Questions about CAI

[RedStallion43]

Hi, im thinking of getting a CAI considering almost everyone seems to have one. Are there any real gains over a CAI vs. a stock Airbox with a K&N filter and air silencer removed? Also has anyone who switched over to a CAI notice a little difference in there exhaust note? Im considering a fenderwell CAI wich I beleive Mac makes. Any input here would be great.

 

[TripleBlack95]

Yeah, I got one. It looks great, I don't think it really makes that much of a difference - but hell yeah get it for looks. It frees up a little space too.

 

[swingline]

You won't notice a difference but you can hear the sound of air rushing in when you accelerate. They are all the same too so either build your own or get the cheap E-Bay one. I got mine from ProCarParts and it was actually pretty nice.

 

[HISSIN50]

I never had the stock inlet, but the car has a Mac CAI and it looks alright. From pics I have seen, it is smaller than the stock airbox set up, which is nice.

I am not a fan of CAI's though and would have preferred a stock air box. Just weird me.

 

[DFG 5OH]

homeade ones are the best

 

[SeventyMach1]

Better Looks = the only gain IMO. You can hear the air rushing in with a CAI .... but I don't really care for that like some people do.

I got a cheap one off of eBay. Well worth the price. It is the EXACT same thing as the MAC CAI. Just cheaper price.

And my exhaust note didn't change at all.

 

[88GT460]

the idea behind cold air intakes are that the tubes are aluminum or metal instead of the plastic junk. So the metal/aluminum does not get as hot like the plastic does thus making it cooler air, and cooler air is better obviously.

also fender well kits get air from the outside, which is definately cooler than the air inside the engine bay.

 

[RedStallion43]

Thanks guys for all your help. I think im just gonna get a cheapo on ebay, not worth paying 150+ dollars for something that doesnt give u any real gain. Wich ebay CAI are reccomended? Do they have any fenderwell mounted CAI's on ebay? For anybdy who installed a ebay CAI are they a straight swap with our sensors or do things have to be cut and re-wired like i heard about somewhere before? thanks again

 

[Mrgreen94gt]

Are there any real gains over a CAI vs. a stock Airbox with a K&N filter and air silencer removed? Also has anyone who switched over to a CAI notice a little difference in there exhaust note?

Probably not, but it made things feel smoother overall. Exhaust note also smoothed out.

I've had the Mac one on my car for about four years now and it's been fine. Kind of a pain to put back on if you take it off for anything. I'm thinking about getting an 80mm MAF and making my own intake, soon. Had I been more inclined, at the time, I probably would have done that in the first place.

 

[GRGT1994]

the idea behind cold air intakes are that the tubes are aluminum or metal instead of the plastic junk. So the metal/aluminum does not get as hot like the plastic does thus making it cooler air, and cooler air is better obviously.

also fender well kits get air from the outside, which is definately cooler than the air inside the engine bay.

I don't think the first part of what you said is right. High school chemistry taught me that metal conducts heat better than plastic. So the stock plastic piece would actually be a better insulator.

But I think the second thing you said is really what cold air intakes are supposed to do. They pull in cold air from outside of the engine compartment for combustion.

Of course, the stock box is a cold air intake, as it pulls air from the fenderwell. That's why everyone says there is no real performance gain from an aftermarket CAI.

I think the other theoretical gain from an aftermarket CAI is that it has a smooth wall, not all those ridges as the stock unit has. But then there's the point that a certain amount of turbulance in the intake air flow is beneficial. This is the point at which I lose all interest in the subject.

 

[SeventyMach1]

Wich ebay CAI are reccomended? Do they have any fenderwell mounted CAI's on ebay? For anybdy who installed a ebay CAI are they a straight swap with our sensors or do things have to be cut and re-wired like i heard about somewhere before? thanks again

I bought mine from a guy that goes by "mqtautoparts" on eBAy. He ships really fast and has a good feedback. And yes it is a fenderwell mounted CAI. It is a straight swap. You just have to remove your MAF sensor from it's housing. I did however have a tough time mounting it. I had to go to the hardware store & get (2) 4" hose clamps (both for under $1) ..... as 2 of the clamps he sent me were just a hair too small. You may get the same problem ... you may not. I emailed him back and told him about the problem, so he may have fixed that. He offered to send me what I needed, but I told him not to worry about it. No biggie. It sure beats paying $130 - $200 for the like.


FYI.... some people say you have to mount the filter from under the car (behind the plastic area). I DID NOT. I did everything from the top. The surrounding area had everything stock, too. If you just work with it a little, you can get it in there from the top. The other way seems WAY to complicated for this. Work smart, not hard.

 

[illwood]

I don't think the first part of what you said is right. High school chemistry taught me that metal conducts heat better than plastic. So the stock plastic piece would actually be a better insulator.

You're right about heat conduction, but if you remember more of your chemistry class, you'll remember that there is also something called specific heat. Plastic (once hot) will hold the heat longer than metal. This is part why heatsinks are aluminum, not plastic.

I bought mine from X3Racing on Ebay, about $50 shipped. I'm pretty happy with it.

http://cgi.ebay.com/ebaymotors/94-9...cmdZViewItemQQcategoryZ38634QQitemZ7992887943

 

[RedStallion43]

I bought mine from X3Racing on Ebay, about $50 shipped. I'm pretty happy with it.

http://cgi.ebay.com/ebaymotors/94-9...cmdZViewItemQQcategoryZ38634QQitemZ7992887943

Does that one hook into the fenderwell? I also heard problems of going through puddles and the intake sucking it up from the fenderwell. Anyone find truth to this?

 

[deadlast]

Does that one hook into the fenderwell? I also heard problems of going through puddles and the intake sucking it up from the fenderwell. Anyone find truth to this?

unless you have a ram air tube up to the filter, or you removed the plastic splash guard in the tire well, you shouldnt have a problem with water

 

[WHITE94COBRA]

You're right about heat conduction, but if you remember more of your chemistry class, you'll remember that there is also something called specific heat. Plastic (once hot) will hold the heat longer than metal. This is part why heatsinks are aluminum, not plastic.

I bought mine from X3Racing on Ebay, about $50 shipped. I'm pretty happy with it.

http://cgi.ebay.com/ebaymotors/94-9...cmdZViewItemQQcategoryZ38634QQitemZ7992887943

This I'm not so sure about??? If you bring plastic up to melting point (hottest point for plastic) and bring metal up to the same temp, the metal deffinately cools much slower, plastic gets cool and solidifies cool to the touch within minutes. This is also the reason there making composite intake tracts (less heat transfere and lighter, as well as cost i'm sure) You can put your hand on one after a drag run, try that with an aluminum one. I'm deffinately not an expert on the subject, just hands on experience.

Now aluminum holds heat much more than steel.

 

[illwood]

An interesting debate. I'm not a Materials Engineer either (mechanical, yes, materials, no). I would imagine that weight and cost are the two most important benefits that are the reasons for composite intakes these days.

In which case, are you negating the "cold air" aspect by the amount the air heats as it rushes through the tube? How does the boundary layer figure into this for fluid flow? Would the boundary layer be taking most of the heat and how much would it be introducing to the engine? Any guys good at CFD that wanna help?

 

[WHITE94COBRA]

An interesting debate. I'm not a Materials Engineer either (mechanical, yes, materials, no). I would imagine that weight and cost are the two most important benefits that are the reasons for composite intakes these days.

In which case, are you negating the "cold air" aspect by the amount the air heats as it rushes through the tube? How does the boundary layer figure into this for fluid flow? Would the boundary layer be taking most of the heat and how much would it be introducing to the engine? Any guys good at CFD that wanna help?

That was another question I had, composite intake = less heat soak which should equate to cooler air right? So a cai should only make things cooler?? I would be extremely interested in some type of composite intake for our cars, for experimental purposes of course. I would think it would be really expensive to design and make.

 

[18mustangs]

When I put a MAC CAI on several years ago my car felt stronger and accelerated easier. Logic would also tell me that removing all of the 90* bends and the kinked stock air hose and the screen in front of the MAF in the stock air box would all help in the production of power.
Tim

 

[GRGT1994]

You're right about heat conduction, but if you remember more of your chemistry class, you'll remember that there is also something called specific heat. Plastic (once hot) will hold the heat longer than metal. This is part why heatsinks are aluminum, not plastic.

Hmmm. Ya, I think the comment about aluminum heatsinks reinforces what I said. If an aluminum heat sink relieves its heat faster to the outside (cooler) air faster than a plastic heat sink would, then surely a metal CAI would relieve more of its heat to the cool incoming air charge than a plastic one would. So the end result would be, ceteras paribus, hotter air into the engine with a metal intake than a plastic one.

I think my point was simply that the reason for a CAI is not to prevent the intake tube from getting hot (let's face it, whether it's plastic or metal, eventually it will absorb the same amount of heat), but rather the point is to pull intake air from outside of the engine compartment, which is surely cooler than the air under the hood.

But Mustangs come with a CAI to start with, so aftermarket CAI's are purely for looks (and maybe for a smoother intake track).

 

[rgs]

specific heat is the amount of heat needed to raise a 1kg of a certain material 1 degree celsius