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View Full Version : Homemade cold air intake



RIVI72
06-28-2008, 08:48 PM
So last weekend my friend got a K&N cold air intake for his mustang and that gave me the idea of making my own so i went to Canadian Tire and got some aluminum dryer hose and cone filter
http://i154.photobucket.com/albums/s278/rivi72/000_0393.jpg
http://i154.photobucket.com/albums/s278/rivi72/000_0392.jpg
http://i154.photobucket.com/albums/s278/rivi72/000_0391.jpg
Not bad for 50 bucks compared to $350 my friend spent i thought it wasnt a bad deal
The car really wakes up at mid range and thru upper range rpm and makes nice little growl and with the cherry bomb turbo lol dont laugh it almost sounds like a grand prix gtp


And the best part driving along on the highway you can actually hear it suck air

CieraSL92
06-28-2008, 10:06 PM
How flammable is the dryer duct?

brp2z
06-28-2008, 10:45 PM
not bad

sure that dryer hose has a lot of drag but the placement is good. i have a couple silverado intake peices im using to make one for the buick
but i had an issue with location

i imagine i could put one where you did

good job

jinxtigr
06-29-2008, 02:34 AM
As somebody else who makes intakes MacGyver-style, I have to say- you should be using a different type of hose, I think.

I'm using air conditioning duct parts that are steel, held together with steel clamps, and there's a duct where you have it, piping air to the filter area, but mine is the more rigid aluminum duct, and even that I'd be wary of between the throttle body and the filter.

My concern is that vibration and suction (and the very high sound pressure levels of the engine intake itself) will vibrate your duct until it breaks. When it does, pieces of duct will get sucked into the engine, along with engine compartment debris if any. Aluminum isn't really harder than steel and it's not like incompressible water so it might survive a duct failure... but for me, I totally would be using something else. I wouldn't use the materials you're using.

You're right though- surface drag isn't that big a deal. Duct area matters, and making airflow go around corners or through bottlenecks matters, but the shape of the duct isn't going to be a big problem.

The Mad Hatter
06-30-2008, 09:02 PM
Jinx, you said you would be concerned with materials between the filter and the TB, would using PVC be bad as well. I've seen some guys with those setups before, and i wondered if it would work. :dunno:

dagr8tim
06-30-2008, 10:44 PM
I've seen more than afew dryer duct intakes. The stuff is ok, but far to thin. What some people use is the rubbed rubber hose that is 2 to 3 inches in diameter. This is often used on landscaping equipment (leaf blowers and sometimes on bagger systems of large drivable mowers). It's also been known to be used as intake hose on larger trucks. Infact I have a 2+ foot section I snagged from a junk yard afew years back that is 3 inches in diameter.

That being said, I have 2 suggestions for your current setup.
#1. Some form of splash shield so that you don't end up hydro locking your motor in a heavy rain.
#2. Adjusting the tubing so that there is a low point between the filter and the intake. In this low spot, cut a small hole to act as a drain, when said water (from suggestion #1) gets into your intake hose.

CieraSL92
06-30-2008, 11:21 PM
My concern is that vibration and suction (and the very high sound pressure levels of the engine intake itself) will vibrate your duct until it breaks. When it does, pieces of duct will get sucked into the engine, along with engine compartment debris if any. Aluminum isn't really harder than steel and it's not like incompressible water so it might survive a duct failure... but for me, I totally would be using something else. I wouldn't use the materials you're using.

You're right though- surface drag isn't that big a deal. Duct area matters, and making airflow go around corners or through bottlenecks matters, but the shape of the duct isn't going to be a big problem.

There should be a metal screen right where the air filter housing to throttle body hose would have connected that would stop *most* particles. You would have seen it if you looked into the TB. People have considered removing it because it could be restrictive-its not, and its the last line of defense.

jinxtigr
07-01-2008, 02:12 PM
Oh yes it is restrictive, and I thought that was what that was for. So, yeah, if you have that there, it would catch any chunks of hose, but better not to have them.

I think you could use PVC. I've also used the heavier dryer duct, the kind that is aluminum that comes compacted and you stretch it out into shape- that stuff should be good.

Now I'm wondering about the possible benefits of a nonrigid air intake- bear in mind there is a suction that is as strong as the resistance of the air filter to air coming in. The thing has to be able to suck a bunch of air through paper (or whatever you use) so there are limits to how weak it can really be without fatiguing and breaking. It's not just a breeze blowing through there.

I need to make my fiberglass air intake... the horn shaped one I thought of...

Also, hydrolocking will happen if the whole intake is underwater. If I understand correctly, as long as air is coming in as well as water, the engine should survive. It's not the presence of water but its incompressibility that causes hydrolocking- if the cylinder has more water in it than the volume of the piston at full compression, it's gonna break. That's a lot of water to take into a cylinder that many times a second into a hot engine... just make sure the air intake isn't underwater. (relevant for things like Minis with the air intakes very low)

RIVI72
07-01-2008, 06:04 PM
So do you guys think i should go to something like this
http://i154.photobucket.com/albums/s278/rivi72/319_1.jpg

Hey dagr8tim what kinda of vehicle did you get your 2 foot section off of

dagr8tim
07-01-2008, 09:36 PM
Hey dagr8tim what kinda of vehicle did you get your 2 foot section off of

That's pretty much it. I'll try to get a pic of the section I got in the next day or two. Sadly the yard I go to doesn't separate trucks & full sized vans by make. I actually found it laying on the ground over in that area. I would look for Ford F & E 150's through 350's, and GM/Dodge from 1500 through 3500.

Maybe even sniff around suppliers for the larger 450's & 4500's that are more commerical type trucks.


Also, hydrolocking will happen if the whole intake is underwater. If I understand correctly, as long as air is coming in as well as water, the engine should survive. It's not the presence of water but its incompressibility that causes hydrolocking- if the cylinder has more water in it than the volume of the piston at full compression, it's gonna break. That's a lot of water to take into a cylinder that many times a second into a hot engine... just make sure the air intake isn't underwater. (relevant for things like Minis with the air intakes very low)

I've seen cars hydrolock on relatively small amounts of water. I have to think in a driving rain storm at highway speeds with the filter directly behind the grill, you could suck enough water through your intake to hurt the car. I know guys that use water injection on classic fords, and they go through 6 - 8 ounces per tank of gas (300 - 400 miles).

Buick_powa
07-01-2008, 11:55 PM
the honeycomb IS really restrictive! I've removed it and feeled a power gain better throttle response and acceleration!

brp2z
07-02-2008, 07:12 AM
i had 2 old o2 sensors and i removed the honey comb from one and all it did was die

LordDurock
07-02-2008, 06:25 PM
if ypu bend some thing to go around the back ofthe cone filter you will get a better ram air set up. (note that what oyu have is not a cold air intake but a ram air set up)

dagr8tim
07-02-2008, 08:12 PM
if ypu bend some thing to go around the back ofthe cone filter you will get a better ram air set up. (note that what oyu have is not a cold air intake but a ram air set up)

Other than using a different hose/pipe, the only other suggestion I have is some kind of shield. That would also keep water from getting directly sucked up in the intake.

I've seen people modify an old coffee can for that, the problem is that they rust too quickly, but something about that shape and size would be perfect as a dust/rain shield.

brp2z
07-02-2008, 08:17 PM
plastic coffee can?
and some paint

dagr8tim
07-02-2008, 10:45 PM
plastic coffee can?
and some paint

As long as the plastic doesn't melt & the can or paint don't give off fumes that hurt the engine.

APC used to make universal cone filter heat shields. They were like $20 at Advance.

Here are some examples:
http://www.osaka-autodesign.com/default.asp?contentID=701
http://www.autotoys.com/x/catalog/RACTIVE_SUPERFLOW_SF007_COLOR_CONE_AIR_FILTER_WITH _HEAT_SHIELD_p_2285.html

This guy came up with a good idea. There *should* be enough room next to the battery to mount a cone there and fab up a 3 sided box to keep radiator air from coming in.

http://www.explorerforum.com/forums/showthread.php?p=1935549

If it were me, I would make the shield out of galvanized steel like is used for duct work. Infact, one of my summer projects is to mount a cone filter on my Cutlass. I'll probably build a similar setup to the guy with the Explorer.

brp2z
07-03-2008, 12:16 AM
there isnt room by the battery
its cramped

Beastlyciera
09-22-2012, 04:37 PM
How do you get the honeycomb out I really want to do that.

turbokinetic
09-24-2012, 02:03 AM
So do you guys think i should go to something like this
http://i154.photobucket.com/albums/s278/rivi72/319_1.jpg

That looks like Duravent hose. This is excellent for intakes. It is high temp and abrasion resistant. I use it on turbo system intakes with good succes. Even after 50,000 miles it is still soft and flexible.