Custom CAI(at last)

[RTsang]

Originally Posted by ChinoCharles

Cooler air is more dense than warm air because on a microscopic level there is less mollecular movement of the air itself. In other words, you can cram more cold air than warm air into the same space.

The first two strokes of an internal combustion engine have to do with first taking air and fuel into the combustion chamber, then compressing this mixture right before ignition. A cold air intake does a few things to help this process along. First, it (usually) relocates your source of air further from heat-producing parts of the engine, hence the term cold air intake. Second, it (usually) cuts down the length of space in which the air has to move, thus your air hits the intake manifold at a higher speed. Both of these facts mean more air in the combustion chamber, and more air means more oxygen which means a more violent ignition... which means more HP!

How does this affect the mileage? I can't imagine getting extra HP without decreasing the MPG.

[Katana]

Εxcellent explanation!It couldn't be better!

[jeff_o]

wow... chinocharles.. everything you said makes sense... now i understand... it's all physics. by the way have you heard of the vortex air intake? it just swirls the air going towards your intake manifold... i kinda don't believe it will give you more HP as opposed to what they advertise. whatcha think man?

[paultyler_82]

Originally Posted by jeff_o

wow... chinocharles.. everything you said makes sense... now i understand... it's all physics. by the way have you heard of the vortex air intake? it just swirls the air going towards your intake manifold... i kinda don't believe it will give you more HP as opposed to what they advertise. whatcha think man?

Those "Tornado Fuel Savers" or the other 50 names they go by are complete and total BS, they actually end up making the intake a little more restrictive! Other scams to watch out for are the fuel line magnets and the "electric superchargers"

[ChinoCharles]

I've heard some real-world gains with Tornado's and related products, but it could be bullshit. I've never had one myself so I can't really vouch for it. IMHO if you're one of the people looking to stretch the gas mileage on your Yaris (I'm not that person) go drop the 15 bucks or so on a vortex generator and test it out. What do you have to lose?

As far as how it affects mileage, I don't know much about cars but I do know my math and science (physics) and I'll propose this idea and someone smarter can correct me if I am wrong, but... in the intake there is a sensor for the amount and composition (temp, speed, etc) of air coming into the engine, and according to this reading fuel is richened or... uhm... stoicized? (thinned out haha) Like I said, CAI means more oxygen which means the engine (with the MAF sensor info) will "know" it doesn't need as much fuel and will use less accordingly. I don't know a wrench from a mouse, but it makes sense to me.

[johnnyfive]

Originally Posted by ChinoCharles

CAI means more oxygen which means the engine (with the MAF sensor info) will "know" it doesn't need as much fuel and will use less accordingly. I don't know a wrench from a mouse, but it makes sense to me.

the more oxygen/air the MAF senser sees the more fuel the computer would send to the engine to maintain the proper ratio.

but at a similar air flow the engine will see the same amount of fuel with or without a cold air system.

but the colder the air, which the temp sensor should pick up, also adding more fuel to compensate for the denser/coler air?

it would seem to me that with either better flow or with cooler intake temps the engine would see more fuel at a given throtle position?

so you will either get a gain in power at that throtle position, or you will need less throtle to net the same power from the engine.

i am no scientist or expert (or english major) but that is just the way i see it, i may be wrong, but just maybe something to think about.



edit: i thought i was posibly clarifying something, but after posting, i am not sure if my original intent was reached...sorry if i confuse anyone

[obylium]

Originally Posted by ChinoCharles

I've heard some real-world gains with Tornado's and related products, but it could be bullshit. I've never had one myself so I can't really vouch for it. IMHO if you're one of the people looking to stretch the gas mileage on your Yaris (I'm not that person) go drop the 15 bucks or so on a vortex generator and test it out. What do you have to lose?

As far as how it affects mileage, I don't know much about cars but I do know my math and science (physics) and I'll propose this idea and someone smarter can correct me if I am wrong, but... in the intake there is a sensor for the amount and composition (temp, speed, etc) of air coming into the engine, and according to this reading fuel is richened or... uhm... stoicized? (thinned out haha) Like I said, CAI means more oxygen which means the engine (with the MAF sensor info) will "know" it doesn't need as much fuel and will use less accordingly. I don't know a wrench from a mouse, but it makes sense to me.

I actually have one of these vortex generators on order and it should come in within a few weeks. I can let you all know if there is improvement, if any on my new CAI.

[eTiMaGo]

Originally Posted by obylium

I actually have one of these vortex generators on order and it should come in within a few weeks. I can let you all know if there is improvement, if any on my new CAI.

LOL don't expect any improvement, but more likely a decrease in performance... those things are the scam of the century, Popular Mechanics even did some in-depth tests on a variety of such cheap "performance-improving" devices and found them to be absolutely useless.

Just think about it, after going through your filter and any bends in the air intake, isn't the air flow already spinning around in all directions? Why add a device to add turbulence when it's already there? All it's gonna do is create a restriction to the air flowing in... And, since they're so simple and cheap to make, and make such improvements to power and fuel consumption, why wouldn't the manufacturers have them pre-installed?

Just think about that

[Katana]

Yes exactly.I have to say that the consumption of fuel isn't affected at all.If you drive carefully, the car remains as economic as before.

[IsLNdbOi]

So bottom line is that if you drive the same way after installing a CAI, your MPG will go down?

[Katana]

I don't know if it will go down, but for sure it will not go up.

[Katana]

Ιn order to be sure about, I just measured my fuel consumption and it was pretty much the same.

I am telling you guys, the only difference you will see, will only take place if you stop driving economically, because of the perfect sound tha CAI makes.

[ChinoCharles]

Originally Posted by johnnyfive

the more oxygen/air the MAF senser sees the more fuel the computer would send to the engine to maintain the proper ratio.

but at a similar air flow the engine will see the same amount of fuel with or without a cold air system.

but the colder the air, which the temp sensor should pick up, also adding more fuel to compensate for the denser/coler air?

it would seem to me that with either better flow or with cooler intake temps the engine would see more fuel at a given throtle position?

so you will either get a gain in power at that throtle position, or you will need less throtle to net the same power from the engine.

i am no scientist or expert (or english major) but that is just the way i see it, i may be wrong, but just maybe something to think about.



edit: i thought i was posibly clarifying something, but after posting, i am not sure if my original intent was reached...sorry if i confuse anyone

The more oxygen present in the cylinder, the less fuel it would take to start an ignition... since oxygen feeds fires by default a spark applied to a smaller amount of fuel with more oxygen in the cylinder should result in a strong enough ignition to complete the cycle. The MAF sensor would mitigate this and the result would be improved mileage.

Know that most people will tell you a CAI is SUPPOSED to improve mileage. The difference may be negligable on a 1.5 L 4 banger, but as your engine gets larger the difference should become more noticable.

[regulus]

Originally Posted by ChinoCharles

The more oxygen present in the cylinder, the less fuel it would take to start an ignition... since oxygen feeds fires by default a spark applied to a smaller amount of fuel with more oxygen in the cylinder should result in a strong enough ignition to complete the cycle. The MAF sensor would mitigate this and the result would be improved mileage.

Know that most people will tell you a CAI is SUPPOSED to improve mileage. The difference may be negligable on a 1.5 L 4 banger, but as your engine gets larger the difference should become more noticable.

If the computer managing the engine is set to keep the gas/oxygen ratio the same the CAI means more gas in the chamber.

Ignition might be easier with more oxygen but im not sure the computer is concerned with that when the engine is warm.

Last, expansion is due to the increased volume of compounds in the air phase in the chamber (CO2 and H2O) after ignition and the increased temperature.

In physics you cannot gain anything from nothing. You loose somewhere and this is on gas efficiency

[Katana]

Well said mate.

I have to say that in case anyone needs to make a CAI I am here to provide him with any useful information on it, like measurements, AFM(MAF) install etc.

[ChinoCharles]

I don't know... the TRD option in America looks nice because it has that built in valve to stop water intake, which frees you up to place the cone where you will see the biggest gains. You don't see that on the AEM intake that was just released, and the TRD is only 30 or 40 bucks more if you order it from trdsparks... some food for thought.

[Katana]

Yeah right.

But I think that the place, from where the TRD CAI takes on fresh air is not the best choice.

How much does it cost?

I paid 170 euros for the custom CAI.

[ChinoCharles]

Thats about 215 bucks... more than a hundred dollars cheaper than the TRD option here, but we all know that money spends a lot different depending on where you are. Who knows what the hell any of this means, haha.

I'm not crazy about where the cone on the TRD option sits either, but I've got some plans to free up some air... possibly cut a hole in the front bumper and throw a gromit and some mesh in there. Functional ram air sans lame-ass hood scoop.