intake

[supe]

If after market intakes provide more power and/or make the engine run more efficient, why don't car manufacturers equip their cars with better intakes which cost less then $200.

Is there any cons to getting after market intakes? I guess one would be they are louder which generally is not favorable.

[teggypimp95]

Louder and could run into problems with cold air intake and big puddels. Intake also doesent really add power but more move it on the power band. So now you may have a few more hp at higher rms but maybe a few less with in low rpms. It this way with some cars.

[JRSC00LUDE]

Originally posted by supe
Is there any cons to getting after market intakes? I guess one would be they are louder which generally is not favorable.

You pretty much answered your question right there as too why they don't put them on to begin with.

Also, I personally wouldn't run a CAI on my car in the winter. I've seen them form ice inside the tubes before which didn't sit well with me.

[3g4u]

the noise thing is one factor but also usually stock intakes have like 2-4 seperate compartments that act as extra protection against water locking.

[Doozer]

Plus, contrary to what a lot of people think, they don't improve fuel efficiency. They increase power by increasing the airflow into the combustion chamber. This actually results in more gas being used. Check any of the intake websites; they'll never claim fuel efficiency gains; only power gains.

[Eleanor]

Originally posted by Doozer
Plus, contrary to what a lot of people think, they don't improve fuel efficiency. They increase power by increasing the airflow into the combustion chamber. This actually results in more gas being used. Check any of the intake websites; they'll never claim fuel efficiency gains; only power gains.

http://www.mopar.com/m_perf_subcat2Check.jsp?SubSubSubGrpID=579&dummy5=1194591324795

[89s1]

Teggypimp: the only cars that dont gain from an intake had nothing to gain in the first place.... and you read too many "peak gain" websites. a good CAI could gain 10 horses no problem, but only peak 3 or 4

Doozer: just wrong

[The Cosworth]

Originally posted by 89s1
teggypimp95: Wrong.

Doozer: Wrong

but you both get points for attendance :angel:


care to elaborate???


I agree with the fuel consumption, if you can pull more air into the cylinders you have to add more fuel to keep it going otherwise it will run lean.

[89s1]

i was editing for elaboration when u quoted me...:angel:

an engine that makes more power doesnt take as much work to move the vehicle... you may find yourself accelerating up to speed at the same casual pace but using less throttle angle to do it.

[cressida_pimpin]

When I added a CAI to my old car I got an extra 90km/tank and the air filter before it wasn't clogged.

[89s1]

Originally posted by cressida_pimpin
When I added a CAI to my old car I got an extra 90km/tank and the air filter before it wasn't clogged.



:werd: I got insane mileage driving my 191bhp 89 civic here from Manitoba. Around 6.5 L/100kms

more power, less effort for motor to move said car.

[89s1]

Originally posted by 3g4u
the noise thing is one factor but also usually stock intakes have like 2-4 seperate compartments that act as extra protection against water locking.

those are usually for noise reduction actually.

[Doozer]

Originally posted by Eleanor
http://www.mopar.com/m_perf_subcat2Check.jsp?SubSubSubGrpID=579&dummy5=1194591324795
Link didn't work, so .... :dunno:


Originally posted by 89s1
i was editing for elaboration when u quoted me...:angel:

an engine that makes more power doesnt take as much work to move the vehicle... you may find yourself accelerating up to speed at the same casual pace but using less throttle angle to do it.
WTF? So where does this "more power" come from? It magically makes more power without consuming more fuel? That is one HELL of a performance upgrade!

Now, in all reality, perhaps there is some way that an intake can add more power simply by consuming more air while burning less fuel, but this one I'm going to have to hear the full explanation because I don't see it.

[89s1]

did you read my posts?

[Doozer]

Originally posted by 89s1
did you read my posts? An excellent response. Sadly, I did, several times, which is perhaps my own fault.



Originally posted by 89s1
doesnt take as much work to move the vehicle
This is one of my favourites. Apparently you've ignored Newton's second laws of physics. In this context, it basically state that something of the same mass, under the same forces, takes the same amount of energy to move it every time [here's a link (http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/newtlaws/u2l3a.html) ]. So, while it's true that an engine that makes more power has an easier time moving an object, that "more power" has to come from somewhere. And if you think it's coming solely from the extra air provided by an air intake, you're sadly mistaken.

Wikipedia says: http://en.wikipedia.org/wiki/Cold_air_intake "All cold air intakes operate on the principle of increasing the amount of oxygen available for combustion with fuel. Because cooler air has more density for a given volume, cold air intakes generally work by introducing cooler air from outside the hot engine bay."

I think we can both agree on that? Cold air intakes bring in more cold air.

Now, not only is there more air to burn, but the air is also more dense (cold air is more dense than warm air). Both these factors will cause more fuel to burn. More air, and an increase in the air density.

So sometimes there is validity to some of the claims of an improvement in "overall engine efficiency", but that's not the same as "improved fuel economy". Sure, an engine might only use 1L of gas to make 170hp with an intake, instead of .98L to make 160hp without. So overall, the engine is more efficient with the intake. But you're still using more gas than you would've before the intake, and that's the point.

In forums like this, most people are willing to make that trade-off, because it's usually a favourable compromise in terms of power and engine efficiency. But in terms of overall fuel savings, you're still coming out worse.

[Destinova403]

Originally posted by Doozer
An excellent response. Sadly, I did, several times, which is perhaps my own fault.



This is one of my favourites. Apparently you've ignored Newton's second laws of physics. In this context, it basically state that something of the same mass, under the same forces, takes the same amount of energy to move it every time [here's a link (http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/newtlaws/u2l3a.html) ]. So, while it's true that an engine that makes more power has an easier time moving an object, that "more power" has to come from somewhere. And if you think it's coming solely from the extra air provided by an air intake, you're sadly mistaken.

Wikipedia says: http://en.wikipedia.org/wiki/Cold_air_intake "All cold air intakes operate on the principle of increasing the amount of oxygen available for combustion with fuel. Because cooler air has more density for a given volume, cold air intakes generally work by introducing cooler air from outside the hot engine bay."

I think we can both agree on that? Cold air intakes bring in more cold air.

Now, not only is there more air to burn, but the air is also more dense (cold air is more dense than warm air). Both these factors will cause more fuel to burn. More air, and an increase in the air density.

So sometimes there is validity to some of the claims of an improvement in "overall engine efficiency", but that's not the same as "improved fuel economy". Sure, an engine might only use 1L of gas to make 170hp with an intake, instead of .98L to make 160hp without. So overall, the engine is more efficient with the intake. But you're still using more gas than you would've before the intake, and that's the point.

In forums like this, most people are willing to make that trade-off, because it's usually a favourable compromise in terms of power and engine efficiency. But in terms of overall fuel savings, you're still coming out worse.

you fail to take into consideration the availability of fuel to the engine. *theoretical situation* lets say the injectors are only giving 1 L of gas per hour... either way they are only going to give 1 L of gas per hour no matter which intake you have on there... so arent you just using that SAME 1 L to do MORE than if you had the stock intake... which would make it more fuel efficient right?

from my understanding it causes the fuel to burn more efficiently... so instead of burning say... 98 percent of the fuel in the chamber... you are now burning 100 percent...

that said in practice... i HAVE clocked an increase in fuel efficiency from my Prelude after i put my intake in... its an Injen CAI.

just my $0.02 who knows maybe im completely wrong... :dunno:

[89s1]

I'm clearly retarded, and so is everyone that has ever claimed mileage increases after modifications.

Guess I'll just spend the next few hours attempting to bite my ear.

:closed:

[The Cosworth]

Originally posted by Destinova403


you fail to take into consideration the availability of fuel to the engine. *theoretical situation* lets say the injectors are only giving 1 L of gas per hour... either way they are only going to give 1 L of gas per hour no matter which intake you have on there... so arent you just using that SAME 1 L to do MORE than if you had the stock intake... which would make it more fuel efficient right?

from my understanding it causes the fuel to burn more efficiently... so instead of burning say... 98 percent of the fuel in the chamber... you are now burning 100 percent...

that said in practice... i HAVE clocked an increase in fuel efficiency from my Prelude after i put my intake in... its an Injen CAI.

just my $0.02 who knows maybe im completely wrong... :dunno:

The injectors vary the amount of fuel based on a number of parameters (depends on how your car is set up) but they usually are, MAF sensor, MAP sensor, TPS Sensor, O2 Sensor, Knock Sensor (i am not sure if I am fogetting any other ones) so if you put on a CAI, more air will be coming in (or at least denser air) so the MAF, MAP, and O2 sensors notice this increase and bump up the amount of fuel being injected accordingly to keep a stoichiometric burn (or close to)

The only reason I can think of edit cause I am a tool: DECREASED fuel consumption is that you are actually driving your car slower, this could be due to the fact that the intake is making a bunch of noise so you feel like you are going faster than you are

[Doozer]

Originally posted by Destinova403

either way they are only going to give 1 L of gas per hour no matter which intake you have on there Just like Brendan says above, that's not entirely true. With new cars, more oxygen means the car will automatically adjust the fuel delivered to the combustion chamber. Otherwise, I'd agree with you.


Originally posted by 89s1
I'm clearly retarded, and so is everyone that has ever claimed mileage increases after modifications.
Some modifications, absolutely. I'll give you that. Just not an air intake. Combined with chip programming or some of a million other mods, anything's possible, including improved fuel efficiency.

I'm not arguing your own claims in better numbers either. I'm just saying that if nothing else changes (including driving habits, etc) a cold air intake alone doesn't improve your gas mileage, no matter how you slice it. It's just not physically possible. :dunno:

[89s1]

Being that I drive an older car, AND my ecu is aftermarket, I suppose that I'll agree with you doozer that what happened in my case may not happen across the board.