Your idea sounds great, except for the first time it rains...

Now if you could put in a flapper valve with a rubber gasket, or a sliding gate on the underside of the hood to seal it off in case of rain, you might have something. You could install an actuator cable under the dash, so if you hit a shower, just pull the lever.

The HSU would be to rig it with a solenoid and a moisture sensing switch that would handle the task automatically - cause you know, you might forget one time and then....

 

it wouldn't be as big of a deal as you think that it would... as long as you were not underwater, you could just shield the top (plumb) of the filter so that the rain wouldn't drop on it... it would just fall into the filter box and run out the bottom.

 

So, I guess K&N and AEM are out!

 

because taking it off has less restrictions... a lot of the problem is the big ass bong under the car that the air has to travel through before getting up and into the engine... the intake was designed to be quiet, not the best performing... if it was designed with performance in mind, they wouldn't have come out with a GM intake, would they?

 

I've been doing some more looking and it looks like I will build a thin, wide duct on the bottom of the hood to move air from a scoop in the middle of the hood to the air box seal. This is because the air box strattles the ridge on the hood, making placing a scoop directly over it impractical. Anyway, with the duct (which, BTW, is an old school GM approach) there would be room to place a flapper (again, another old school solution, but then they were vacuum operated).

The nice thing about the design is that the stock inlet would be the back-up - sealing the cold air inlet wouldn't starve the engine (any more than it is without the hood intake).

 

i'd suggest that you add a drain hole someplace on your duct. ideally where it would not drip on anything important. a 1/4 or maybe 3/8 hole should do nicely.

 

The only way this would work is to put a ball valve at the lowest point of the air box. When water would enter, it would float the valve and run out. This would allow the airbox to be pressurized by the ram-air effect of the hood scoop - assuming you want the ram air effect and not just a source of cold air.

The ram air effect is difficult to achieve because the engine is trying to use almost 300cfm at WOT, max rpm while the scoop is trying to feed it. About 1 lb "boost" or positive manifold pressure will theoretically yield a 5% hp increase. To achieve this amount of manifold pressure typically takes a vehicle speed of well over 120mph, even with an "indy" size hood scoop.

The moral of the story: On a Cobalt, the ram-air effect would be totally useless in 1/4 mile drag. It would make some usable HP if you were trying for a top speed run though. For normal street applications, the cold air effect (increase in density) will be of much greater importance than the ram-air increase in density.

 

I fully agree. It's an "old school" habit to call it "Ram Air." That was advertising hype (still is - a couple years ago Pontiac said the Grand Am GT had "ram air," which was hard to believe because the air box was open to the fender, negating any pressurization effect, much like the GMPP will be on the Cobalt).

Speaking of ram air, there's a reason the scoops on Pro Stock cars are so tall. You have to get that high to get out of the boundry layer of the hood and actually get good positive flow at speed. For the street, I prefer a much lower scoop.

I'll settle for a nice scoop (more for looks-ego than anything else) and outside air ducted from the scoop to the GMPP intake. I believe it will also quiet the intake honk at full throttle a bit, also (but that may be whishfull thinking).

We plan to get the intake ordered today. Will keep the board informed (with pics) as this evolves.

Dennis, if the duct design works out, I'll pass the template along to you for your installation if you want to do some fabricating.

-J-

 

whats the cheapest place that has this intake online? i just cant seem to find it.

 

I believe GMpartsdirect.com has it at a decent (though stillIMO overpriced) price

 

gmpartsdirect.com $293.38

Go to their main page, put the following number in the search field just under their logo:

17800653

 

isnt there anywhere that has it for like 250ish?

 

Right - on a pro stock car they want the bottom opening of the scoop to be a bit off the hood, since the air right on top of the hood is turbulent. They also generally want the middle of the opening to be on a line drawn between the top of the frontal area (ie top of the nose) to the front of the roof.

Too high/too big of a scoop causes too much drag and slows the car down, while too small of a scoop doesn't allow enough air in and hurts power that way. Pro stock guys, especially guys like WJ and Greg Anderson; do a lot of wind tunnel testing to optimize their hood scoops and bodies in general.

 

$261 and it's not even a cold air intake..you can find a CIA online for $160 or even an injen wich is my best,.. was $230 and is a CIA. i've seen them before online and honestly it's the same thing as that "make it your self" intake system you can buy at pep biys where you buy each peice seperatly

-drew

 

It IS a cold air intake, and yes it is overpriced. I would say it is a higher quality piece than a do it yourself. It fits like it should and dosen't rub anywhere like I here some of the other kits do, so maybe you get what you pay for.
Dennis

 

it's a WAI .. it is still under the hood and in the engin bay it just sits in the stock airbox without the top on it..mine dosnt rub if you install it correctly

-drew

 

It's a cold air intake. The box is sealed by the hood when it is closed. Air comes in from the fenderwell fust like yours. If the intake being mounted under the hood makes it wai, yours is too since it has to go through the engine compartment to get to the throttle body.
Dennis

 

Correct me if I'm wrong. This is 300 bucks for an air filter and a plastic box ?

 

Well, it also has a nice shiny intake tube

It's my opinion that the open top and seal aren't designed to seal to the under side of the stock hood, but to a duct mounted to the bottom of the hood that ducts air from a scoop to the airbox inlet. This has been typical GM practice for cold air induction since the '60's. I wouldn't be surprised if there isn't a matching hood in the works.

I ordered one of these yesterday and I will be fabricating my own duct to bring in air from a center mounted scoop to the top of the air box. That ends the CAI controversy - it would then definitely be a CAI system. The stock inlet would then be a "back-up." The so-called Ram Air on the Grand Am a couple years ago was similar, except the duct was fixed to the top of the engine instead of to the hood.

Note that we were told that these are temporarily out of stock, but that a new batch is expected within 1-2 weeks. There was also some indication that these will not be produced after a couple of months, so they may be a moot point soon. Hopefully I will get one before GM cancels them. GM has a long history of this with their performance parts - very low production, no anouncement of availability or cataloging of items. If you are "in" with GMPP, you know. If not, they're here and gone before you know about it.

 

Dead cost is like $240, so you won't find it much cheaper than $250-260.

 

id take it for 260 if i could find it that cheap

 

This intakes cost is $227.54, MY cost as a GM parts department employee is 10% over the dealers cost and that puts it at $250.25 + tax. I can't imagine you finding it much cheaper then this. But if you can let us in on where your getting it from!

 

Lewiss: Well, it also has a nice shiny intake tube.


That sounds better. I didn't see a picture or description on the GM web site.

 

http://www.gmpartsdirect.com/results...umber=17800653

DESCRIPTION: Air intake

Performance Air Intake Kit

This kit is NOT for SS and SS supercharged Cobalts.

thats what it says on the site. i was really considering this intake too. do they have one specifically for the SS 2.4?

 

I'll post how it works on my 2.4 SS, since I already have on in transit. Mine will be a through-the-hood outside air intake, as I plan to cut a hole in the hood above the air box and put a scoop over it. This won't be ram air since I don't want to put a scoop on it that's tall enough to get out of the boundry layer, but it will still be cold air intake since it seals against the bottom of the hood and will be breathing through the hood.

If it throws codes, I will NOT be a happy camper!

If the intake and my scoop (both in transit) come in before the weekend, I will be busy butchering a perfectly good SS hood and installing a part that is specifically prohibited for my car Maybe I'll try just the intake first BEFORE cutting the hole!