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Engine Specific Info and Questions => IDI Engine => Topic started by: overdrivegear on September 01, 2010, 12:15:49 pm

Title: New cold air intake design
Post by: overdrivegear on September 01, 2010, 12:15:49 pm
(http://lh5.ggpht.com/_l6Ce480D_oM/TH5Zeh9EN3I/AAAAAAAAAOc/3nsfYlaLk8M/s800/IMG_20100827_225316.jpg)

(http://lh4.ggpht.com/_l6Ce480D_oM/TH5Z5T1UFVI/AAAAAAAAAOg/xyPnKHOKE0s/s800/IMG_20100827_225712.jpg)

(http://lh4.ggpht.com/_l6Ce480D_oM/TH5awWf882I/AAAAAAAAAOk/QBMyjOWEWm8/s800/IMG_20100827_231325.jpg)

New cold air intake for my cabriolet diesel.  Made with a special rubber flex hose with smooth inner and vacuum attachment at the bottom.  Makes the car run very smoothly at 60 mph with much less emission when I hit the throttle.  Definitely delivers a cold air charge and perhaps helps out a bit with volumetric efficiency, fresh air scavenging, etc.  Obviously there really isn't any serious performance gain, but it seems to run cleaner this way. 

Clearly if I drive through a pond of water 18" deep, I'm screwed but then again, I don't plan on doing any jungle cruising.  The attachment brackets are medium gauge sheet metal so if I forget it's there and pull up too close to a parking barrier, it will simply flex the brackets back and not bend my valance.   
Title: Re: New cold air intake design
Post by: GEE-BEE on September 01, 2010, 12:23:43 pm
I wondered what happened to my vacuum nozzle ?

here are some other idea's

aircraftspruce.com

cat duct 2' :05-29808
flange 2'     10350-8
other sizes available

Drill a hole, pop rivet the flange, connect to intake inlet
You can also add another flange and connect to a hole in a airbox assy
This is what Iam installing, this would be a std type of install on aircraft
Gee-Bee
Title: Re: New cold air intake design
Post by: Vincent Waldon on September 01, 2010, 12:43:19 pm
Very clean install!!!  My 81 caddy always felt a bit quicker on the highway with my shop-vac intake... nowhere near as well done as yours tho.

Since this is the internet... someone's gotta state the obvious caution: at 23:1 compression the combustion chamber volume of a 1.6l diesel is 16.7cc or a little over 1.2 tablespoons.  Deep puddles aside, any more rain or splashing than that in a single gulp and a rod is going to get bent.  Obviously it's gotta get past the air filter etc and be ingested all in one swallow... but 1.2 tablespoons is not a lot of water, either.

1.2 tablespoons... just something to be aware of on cloudy days!
Title: Re: New cold air intake design
Post by: GEE-BEE on September 01, 2010, 12:57:48 pm
I think a 2' hole and flange next to the headlight would be cleaner and safer, air would be a direct shot also
cat tubing  can be purchased in any size along with the flanges.

GB
Title: Re: New cold air intake design
Post by: Vangruver on September 01, 2010, 02:31:27 pm
(http://www.autosportz.com/air_intakes/aem_bypass_valve_example.jpg)

i like that idea! but might I suggest that you install a bypass valve such as the one shown above?

while the CAI is a great upgrade for almost every car, it still has a potential to take in moisture whilst driving. The bypass valve will trap all moisture into the lower portion letting it drain prior to the air going into the intake.
Title: Re: New cold air intake design
Post by: madmedix on September 01, 2010, 03:19:48 pm
After looking at the bypass valve on their website: it occured to me that maybe using a section of rubber intake, cut in half, then a section of open-cell foam rubber-cemented to it would work well (the kind of foam sheet that electronics is packed in)...or...how about using some wrapped around the intake at a bend at the lowest point and secured with dryer clamps on both ends..there would be some air loss but water sucked in that scoop would blow out the foam curve instead of climbing up the intake?

Title: Re: New cold air intake design
Post by: vanbcguy on September 01, 2010, 08:20:45 pm
Very clean install!!!  My 81 caddy always felt a bit quicker on the highway with my shop-vac intake... nowhere near as well done as yours tho.

Since this is the internet... someone's gotta state the obvious caution: at 23:1 compression the combustion chamber volume of a 1.6l diesel is 16.7cc or a little over 1.2 tablespoons.  Deep puddles aside, any more rain or splashing than that in a single gulp and a rod is going to get bent.  Obviously it's gotta get past the air filter etc and be ingested all in one swallow... but 1.2 tablespoons is not a lot of water, either.

1.2 tablespoons... just something to be aware of on cloudy days!

At 2400 RPM though that's 24 tablespoons per second... Immerse that sucker and yeah, you have problems but in reality it'd take quite a bit of water to actually get that much flowing all the way up the intake.  DEFINITELY not something for a car driving on gravel roads with lots of deep puddles though!
Title: Re: New cold air intake design
Post by: gldgti on September 02, 2010, 09:04:53 am
air filter makes a good misting device.

I have had a 3.5" PVC intake on my n/a diesels for a long time. I did once plumb it down to the area shown by the OP but found on hot australian summer days it did more harm than good, with superheated air from the road coming in.

i have found the best compromise to be just behind the grill next to the radiator, and as an added bonus it makes it fun when changing the air filter to count the insects :-)
Title: Re: New cold air intake design
Post by: Dirtrag2 on September 03, 2010, 07:30:41 pm

At 2400 RPM though that's 24 tablespoons per second... Immerse that sucker and yeah, you have problems but in reality it'd take quite a bit of water to actually get that much flowing all the way up the intake.  DEFINITELY not something for a car driving on gravel roads with lots of deep puddles though!

can't be much worse than running water/meth injection... hmmm I wonder... anyone ever figure out a safe water injection flow rate on idi's  ???
Title: Re: New cold air intake design
Post by: UAofE on September 05, 2010, 10:21:43 am
Thats a very nice water scoop.
Title: Re: New cold air intake design
Post by: theman53 on September 05, 2010, 11:38:41 am
I had mine on the passenger side. I think yours will be fine as it seems where I am from most of the big holes are on the passenger side. Plus you have to over come gravity to get it all the way up there and water is a lot heavier than air. Unless it is a fine mist of water and then it shouldn't hurt you :D
Title: Re: New cold air intake design
Post by: R.O.R-2.0 on September 05, 2010, 11:45:16 am
i would have gone with ALOT BIGGER tubing from the front to the air box. think of how bad the stock snorkel flows? well now take and make it 4 times as long.. yea... its gonna really have sub-standard flow. is the gain from the cool air enough to counter-act the tiny intake tubing? and ive also heard it causes excess turbulence using that hose with a spring in the core.. kinda like using dryer hose for an intake.

and you could have taken and mounted your vacuum cleaner behind one of the little mini-grilles under the bumper.. then it would have been totally hidden  ;)
Title: Re: New cold air intake design
Post by: GEE-BEE on September 05, 2010, 06:02:12 pm
On that note : I would use a 1Y intake and go from there

GB
Title: Re: New cold air intake design
Post by: R.O.R-2.0 on September 06, 2010, 12:48:31 pm
not everyone can afford expensive intake manifolds.
and on a 1.6, a gasser intake would be better, because it actually has the right intake ports. and gasser manifolds are WAY cheaper, and work just as good.
Title: Re: New cold air intake design
Post by: GEE-BEE on September 06, 2010, 02:52:58 pm
I have a 1Y sitting and the stock snorkel tube in a box for 150.00

I did have it professionally cleaned

I havent seen a 1Y filter assy thou..

GB
Title: Re: New cold air intake design
Post by: R.O.R-2.0 on September 06, 2010, 03:06:27 pm
1Y manifolds are only good for TDI/AAZ heads tho. D port manifolds on 0 port heads do not flow well at all..
Title: Re: New cold air intake design
Post by: UAofE on September 27, 2010, 03:37:44 am
i would have gone with ALOT BIGGER tubing from the front to the air box.

Lower air velocity also means less energy to push water into the intake.
Title: Re: New cold air intake design
Post by: stewardc on September 28, 2010, 04:48:52 am
This is factory CAI
(http://img.photobucket.com/albums/v648/stewardc/Truck/100_4164.jpg)
Title: Re: New cold air intake design
Post by: theman53 on September 28, 2010, 08:36:55 am
That is neat. I think the raintray from the GTI is going to become that factory CAI on my car :D
Title: Re: New cold air intake design
Post by: ktzdsl on September 28, 2010, 08:25:55 pm
stewardc:
What is the year/model of your picture with the factory CAI?
Title: Re: New cold air intake design
Post by: stewardc on September 28, 2010, 08:46:23 pm
stewardc:
What is the year/model of your picture with the factory CAI?

It's on my 1981 Caddy. I suspect this part is from a Jetta of the same vintage.
Title: Re: New cold air intake design
Post by: ktzdsl on September 29, 2010, 08:51:59 pm
My research shows 82-84 for Jetta implementation like you have; 85 up had a piece that fit a hole in the side of the fender and then to the air cleaner. The same design that you have was used by after market and the cost increased accordingly. Thanks.