Do Cold Air Intakes Increase Horsepower?

[@EngineeringExplained]

I graduated with a BS in mechanical engineering. Most of my videos I've learned myself by reading and watching everything I can find on autos.

[@djdanzo206]

💯🙏

[@spacemanspiff0365]

Not gonna lie, spaced out a bit while u were teaching. Will rewatch the video

[@EngineeringExplained]

Shaun Whitehair Some times I'm monotonous. I make up for it when the cameras are off. :)

[@RubenRodriguez-tc9lz]

Shaun Whitehair Me too dude, I've learned a lot off of these videos and some of them have also helped with my insomnia. It's a win win situation, thanks Engineering Explained!

[@UnstableAdrianHD]

thought that was just me.

[@johanwelthagen1059]

+Shaun Whitehair 3.3%

[@erkdoc5]

+SpaceManSpiff 03 That's his plan. More views for him.

[@bingobango170]

I ran a duct from my intake, out through the hood , wrapped it around to the inside of my open drivers window to just in front of my A/C outlet. I blast air conditioning freezing air into it and get 100 extra horsepower

[@jurj97]

Bingo Bango leems segit

[@haZedxClanz]

Genius

[@miguelnunezrivas508]

Bingo Bango holy crap someone tht actually knows wtf he's doin lol

[@rosegold-beats]

or you install a turbo

[@buzzcrushtrendkill]

Wow. So hows the perpetual motion machine coming along?

[@EngineeringExplained]

Best free teacher ever. Need to make myself a plaque!

[@DarthVato2010]

Great video however, keep in mind I have to take off my boots just to count to 20.

[@CallMeJeff]

Underrated comment

[@freyermx292]

I have learned more from watching 10 mins worth of your videos than I learn in a whole 7 hour school day

[@ethanheitz4489]

Lol right? What teachers should actually be doing right here. I took 2 years of auto class in high school and this guy taught me more than any of that.

[@Sunsetwithlotion]

Ong

[@TheBanjoShowOfficial]

They don’t teach you about cars for 7 hours in school. Maybe that’s why genius.

[@Sunsetwithlotion]

Thats the most ignorant comment of all time

[@psychoalert1823]

@@TheBanjoShowOfficial in my country where the type of high school i go in, has the option to teach a profession sich as engineering, electronics, medical stuff and more. That might sound good but in reality out of 7 hours (in Wednesdays, where we do only engineering stuff) they took 4 hours to explain how a clutch works.

[@samfazzari4208]

As mentioned before, the automotive engineerings who design the air intake system do a good job at designing the intake system to meet their goals. However squeezing hp out of the engine is rarely their goal. In most modern application emmison rules drive a large majority of the design. Another large concern is sound level. Even performance cars have fairly low intake noise. Therefore, cold air intakes increase horsepower by changing the design to focus solely on performance. Some of these gains are from decrease charge temp and others are from improved flow characteristics.

[@ScannerDanner]

you are well spoken and clear, I just stumbled on your site. nice work! It is a shame that most kids that put these on their engines have them installed to pull in under hood temp air. Completely defeating the purpose of it.

[@walkerscranger]

***** I think you are referring to an intercooler which is different. An intercooler is designed to lower the intake charge after it has been heated by forced induction.

[@MrHarr0073]

@@walkerscranger No, I think ScannerDanner is actually referring to removing the stock air filter system and replacing with a cold air system. Putting an open air filter inside the engine compartment without getting outside air will use air in the engine compartment. That air will eventually warm up and expand.

[@walkerscranger]

@@MrHarr0073 The person I was referring to has been deleted or remove their comment. I was not replying to Scanner Danner, it was some @***** person. I teach automotive classes at a technical college and I see tons of students doing this misleading addition to their vehicles. I tell them there is no such thing as cold air going into the intake... only ambient air if it is picked up outside of the engine compartment. Yes, the market calls it "Cold Air Intake" but like anything else people take it literally without investigating.

[@PavelShevchuk]

It might suck up a curious kitten and you'll get a cat-back exhaust.

[@EngineeringExplained]

Yes, the volume remains the same. All I'm saying is that 4 liters of air at 300K has the same amount of oxygen as 4.13 liters of air at 310K (with the given assumptions). Thus, 10 degrees equates to 3.3% more air.

[@loubenedictvillaruel352]

Just confused. Aren’t we supposed to feed cold air not hot air, hence the cold air intake system. But based on your ideal gas eqtn, you actually heated the air by 10C not cooled. 310k -273 is 37C.

[@sylertv4522]

Volume sir is not MASS.

[@EngineeringExplained]

Rain water shouldn't be too much of a problem, but if you were to ever run over a puddle or get into decently deep water, you could risk hydrolocking your engine - filling the cylinder with water and then braking the weakest link, usually the connecting rod.

[@EngineeringExplained]

Lies! I checked your channel, you've been subscribed for a month. Cheers

[@EngineeringExplained]

Theoretically it could increase fuel economy if thermal efficiency was improved with more oxygen burning, but the opposite could hold true as well.

[@PaulChoix55]

From experience, there is a difference that you can feel with a cold air intake. My friend and I made one with a simple aluminium plate... because his air filter (pod filter) was simply clamped on the stock hose. By lengthening the hose and isolating the filter, we were able to feel a surprising difference in engine power. It feels more willing than before.

[@u-know-this]

Only true if its a vehicle with no ecu

[@Sleepymazda999]

Same here ! I added a CAI and me and everyone that has drivin my car can feel the difference in the throttle response ! Mind you I had a brand new filter on my stock oem intake

[@MsAsdfgh112]

It's good to see you still posting videos. I have learned a lot thanks man.

[@EngineeringExplained]

Ultimately I would say most are pointless unless the factory tubing is restrictive - I would guess that the vast majority are not restrictive, and that the only "positive" (for a car guy) effect of a SRI would be a louder engine - but this is simply because the silencer box has been removed. They may be of more value once the engine is more heavily modified and requires more air - possibly.

[@MrIrrepressible]

@ralderhali cold air is denser than warm air. Being denser means the same volume of air has more oxygen to burn thus making more power

[@EngineeringExplained]

I tried to keep it pretty simple, it's always good to learn new things my friend!

[@billysgeo]

Yeah, I didn't know it has called that. But I'd rather do without t. It may get stack in the "warm air input" state at anytime (especially in "retro" cars like mine)

[@jr540123]

In the case of my truck all i had to do was simply remove the two rubber hoses going to the intake and run a straight peice of hose to the fitting on the heater hose and the other end to the end where it connected right above the thermostat as a bypass. But like you said it can be as difficult as replacing the whole intake or more just to bypass such a simple system that robs power when its needed for racing purposes.

[@marcs4091]

In my experience, every car is different but on most Japanese cars if the filter is in a place where it can get enough air and isn't to close to the engine sucking up to much hot air them, yes they do make more power at high RPMs.

[@EngineeringExplained]

It acts as feedback to close the loop on the system. If there is oxygen left over, the ECU adjusts accordingly.

[@EngineeringExplained]

Thanks for subscribing, cheers!

[@EngineeringExplained]

I love it, its oil burning tendencies and all. :)

[@EngineeringExplained]

Will trade for STI.

[@EngineeringExplained]

Probably so, yes. Check your electrical system as well, plugs/wires/distributor. Obviously if there's a check engine light that would help.

[@aznminhtran]

This is the best channel I've ever subscribed to. Keep doing what you're doing!

[@EngineeringExplained]

The air temp shouldn't matter as long as it's consistent with the test from each. Yes, you should have a good fan.

[@EngineeringExplained]

Jason, and because it likely wouldn't do anything. Perhaps one day.

[@EngineeringExplained]

If you were to assume that the density of oxygen in air remains the same, as well as the air pressure, then yes. But that's not necessarily true. But there is likely a difference between driving mid-day and at night. Probably small though.

[@EngineeringExplained]

What are you going to retune? The engine can calibrate A/F ratio accordingly based on how much air is coming in, as well as using an oxygen sensor to close the loop. It should be a fairly automatic process.

[@EngineeringExplained]

Feel free to ask questions - I try to make my videos clear to any age group. That said, many things can be confusing if not watched in a particular order, or without pre-existing knowledge. I try to make videos which explain all of the details that work as a system, rather than individual videos that repeat information. Let me know what questions you have, and I'll try my best to help.

[@kananisA75]

can you do a video explaning what unitronic,s-tronit etc etc are ??? btw you are 1 of few that every vid you have uploaded is GOOD keep it up

[@EngineeringExplained]

It's basically the volume of the engine (the amount of space displaced by the pistons). Check out my video on engines. Obviously larger engines have the potential for more power, but you want to size the engine based on what you want the vehicle to achieve (high power vs good fuel economy, etc.).

[@ni213ki6]

Thanks for sharing your wisdom. Strangely due to your approach I understood the math. And I understand the logic. One thing though that people dont instantly realise is. More horse power mods you do the more petrol you use. People think that you can get more horse power from mods using the same amount of petrol. Which simply is incorrect. I basically put a 7 inch air intake in my car. The maf read more air in so it put more petrol in 😵 I was able to watch my fuel gauge move literally in front of my eyes. So... I reversed my mod and then put a cover over half my air intake just before the filter and now I'm saving petrol coz the maf sensor has less air over it. So it puts less petrol into the mix. I'm no mechanic I just thought it was obvious to do that.

[@mibars]

Hydrolock. If you go trough a puddle and you will manage to splash lots of water into air intake (wheel splashes water in all directions, front included) you may end up damaging your engine by trying (and failing) to compress water. Air filter may deform (and possibly fail) from moisture and it will get dirty much faster just from amount of dust sucked in.

[@EngineeringExplained]

Basically, pick whichever you would like. Based on what I discussed in the video: 10 degrees cooler = 3.3% more power; 10 degrees warmer = 3.3% less power.

[@EngineeringExplained]

Yes, they have an excellent video on the subject, hence I tried to take a different approach.

[@Roflsponge]

Ah, yes, I understand how twin-turbos work and twin-scrolls and sequential turbos and all that, but the idea of a supercharger + a turbo hurts my head, and you're great at explaining this stuff! Keep up the good work too, my friend. :)

[@Kaisuke971]

Thanks for the vids guy, i'm a nearly 15 years old dude who wants to know a lot about cars, because i love them. It's a bit easy to learn with you, because you know what you're talking about (i guess) and you explain a lot (i'm french so i need explanations x) ). So in fact it's a bit like puting a Turbo on the car (same type of benefits, like you have more power with the same volume). In fact the Intercooler does the same, but for the turbo, is that it ? So Turbo+Ic+CAI= very fast engine...

[@EngineeringExplained]

What parameter would you change in order to make the most of a CAI? Shouldn't the ECU know when there is more oxygen present?

[@MeanYT]

Not gonna lie all I wanted was a yes or no

[@EngineeringExplained]

I simply subtracted 1 from 1.03 to find the percentage change.

[@tomustangexplained]

A cold air intake does not only reduce interior intake tempratures which helps create horsepower, but cold air intakes (the one i use anyway) have larger volumes of air that go into the engine, my stock intake i had was at least twice as small as the cold air intake i have on now, in wich the engine can put more gas into the air mixture, in a dyno i received 30 more horsepower and 27 more torque,

[@EngineeringExplained]

The louder roar is primarily because the silencer box around the air filter was removed, assuming your stock engine had a silencer box. Most do, as a lot of people don't like loud engines, and regulations may require it. It's nice to hear them breathe though!

[@gwwayner]

Most of the restriction is the paper filter element and tiny stock snorkel intake opening. For manufacturers paper elements are cheaper, and the small inlet opening to the air box is in the interest of quietness. So if you use a wide-open high flow filter located in a separate cool part of the engine bay you can get a 5-10% power increase and a racy intake howl when the revs get up. Cooler air is denser and contains more oxygen.

[@TheSassyLoon]

IT ALL MAKES SO MUCH SENSE

[@EngineeringExplained]

Yes, more air means more fuel thus a more powerful power stroke.

[@mikegsg9r]

I was just driving in the polar vortex here in the Midwest with -20 f before wind-chill and my ait was -5f and my car didn't feel noticably faster, after that experience I won't bother with a cai again, but they can make ur car sound nice.

[@T231Flexx]

Honestly. When I installed my intake system. I obviously felt a difference in throttle response, took the car out stock and then took it out with the intake, I ran people with it and then ran them without it, the difference was major, the people who were smoking me, I was able to close the gap of 4 cars to half a car with just a intake and a vacuum hose

[@EngineeringExplained]

Haha me too! Glad you enjoy the videos and learn from them!

[@HYITHO]

Awesome video man! love the theoretical explanation!

[@EngineeringExplained]

I'm sure there are multiple ways of reaching similar conclusions, I just went with what I thought made it easiest to understand.

[@EngineeringExplained]

Perhaps, though turbochargers typically have intercoolers to cool the intake charge.

[@Bones12x2]

I've always consider CAI's as more of a supporting mod like an upgraded fuel pump or brake lines. Basically, their main goal is to make sure that the true performance increasing mods arent being held back by inferior stock parts? Would you agree?

[@maxnovakovics2568]

My buddy's got the same Acura, he took out his headlight and converted it to a ram-air style intake :p

[@DawsonTyson]

they normally do not workas well as they say they do. a buddy of mine did test on a Dino and found some awesome results. (5 runs each filter. giving you the average) he started with a cheap frame air filter, 208 HP. next he used a K&N high flow high filter, 215.5 HP. took out the stock air box and installed a cold air intake made by K&N, 215 HP Toyota Tacoma

[@StoicOutlaw17]

So a high flow air filter did the same as a cold air intake?

[@DawsonTyson]

@@StoicOutlaw17 A stock air box will almost always provide colder air and better airflow than an aftermarket intake. It is only recommended to buy an aftermarket intake when an intake that houses the filter and MAF/MAP sensor is not present. A K&N stock filter replacement will flow just as much air as any pod filter. So if you have the stock air box and the engine is N/A then spend $50 instead of $200.

[@EngineeringExplained]

1.63-2% sounds very specific. Care to clarify your claim? I'm not stating that a CAI will increase your engine's HP by 3%. I'm claiming that if an engine receives the the same air, at 300K vs 310K, it will have 3% more oxygen to burn.

[@EngineeringExplained]

If it is moved away from a heat source (the engine). Most cars do this anyways.

[@EngineeringExplained]

If only I had a vtec and dyno at my disposal. Any donors? :)

[@EngineeringExplained]

I intentionally did it the way I did it in the video. All I was saying was 4 liters of air at 300K has the same amount of oxygen as 4.13 liters of air at 310K, assuming the gas percentages remain constant.

[@EngineeringExplained]

Yes, I guess I wasn't completely clear on the analogy. All I'm saying is that 4 liters of air at 300K has the same amount of oxygen as 4.13 liters of air at 310K (with the given assumptions). Thus, 10 degrees equates to 3.3% more air.

[@EngineeringExplained]

Fortunately, I only had to take 1 chemistry class (hence I really don't know what I'm talking about chem-wise). If I can't see it I don't like it. Much respect to ChemE, ElecE, and CompE majors, I could never.

[@EngineeringExplained]

Probably true. I oversimplified in order to reach a conclusion, but I welcome any feedback that shows differing conclusions - chemistry has never been my forte.

[@EngineeringExplained]

Ha, that's directly converting 10 Celsius as in 10 degrees above freezing. Incrementally, 10 deg. celcius warmer would be about 18 deg Fahrenheit warmer.

[@EngineeringExplained]

Don't have a video on twin-chargers yet. Or twin-turbos. Or twin-scrolls. Or VGT's. Haha, I've got some work to do on forced induction.

[@PippeML]

Thanks man, this video shows exactly what I wanted to know, maybe check out and tell us about the non linear version of the cool air-fuel consumption - hp produced :) great vid!

[@EngineeringExplained]

I believe you mean large bore vs large stroke, displacement remaining the same. Likely longer stroke would ultimately give more torque, but with a smaller stroke you can typically rev higher, thus creating more power. That said, there could certainly be engines which do the reverse of what is typical.

[@EngineeringExplained]

You've misunderstood the video, you may want to watch again. The colder air can hold more volume. A 4 liter engine with air at 300K can hold the same amount of oxygen as a 4.13L engine with air at 310K.

[@EngineeringExplained]

Well the possibility of sucking something into your engine is quite greater; you definitely want a filter! Dirt, rocks, water, etc...

[@jr540123]

If you can bypass it that would help with lowering the temperatures as well.

[@EngineeringExplained]

Cold air is more dense, assuming pressure hasn't changed (this video shows that relationship). But at sea level you'll have more air (from higher pressure) than up in a mountain, which would obviously be colder.

[@EngineeringExplained]

3.3% more air means 3.3% more of every element in that air. If every element has 3.3% more, you would have 3.3% more air.

[@EngineeringExplained]

I believe EcoBoost just means turbocharged and direct injection. Allows for more power in a smaller more efficient package.

[@loulecaudey4704]

To go a bit further in that matter : we're talking about injection. Air and fuel remain separated until they meet in the combustion chamber... On a regular carburetor engine, the air being sucked in carries the fuel drops with it. And in contact with the cold air (which temperature can drop way below zero) and cold manifold walls, these drops tend to condensate, which reduces a lot the efficiency of the combustion. Can even lead to carburetor icing... So on carb engines, cold intake air sounds contra-productive too, would you maybe calculate the "turning point" or "critical temperature" below which it stops to be a good thing and becomes a bad thing for carb engines ?

[@EngineeringExplained]

I say leave it as is, the company that made the car wanted it to be as efficient as possible.

[@EngineeringExplained]

3.3% more air means 3.3% more of every gas that air is made up of, providing an overall gain of 3.3%.

[@EngineeringExplained]

I simply explained the logic hear. It's very likely that many times you won't gain anything. It's important to find (or create) good data showing the improvement.

[@roshaun909]

You forget to add that humidity plays a big part in making power as well.

[@titaniumsandwedge]

Your application of the ideal gas law is correct but the fine details are not. V (volume) is not the independent variable, it is n, the molar flow rate of air into the engine. Each intake stroke of an ICE takes in the same volume of air. At cooler temperatures, the density of the intake air (n/V) is higher than at higher temperatures. Consider an engine running at 3000 rpm. It is sucking in a constant volume of air. If there are more moles of O2 in this constant volume, more fuel can be injected leading to more power. You are correct and wise in sidestepping the effectiveness of cold air intakes. The most good they do is to fatten the wallets of the manufacturers. All the air that comes into a car's intake is from outside the vehicle. The flowrate is large. It is neigh impossible for this volume of air to pick up any appreciable heat from within the engine compartment. The air is moving just too fast.

[@EngineeringExplained]

Mechanical engineering, most of this stuff I've researched on my own though.

[@EngineeringExplained]

Same amount of air by volume taken in, more air by mass since it's more dense. You are correct.

[@EngineeringExplained]

Not exactly sure; could be EGR or just a way to heat the engine up. Warm engines are more efficient.

[@EngineeringExplained]

All I was saying was 4 liters of air at 300K has the same amount of oxygen as 4.13 liters of air at 310K, assuming the gas percentages remain constant.

[@EngineeringExplained]

I believe you meant to post this on my nitrous video? Yes, it uses the same fuel pump, which needs to be capable of handling both.

[@EngineeringExplained]

Nope, North Carolina. But I might live in Oregon.

[@mrelectron6220]

I know Im late to the game here but what I'd like to see since most computer systems monitor air intake temperature. I'd like to see the air temp being pulled in via of the ECM with the stock air system and than install the so called cold air intake and see what the ECM sees with that installed. This would at least end the argument if it indeed pulls in cooler air or not. For one thing most factory air tubes are rubber and offer some insulation to engine bay temps vs metal tubes which are great at transferring heat.

[@ihateliberals518]

for Honda guys, instead of putting the metal tube for a cai, or short ram, just get a factory type r intake tube. it has smooth walls and radius. don't let the outside fool you, it flows very good, then just put your cone filter on it, and get fresh air from outside of the engine bay, then get rid of the lower portion of the air box because it's very restrictive, and you lose a bit of unneeded weight too. for added smoothing of the air, get a velocity stack, they aren't heavy, and it helps smooth out the air

[@EngineeringExplained]

Thanks Mike!

[@EngineeringExplained]

You could likely remove the air filter box and have the same effect. That said I certainly wouldn't recommend it as the filters are likely cheaper.

[@EngineeringExplained]

The one that doesn't require medicine...

[@EngineeringExplained]

You could just leave it as is, or some make splash guards for the filter to prevent any issues.

[@EngineeringExplained]

And 3.3% is a percentage, and as a percentage there will be 3.3% more oxygen.

[@JimmyMakingitwork]

I just like the way it goes, BOoooWwaaaaaaaaaaaaa, when I mash the gas.

[@plastmakers]

Great videoes!! I understanded that things and principles before but thank to your videoes I can remind them and improve my english as well. Thanks.

[@EngineeringExplained]

I wouldn't say most CAIs have no bends. Larger piping perhaps for high revs.

[@Tazwashere19]

Should've claimed that V and R are constant not n and R, and base it on the number of moles of air you are pulling in at different Temp's.

[@Drifting50]

Thanks for the reply. I love your channel, keep up the good work!

[@EngineeringExplained]

Well, you'd have to know the oxygen density at different tempperatures, but yes there could be a small difference.

[@EngineeringExplained]

Well if it is cold air it will affect HP, and if it's not it wont.