my being from Maine, I sealed
>> off with duct tape. You're not a true Mainiac unless you have duct
>> tape somewhere on your car.
>>    I put the airbox's doughnut rings back on, holding it in place,
>> then put the top half back on, and reaffixed all the hoses and such.
>>    I moved to the bottom of the hose and trimmed this, as well, so
>> that there was barely more than 2" of hose protruding out the hole
>> in the front spoiler.
>>    Then I cut out a square of the screen about 5" on a side.
>>    I wrapped this gently about the end of the extra length of hosing
>> that I had, to approximate a good fit, wrapping the corners around
>> the hose and such. I used scissors to trim the corners and the rest
>> of the excess off so that it only ran about 3" up the length of the
>> hose. It's something like wrapping a present.
>>    I slid the hose out from the screen, holding it in its shape but
>> never actually FOLDING the screen. Folding it would, later on, most
>> likely cause it to snap, as thin, metal wires like to do. The whole
>> thing was kind of malleable in my hand, but I managed to get it to
>> keep it shape.
>>    I then slid this cap-like shape over the tip of the bottom end of
>> the hose sticking out through the spoiler's hole. I fitted one of
>> the metal clamps around this whole thing, then began to tighten the
>> screw with my fingers, holding the whole thing together with the
>> other hand.
>>    When the clamp held the screen well enough to the hose, about an
>> inch or so up it, I got the screwdriver and tightened it more, so
>> that the clamp barely squeezed the hose in - a tiny indentation
>> could be seen from the inside of the hose. Tight enough, I figured.
>>    I pushed the whole thing into the car a bit, back through the
>> hole, so that barely an inch remained outside, and the clamp was
>> basically in line with the hole - not forwards nor rearwards of
>> it.
>>    I checked to make sure that my pushing the hose back into the
>> hole had not caused it to slip and come into contact with the fan
>> or the driving belt. It hadn't, since it's wedged in there pretty
>> tightly.
>>    That's about it. Everything is nice and tight. The car revs
>> freely, and gets fresher air at higher speeds - perhaps even slightly
>> compressed air from that sort of ram. The car's temperature stays
>> nice and low - I still haven't seen 230oF as an oil temp for over a
>> month (and I don't have an oil cooler or anything of that sort). My
>> air filter is a K+N drop-in - no big deal.
>>    What I'd LOVE to have been able to do is have a notch cut into
>> my hood and a kind of plastic or carbon-fibre boot fit there to
>> kind of plug into a sort of shute which would feed directly into
>> the airbox, as a number of recent Subarus have, albeit on the
>> passenger's side and not in the centre. Like I said, though, I'm
>> a clutz when it comes to constructing such things and having them
>> work, let alone look good, and I thought it best not to cut up my
>> hood in light of this fact. Oh, well.
>>    All in all, it works. It's low-profile, though it doesn't
>> necessarily look great, what with the duct tape and all. It's safely
>> wedged into place. No big deal.
>>    Now ...
>>    If any of you knows of a similar sort of air intake modification
>> kit that's available, please let me know. I'd love to have a more
>> professional-looking setup for my car. Or, if any of you is skilled
>> with constructing such a thing, why not give it a shot? I'd certainly
>> buy such a kit!
>>    Anyhow, pardon my long-windedness. Hope it wasn't too dull.
>> -Tom
>> 
>>           /=-                -=\----/=-                -=\
>>          /|     -=Thomas J. Boyer<cyng@lamere.net>=-     |\
>> O>///////|O>====================----====================<|O\\\\\\\<O
>>          \|      -=Tsaim Kurros<pen.mip.net 4000>=-      |/
>>           \=-                 -=woot=-                 -=/
>> .     .     .  q u e   h a y   s i n   m i   a m o r ? .     .     .
>> 
>> 
>