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Old 10-27-2000, 09:34 AM   #1
zaphod
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Join Date: Oct 1999
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Blue Ridge Pearl

Question Hood-scoop intake and water?

Hi Everyone,

I've given up hope on the supercharger for now. So instead of doing nothing at all, I'd like to construct a forced-induction through the hood-scope. Yeah, I know it won't be much unless I'm over 300 or 400 MPH (haha), but I have a question about water interfering with the engine's proper operations.

I've read the recent post someone had about water into the engine via the leaking air filter. This question concerns a bit more water entering the engine...

When I modify the hood-scoop to become the air-intake, should I worry about disconnecting the plumbing when it rains? If not drizzle, what about heavy/torential rains?

Obviously with the hood-scoop, more water will enter the engine than would under normal conditions from water vapor off the road during rain storms.

Can anyone provide some more detailed info about this? How much water is too much? How will this affect other aspects of engine performance including timing, compression, etc.?

Thanks in advance and cheers from København, Denmark (for now).
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Old 10-27-2000, 01:07 PM   #2
STiShawn
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You could design an intake box that would "catch" the big amounts of water and drain it off. Uf your running a K&N filter, they are semi water impervious. Keep it WELL oiled and clean. hope this helps, I have a 99 so Im S.O.L.
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Old 10-27-2000, 01:16 PM   #3
10th Warrior
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i have my vents and scoop opened with the silencer removed (MY00). granted, everything is stock but i have had no problem with water, even in torrential downpours. i did get some mud on the intake box cover, but that's another story.

just my $.02
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Old 10-27-2000, 01:17 PM   #4
uktena
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Exclamation

Ask brucelee, he had picutes posted of the induction system he built for his car. It looked as if he had done a good job.
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Old 10-27-2000, 03:42 PM   #5
DEVO
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00

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I actually opened up my half-box (taped up the intake pipe), opened a big section of it.. just cut it off.

Mine doesn't (and shouldn't) have any problems regarding water..
If you take the half-box(one not connected to throttle body) and look at it carefully, you'll actually see a little hole under it.. and since the filter sits straight up, any water build up would just drain away. And I do have a K&N just for overall well being

Also, the part right beneath the scoop is the part that connects to the throttle body, so water falls on there and the ridges on the box would trap most them.

although it probably wouldn't be as effective as 8complex's, but it's weather proof, except you might wanna open it to clean larger particles or leaves once in a while.

hope it helps
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Old 02-06-2001, 11:34 AM   #6
Jonnathan
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Supercharger ?? tell me more ?
do you have a kit ? is it the Rimmer engineering kit ?
does anyone know anyone who has a supercharger on their RS ?
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Old 02-06-2001, 01:15 PM   #7
Wreckleford
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You guys seem to be forgetting that when engine is running your intake box is under negative pressure, due to the sucking of your engine. So when water goes in, more than likely it will get pulled through the filter and into the engine, rather than collecting at the bottom and flowing through the hole. Also the oil on the K&N filter won't do **** to stop water from coming through.

Having said that, it is not necessarily dangerous to have one of these intakes. When it rains, although you will be pulling in water, you are not likely to pull in enough to hydrolock your engine. You only have to worry about a lot of water splashing right onto your filter from a puddle or something.
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Old 02-06-2001, 01:34 PM   #8
zaphod
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Wow, I never thought I'd see this thread come back to life... ;o)

So wreckleford, what you're saying is that I wouldn't necessarily have problems with the water coming into the engine? Other than perhaps stalling or rough idling, how would I know when I'm in a hyrdrolocked state?

Here's a thought: in the boating world, to combat condensation in the gasoline tank (and any accidental water) it's recommended to put some isopropyl alcohol in with the gasoline. The reasoning is that alcohols will bond with water and pull through the engine (and out the exhaust, ridding the entire system of the water).

Can I assume that our engines would work in the same matter since virtually all fuels today have up to 10% ethanol (an alcohol derived from corn) content??
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Old 02-06-2001, 04:37 PM   #9
Reciprocity
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Thumbs up

I feel that I have created a rather elegant solution to the problem of a cowl-induction set up...as well as solved the problem of massive amounts of water pouring over a filter.

First of all...I will post some pictures of the custom fiberglass intake my friend and I made....

<IMG SRC="http://216.242.153.40/MembersList/UserPics/1126/intake01.jpg" border=0>


<IMG SRC="http://216.242.153.40/MembersList/UserPics/1126/intake02.jpg" border=0>


<IMG SRC="http://216.242.153.40/MembersList/UserPics/1126/intake04.jpg" border=0>

Here is a link to the original thread... http://www.i-club.com/ubb-files/Foru...ML/001042.html

Anyway...we have now taken it a couple steps further. At home I have a new and better designed cold air box drying out...it fits the car much better and the shape is smoother and more refined. The orignal box I have made is in my car...painted...and weather stripped to give it a good tight finish.

I was concerned about water running directly onto the filter to I cut a small piece of metal to fit onto the original mounting points for the scoop plate, right in the middle...and cut the piece as well as bent the sides down to serve as a cover for the filter itself when the hood is closed. One thing I did not plan on...is a gain of low end torque from the cover! I suppose it creates more of a plenum effect in the box...butt dyno loves it for sure. The pickup was noticable enough for me to post it here!

Anyway...within the next couple days I should be posting more info and more pictures of the setup.

If anyone has any questions, feel free to ask!

Yes...I will be selling some...once I am sure they are as perfect as can be...both in looks, fit, and performance.

D. Neil Crawford
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Old 02-06-2001, 07:18 PM   #10
meebs
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keep in mind the hood scoop is pretty much non functional after probably 70+mph due to the aero of the car. The faster you go, the bigger "wall" of air you push in front of the car.

And at speeds slower than 70, you aren't forcing much air into the box. But it would definatly suck fresh air if you put the intake there and seal it to the scoop.
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Old 02-06-2001, 11:49 PM   #11
FLUBYUx2
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Meebs, so what youre saying is that the old Stingrays w/ the stinger hood scoops, the New and old ram air Firebirds, and the camaro SS's and Z28s have non functional hood scoops after 70+mph??? lol
thats a good one!

the scooby has a tall enuf hood scoop, that it will have air Crammed into it at speeds 45+mph. as for speeds Less than 45-mph. i think that the air isnt flowing fast enuf to Pressureize the airbox enuf to create Ram-air. so, its basically only Cold air induction at that point. the Same idea behind Cobb and ganzflows intake designs.

this cold air/ram air set up using the intake scoop is the BEST idea, in the old Hot rodding sense of 'Work with what ya got'. thats what makes hot rodding special. it USED to be about making your own parts and mods. not just BUYING bolt ons. fabricating, and making the best use of what the factory supplies you with is the HEART of hot rodding, whether its in the USDM or the JDM.

thats what bugs me about Rice boys w/ theire Altezza taillights, one wiper, windshield banner, bookshelf wing, civics and preludes...buncha posers. if hot rodding was so easy, everyone would do it. but it looks like lots of people are lazy, and dont have as much enthusiasm about Making their own parts, so they take the easy way out, and have NOPI parts on their speed dial.

i saw a hacked together PVC intake elsewhere on this bb, 'powered by Home Depot'. that guy gets an A for effort. hes got the right idea. so does the creator of this thread, and the like. keep up the Brainstorming people! ...

lol, ok, DONE ranting, hope i didnt step on anyones toes.

"necessity is the mother of invention"
"work with whatcha got"

KUDOS to all who have even TRIED to use theire factory intake scoop and hood vents.

oh no, my brain crapped out on me, i forgot what i was gona say.

chris
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Old 02-07-2001, 12:29 AM   #12
zaphod
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Blue Ridge Pearl

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I spoke with my friendly neighborhood chemistry major and she confirmed what I was thinking about alcohol and water.

According to her all simple alcohols (isopropyl, ethanol, grain, etc.) will create a soluble solution with water. This means that the water and alcohol will form a magnetic attraction so strong that it will only be broken by evaporation of one of the elements.

I also asked what effect the heat of the combustion chamber would have on this process taking into account the extreme pressure. She told me that heat will increase the strength of the attraction and that the compression of the engine would be adequate enough to keep the alcohol from evaporating under the heat.

She felt that as long as you aren't dumping buckets of water into your intake that my idea would work fine. She basically said to just remember that the fuel has a *maximum* of 10% ethanol, and that she doesn't recommend dumping beer or hard liquors into your fuel tank.

Hope this helps everyone! I'll be building my intake hopefully in March when I'm home from the Netherlands for a couple weeks!
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Old 02-07-2001, 06:37 PM   #13
meebs
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Meebs, so what youre saying is that the old Stingrays w/ the stinger hood scoops, the New and old ram air Firebirds, and the camaro SS's and Z28s have non functional hood scoops after 70+mph??? lol
thats a good one!


heh, that isn't what I said at all... but on a Sube it's a different story.
FYI, the WRC car's scoop has been NON functional for about couple years now. The intercooler is on the front of the car, like the EVO.

And sure I agree, work with what you have, but just because you try doesn't mean you are going to skirt around physics.

Making the hoodscoop like that is great for getting colder/fresher air, and I bet it makes the intake sound cool, but you aren't going to generate much pressure.
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Old 02-07-2001, 09:54 PM   #14
CosmoTheCat
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FLUBYUx2

Take a look at the profile of your Scoob. The front is shaped roughly like a loaf of bread. Not exactly the best for carving through the air. Now take a look at the profile on the Vette, Firebird, etc... they're a lot pointier, which tends to split the air better. The Impreza front end will tend to shoot air straight up instead of plying through it. Hence at a certain speed the air will get propelled up far enough to render the scoop useless.
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Old 02-07-2001, 11:36 PM   #15
ImprezaRS dot com
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burninrubber had a sealed-presurized hoodscoop intake and found out he was presurizing the the crankcase (bad) - so you'll want to run your vaccum lines to either a vaccum chamber like some turbo kits, to a catch can, or to their own little filters if you want a true ram-air intake from the scoop...

He finally abandoned it for a cone filter on the end of a tube just off to the side of the open scoop. Works fairly well I'd say from having a ride.

Larry www.ImprezaRS.com
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Old 02-08-2001, 02:08 PM   #16
Reciprocity
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A couple of things...

First of all, I never really thought we could have a "ram air" style intake for the car...to be honest I was looking for a good source of cool air...and the hood scoop seemed just about perfect for it. More than anything else I would call it "cowl induction".

Secondly...and along those lines...it does make sense considering the shape of the front of the car...that air would be traveling over the scoop instead of into it. But what I would like to know...is does anyone know this for a fact, or is it just speculation? And continuing these thoughts...perhaps air is not being forced into that slot...but is it being sucked out? If that is the case...then I do have a big problem!

Going back to the cowl induction vs. ram air thoughts...as long as the scoop can be used as a source of cool, non-engine heated air...then it should work out great...even if it isn't being forced down (besides, the shape of the filter doesn't look like it would be very good for ram air, a flat panel filter and a cold air box shapped to funnel air into the throttle body might work).

Hmmm...about sealing it to the hood. I am using some inch thick foam to close up the gaps, and keep it from banging around. But that is only three sides...the front is open (I was a bit concerned about having too much air forced in, and banging the box around...so I left it open as a sort of escape route).

Finally...the plenum issue. This is something I have thought a lot about, but haven't come to any real conclusions. What I NEED is a G-Tech so I can test it out...see what sort of differences I come across with different size boxes. Putting the car on a dyno wouldn't give me any airflow over the hood (unless I got some really big fans! ) But...it is is only cowl induction, and not ram air then...who knows!

Damn...I think that is about it! 'Nuff said!

D. Neil Crawford
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Old 02-08-2001, 02:49 PM   #17
t.rod
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I'm going to try something like this.
I've been practicing with fiberglass. I've gotten pretty good. So far I've made baffles for the two mids in the front use the stock location. Anyways, My next project is to make this setup. For the crank case I might use little filters.
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Old 02-09-2001, 09:55 AM   #18
adamsrs
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I have a filter directly on the throttle body for a year now. No problem. But I have still just ordered a Cobb Tuning cold air intake. It will make much better performance gains.
adamsrs www.unnatural.org
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Old 02-09-2001, 10:35 AM   #19
fellfrosch7
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I think at a high enough speed, the hood scoop does become non-functional.. Hence the reason why Byron's car has the hood scoop turned 180 degrees, to draw hot air out of the engine bay. Of course, he has a FMIC now, so that's a different story...
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