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23

Lean ≠ More Air I believe the source of the misunderstanding is in how the term "lean" is being interpreted. A lean mixture doesn't indicate the presence of more air. It indicates the presence of a higher proportion of air compared to fuel (air-fuel ratio, or AFR). Quick example Mixture A has 1,000 g of air, 80 g of fuel. AFR = 1000/80 = 12.5 ...


19

Does this mod ever give a measurable increase in power? tl;dr: yes, sometimes it works well. But... Your picture is a good illustration of some of the problems with just saying "cold air intake" and expecting that to mean the same thing to all people. Let's break down the pieces of the puzzle and talk about how those might help or hurt: Filter: notice ...


13

MAP = Manifold absolute pressure and is a sensor to measure vacuum, the computer calculates the engine air flow based on the vacuum, throttle position, and intake air temperature. The computer also measures the barometric pressure using the MAP sensor before the engine cranks, this lets the computer compensate for altitude, or how dense the air is. Typical ...


10

Variable-length intakes increase the pressure of the air entering the intake manifold thanks to a physical phenomenon called Helmholtz resonance. It's also known as dynamic supercharging since it avoids the use of a mechanical device (compressor/blower) to boost intake air pressure. How the Helmholtz does it increase air pressure? Without getting too ...


10

I don't have any empirical evidence for this, but would say no for two reasons: An air filter will collect more dust, dirt, and debris until it gets so full that it starts pushing the older dust, dirt, and debris through the filter, which is what you are trying to prevent in the first place. As the air filter collects more dust, dirt, and debris, the ...


10

It will have no affect on the longevity of the engine or components as long as you get one with a decent filter on it. You'll have to check reviews on different elements to ensure you are getting one which is good. We'll not mention which ones I think are better, as that gets into the realm of both shopping and opinion. In and of themselves, CAI's will not ...


9

Normally the idea is to get more air into the engine using a less restrictive air filter. As an engine is basically an air pump, getting more oxygen and more fuel into the engine usually equals a bigger bang and thus hopefully more power. That said, in order to get a meaningful improvement using a performance air filter, the main restriction needs to be the ...


9

The point is to feel like you've done something cool to your car and freed it from the shackles of The Man/the OEM intake. The primary benefit of Cold Air Intakes is to the bank account of the kit manufacturer, the secondary benefit is your car making a nicer noise, if you like the sound of an aftermarket intake. There's been a few debunkings of CAIs over ...


9

The 'floating' intake runners are moved by a mechanism, coupling and decoupling them from the main intake runners to increase the overall length for better low RPM performance. This process was recently discussed here: mech.SE on inlet runner length I don't see that having the extension pieces in the decoupled position would have any effect of the resonant ...


9

It all depends on what you mean by getting better. It is possible that, as the very small holes in the filter that let air through start to trap particles, the places where air can get through will get smaller and smaller. Therefore the filter will start to trap smaller and smaller particles. The air filter may get more efficient at filtering, but it will ...


8

Lean operation vs exhaust catalysts: The three-way catalytic converter fitted to gasoline vehicles can't operate under lean engine conditions because the reaction of NOx to nitrogen and oxygen is a reduction reaction, and for this to occur there needs to be a corresponding oxidation. In the three-way catalyst that is the oxidation of CO and hydrocarbons to ...


8

This is a variable-length intake Variable-length intakes increase the pressure of the air entering the intake manifold thanks to a physical phenomenon called Helmholtz resonance. It's also known as dynamic supercharging since it avoids the use of a mechanical device (compressor/blower) to boost intake air pressure, which means the air enters the cylinders ...


8

Some people think that a cold air intake will generally improve engine performance, allowing fuel to combust at lower temperatures, increasing fuel efficiency. They believe the lower temperature is actually better for the engine. Performance air filters, if you get a good quality one, might typically allow more air flow while reducing foreign particulate ...


8

It's a silencer. It's used on the intake tract to deaden the noise of the air as it goes through the intake. It usually isn't needed, but if taken off, you'll need to ensure the hole is completely plugged. If you don't, unfiltered air will enter your intake and cause issues. EDIT: For more information on the phenomena of how the silencer (resonator) does ...


7

The oil stuff is more than likely caused from what the intake pulls out of the crank case through the PCV. If you can get a hold of a couple cans of Seafoam, this should take care of the residue about as easy as you can do it without taking the engine apart. Use the rubber hose to the right of the photo to introduce it into your system. As an engine gets ...


7

Would there be a substantial enough of a horsepower boost to be noticeable? The most you could see from such a modification is 15hp. This would not be enough for the seat dyno to register, unless there are plenty of hemorrhoids to detect it. More then likely you'd see a measly 5-10hp, and then only at the higher RPM levels would this be apparent. You would ...


7

It depends. Just because an intake can flow more air mass doesn't guarantee that the engine will utilize it. The intake is part of a system of components. The engine produces power by managing air flow into and out of the combustion chamber. There are usually other actors involved: Intake side. Carburetors, throttle bodies, intake manifolds, intake valves,...


7

It's not that the catalytic converter can't handle more air per se, it's that running lean increases the temperature of combustion (I actually don't know why, but now I'm curious) and the catalytic converter needs to run inside it's chemical operating range. Something to do with the chemistry that I also don't know. As for advantages for turbo boost and ...


7

I agree with @JPhi1618 that it is related to the MAF sensor. From the picture you provided in your comment, it appears your (really good looking) MSR intake comes with its own MAF sensor housing. I too am unfamiliar with this car, but the MAF housing on your new intake is likely a different diameter than the OEM housing. This causes problems, as your OEM ...


6

It sounds as though you did suck up some water and were on the verge of hydrolock, but didn't quite get there. I also doubt you have caused any damage to the engine, in fact, you may have inadvertently helped your engine (though I wouldn't suggest you do this again!!!). The extra sputtering may have been a case of the filter on your CAI getting soaked with ...


6

Two things come to mind here: First, cars are a sieve. There are more holes in them than you can shake a stick at. Lizards are very pliable creatures and can fit through any of these small openings if it fits their needs. Second, the lizard may have been in your car since the last time you were in your car. You never know.


6

The length of the intake runners have certain affects on the engine operation. For example, longer intake runners are used to improve the bottom end torque (torque at low RPMs) while shorter intake runners will improve top end power (horsepower at high RPMs). The lengths will vary from engine to engine as well as what the goals of each vehicle the engine ...


6

You guys are looking at it from the wrong angle... It’s not about the carb or the ram sur effect, it is all about the exhaust. The exhaust side of the cylinder is the hottest side so it needs to be facing forward so it’s gets a bit of cooling. Plus if you’d put the exhaust facing backward it could get too warm where the cables and electronic are, under ...


6

First of all by "most production motorcycles" I am assuming commuter level motorcycles used in South and South East Asia its not true that all production motorcycles have intakes facing backwards, its more or less a ergonomics based design decision , some motorcycles have intakes facing 90 degrees to the side. Some have them facing towards the back as you ...


6

Specifically a foam filter for a lawn mower needs oiled, but just lightly. A foam filter lacks the ability to stop small particles as compared to a paper filter. The oil is added to make the filter "sticky" to these small particles giving the foam filter better filtering capability. As far as major engine damage, probably not. Worst case scenario the engine ...


6

I believe that what @JPhi1618 stated is a major factor in your rich condition: Could the different air flow path cause issues for the MAF which would have been tuned specifically for the stock intake? And that this statement that you made to counter I believe not to be true: BMW uses the same Bosch `MAF` sensor on all turbo cars. I highly doubt they ...


6

No. Simply put, the throttle body is the physical device that controls engine speed. Thus the name "throttle body" because it throttles the engine. In essence, if you took the plate off, the engine would run wide open (max RPM) and you would have no control of the engine speed. It is more complicated than that because there are sensors detecting the air ...


5

Moves.. answer is a good one but you asked about advantages/disadvantages of MAF sensors. Disadvantages are: the sensor sits in the intake and thus restricts airflow. Airflow restrictions translate to performance restriction, particularly with vane style air flow meters. A simple example of this is the comparison between a Subaru STI MAF sensor and a ...


5

tl;dr: your car will be more vulnerable to hydrolock. Don't use full throttle in deep puddles. In the rain, you should be fine in most situations. All that said, you'll still be able to ruin your car if you try hard enough. If you submerge a running car in water, it's going to damage the engine, cold-air intake or not. One of the worst possible ...


5

depends on if you have carburetors or fuel injection If you have a carburetor Cons You will make the bike have a lean condition Backfire on deceleration More oxygen will create more engine heat and this will cause additional wear on components You could burn your exhaust valves Pros You could buy a jet kit and pipe to go with it and get a few extra HP ...


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