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CAI - Cold Air Intake - No Benefit

13K views 44 replies 18 participants last post by  Ruffy07 
#1 ·
I posted this on another forum and figured I'd make the same point here. Anyway, I've always wondered about adding a CAI and have been told repeatedly that these days they are a waste of money. I'm inclined to agree, but I'm not going to say anything on the issue. If you're interested in what Mustang Chief Engineer Dave Pericak has to say about it, you can see it in this video. Skip to 4:45 to hear what he says about the CAI. Pretty eye opening.

Drive safe!
 
#3 ·
Suggest more research, if you don't have a new car. What he said was that the CAI doesn't help the new cars. (They tune the engine at the factory for maximum horsepower). I tend to agree that a CAI without a tune doesn't really help. However, the CAI and a tune may be helpful in an older model car. Just something to think about.
 
#4 ·
Love the video...thanks for posting !!!

Later...Dave
 
#6 ·
They sure don't tune at the factory for maximum horsepower. They leave plenty on the table bc of emissions, noise and safety regs. That said, I've put two S197s into the 11s through factory airbox and exhaust.

I can't believe we are still having this conversation; it ain't exactly breaking news. :surprise:
 
#7 ·
Considering how many aftermarket companies are selling them, evidently not. What I want to know is where they get these dyno numbers from. When you see the before and after videos, there's always a major increase that's ascribed to the CAI and to me, it's just not believable. What makes matters worse is when I ask some of these online merchants about this and reference this video, I get no response. Ever.
 
#8 ·
So many ways to cheat on the dyno to mention.....

You could test the factory box on 87 and the tune and CAI on 93.

You could adjust the correction factors to favour the CAI

You can run hood up with the CAI to give it access to colder air

etc. etc. etc.
 
#12 ·
Why has this subject not been laid to rest yet. The factory airbox is good and aftermarket CAI's are mostly for looks and sound. It would be nice if someone did a comparison between the stock air box and an aftermarket one without changing the tune to see if there is any significant change. That will probably never happen though because all those aftermarket companies would lose sales. I'd be surprised if there was more than a 5-10 hp difference between the stock airbox and a CAI.
 
#13 ·
i dont necessarily believe that a cai is a complete waste. i have one on my 14 track pack..i first put it on (airaid synthamax) maybe a little bit of a bump..but after having installed a VMP tune...defintely yes..now i also owned a 08 bullitt which came w a factory cai..as the shelbys did as well as they still do now..makes me think if the ford engineers then and now designed them...well maybe it has some validity..
 
#14 ·
I posted this on another forum and figured I'd make the same point here. Anyway, I've always wondered about adding a CAI and have been told repeatedly that these days they are a waste of money. I'm inclined to agree, but I'm not going to say anything on the issue. If you're interested in what Mustang Chief Engineer Dave Pericak has to say about it, you can see it in this video. Skip to 4:45 to hear what he says about the CAI. Pretty eye opening. https://www.youtube.com/watch?v=4LXYK4rR7Sw"]

Drive safe!
Ford uses CAI style intakes on the gt500's and gt350's. They dont work though. :grin:
 
#15 ·
Ok, let's just take a look at basic physics.....and acompletely separate simple engine.....Fords 5.4 V8 in the F150.....

The2013 Mustang 5.0 V8, for example if close to stock (assuming 6,800 max rpm& 90% volumetric efficiency- note that is race car spec and likely higherthan reality) can only suck in a maximum of 535 CFM, and the OEM flat panel filter ( 12.375” x 9.675”) will flow 718cfm,

....so how can just a CAI force more air into an engine thatis already injesting everything it can? It can't plan & simple- basic lawsof physics without a forced induction system.


Now, why does Ford use a larger filter on the model you suggested....it needs more flow....




The formula which is used by every air filter manufacturerin the world to determine the CFM for flat panel filters is...


Flat Panel CM= Length x Width x 6




So, take you relatively stock engine, calc the max CFM basedupon mfg specs; calc the max CFM the oem filter will flow....now show me howsticking a filter that will flow 900 CFM will increase the performance of anengine that can only suck in a max of 480 cfm and has an oem filter that willflow 500 (like on the 5.4 F150)?




Testand Corporation conducted an ISO standardstest on automotive air filters which can be viewed at this link: http://www.dieselbombers.com/chevrolet-diesel-tech-articles/16611-duramax-air-filter-testing.html. All I can say is this explains in detail thereason for

(Arlen)SPICER, a well known credentialed engineer wrote,

“Now that I am not doing the tests and my objectivity is not necessary, letme explain my motivation. The reason I started this crusade was that I wasseeing people spend a lot of money on aftermarket filters based on the word ofa salesperson or based on the misleading, incomplete or outright deceivinginformation printed on boxes and in sales literature>"
 
#16 ·
Ok, let's just take a look at basic physics........


The2013 Mustang 5.0 V8, for example if close to stock (assuming 6,800 max rpm& 90% volumetric efficiency- note that is race car spec and likely higherthan reality) can only suck in a maximum of 535 CFM, and the OEM flat panel filter ( 12.375” x 9.675”) will flow 718cfm,


....so how can just a CAI force more air into an engine thatis already injesting everything it can? It can't plan & simple- basic lawsof physics without a forced induction system.


Testand Corporation conducted an ISO standardstest on automotive air filters which can be viewed at this link: http://www.dieselbombers.com/chevrolet-diesel-tech-articles/16611-duramax-air-filter-testing.html. All I can say is this explains in detail thereason for

(Arlen)SPICER wrote,

“Now that I am not doing the tests and my objectivity is not necessary, letme explain my motivation. The reason I started this crusade was that I wasseeing people spend a lot of money on aftermarket filters based on the word ofa salesperson or based on the misleading, incomplete or outright deceivinginformation printed on boxes and in sales literature."



The formula which is used by every air filter manufacturerin the world to determine the CFM for flat panel filters is...


Flat Panel CM= Length x Width x 6


So, take your relatively stock engine, calc the max CFM basedupon mfg specs; calc the max CFM the oem filter will flow....now show me howsticking a filter that will flow 900 CFM will increase the performance of anengine that can only suck in a max of 480 cfm and has an oem filter that willflow 500 (like on the 5.4 F150)?


bad math, no science...all PR materials for the sticker hpcrowd!


and specific to K&N, ask me if they honor their warranty.....IMHO, personal experience, no!!!!!!!!!!!!!!!!!
 
#19 ·
Ok, let's just take a look at basic physics........

The2013 Mustang 5.0 V8, for example if close to stock (assuming 6,800 max rpm& 90% volumetric efficiency- note that is race car spec and likely higherthan reality) can only suck in a maximum of 535 CFM, and the OEM flat panel filter ( 12.375” x 9.675”) will flow 718cfm,


....so how can just a CAI force more air into an engine thatis already injesting everything it can? . . .


and specific to K&N, ask me if they honor their warranty.....IMHO, personal experience, no!!!!!!!!!!!!!!!!!
The math shown here is bad math, because it completely ignores the driving force for all fluid flow: pressure differentials.


When we talk about flow through a restriction, the conversation is not complete unless we include the pressure drop. Pressure drop is important because it is atmospheric pressure, less the drop through the intake, that pushes the air into the cylinders. The purpose of any intake improvement is to reduce the pressure drop.


The engine is not injesting everything it can. It is getting whatever is driven in through the intake cycle; and that is always less than the theoretical maximum which would be if full atmospheric pressure was reaching the intake port. (It is more complicated that that due to flow, but that's the basics). That is why forced induction produces more performance -- it is increasing the pressure at the intake port and pushes in more air.


So yeah for practical purposes the aftermarket intakes probably produce very little gain, because the pressure drop through the stock intake is already quite low. But it is not because of this physics / math.
 
#17 ·
Like Beech said - they're trying to sell you something - our cars need exhaust flow long before they need intake flow.... But those open CAI's do look cool on cruise night

Scott
 
#25 ·
It ain't hard when you are flowing something on the bench, to simulate the motive forces here. Brother's right, you can't ignore that but, if we basically conclude that one 5.0 pumping force and 1 earth atmo are essentially similar to another, it's reasonably safe to exclude those variables and have a decent SWAG on the relative effectiveness of adding an aftermarket CAI. We aren't going to see large swings in what one stock 5.0 needs v. another.
 
#26 ·
it's reasonably safe to exclude those variables and have a decent SWAG on the relative effectiveness of adding an aftermarket CAI.
Well, I'm not much of an expert on having swag, but from our debate from today I think it's safe to say that having a cold air intake wont hurt, and it's possible it might even help. Worse case scenario is that it will just look nice.
 
#27 ·
Some do report and aftermarket CAI hurt them. The issue being either a messy/noisy MAF transfer value due to oddball flow characteristics. There is a **** -ton more design that goes into an intake than just slapping the right sized tube on the front of the motor.

....and I'd say that the point of the thread is, if I'd spent a few hundos on a CAI and saw no gains, I'd consider that money wasted.
 
#28 ·
To CAI or not to CAI

I had recently installed a JLT CAI with a 93 tune on my 07 4.6 and noticed a reasonable gain in mid to upper range. Since then I have just replaced that car with a 2012 GT/CS with the 5.0 and I am now getting familiar with that engine. I had planned on adding a JLT CAI and another Brenspeed 93 tune but after reading this thread I have to step back and reassess my plans. JLT is claiming 30 hp gains and I certainly felt a decent bump with the 4.6. But I certainly dont want to spend another 300 bucks just for looks. So basically the 5.0 would not see any substantial gains with an aftermarket CAI over the stock air box, correct?
 
#29 ·
. . . installed a JLT CAI with a 93 tune on my 07 4.6 and noticed a reasonable gain in mid to upper range. . . . had planned on adding a JLT CAI and another Brenspeed 93 tune but after reading this thread I have to step back and reassess my plans. . . . . So basically the 5.0 would not see any substantial gains with an aftermarket CAI over the stock air box, correct?
Yeah I think the basic idea is you saw gains on the 07 because the factory intake on those cars was not as good as the intake on the newer cars. Some are still claiming gains, but relatively small.
 
#35 ·
I datalogged my 4.6L 2V, with a fenderwell CAI (SR brand) vs the stock intake with the snorkel removed and a K&N filter, and my IATS were consistently higher with the stock intake.

The SR would stay at, or a tad higher, than ambient while cruising on the highway.
The stock intake was always 20 degrees or more than ambient under the same driving conditions.

How that related to power, I don't know, never dynoed...but it is worth mentioning that the old fenderwell I had on my 2V (now off) did register lower IATs consistently compared to the stock 2V intake with K&N filter.

Obviously, this is not apple-to-apples to the S197s but it isstill worth mentioning. My engine was getting COLDER air compared to stock...

Does anyone here have actual data backing up all this jibber-jabber going on? Hard data numbers mean more to me than this b***** back and forth about theoretical math problems and such (...btw...I have a B.S in Mathematics, but I would rather have HARD DATA to look at).
 
#36 ·
No kidding huh it was colder?
No hard data here, I don't have a B.S.
Life is kinda BS at times though and cai's kinda are too.
How about the tornado that you stuck into the intake tube that was supposed to make the air swirl as it goes in thus proving mpg's and performance. Those thing was BS but people still bought them.
But I bet the only "hard data" that you'll find are going to be from those selling a product. I doubt too many people add a cai and then run to a dyno.

Sent from my iPhone using Tapatalk
 
#39 ·
Factory air box pros:

- pulls air from the grille (not from the hot engine bay)
- made out of plastic and rubber (less heat soak)
- all the tubing is a larger diameter than the OEM throttle body
- no oiled filter (too much oil can cause MAF issues)
- no risk of inducing water into the engine with '13-'14 vented hoods
- no extra cost because it came with the car

If you have the itch to buy aftermarket parts, get rear control arms to eliminate that stupid wheel hopping! A CAI won't win you a race, but traction will help.
 
#41 ·
I WAS looking at the Steeda CAI since it hooks up to the front air duct. But now, after reading all of these posts and links I think I am going to have Steeda write me a stock 93 tune and see what happens. Decisions, decisions.....:surprise:
 
#42 ·
So here's some new information, third party and I believe completely unbiased:

Grassroots Motorsports is working on an S197 mustang track car project. As part of this project, they installed the K&N intake along with MRT H-pipe with free flowing cats. (unfortunately no they did not do the K&N airbox by itself)

They dynoed the car with those mods, with the factory tune, and got 398 RWHP versus 376 before the change. So they picked up about 22 HP; don't know how much was from the intake and how much was from the exhaust but I'd guess about half and half, meaning about 10 HP for the intake.

So that's consistent with the theme -- not a huge improvement, but there is some.
 
#44 ·
Was the 376 and the 398 on the same day? If so you might have something there.
Do you still have your factory airbox? If you do you could put it on the next time you go to the track as an experiment. That'd be pretty decent "hard data" I think. I realize the weather and such would be a variable but I think it'd tell you something. Just a thought.


Sent from my iPhone using Tapatalk
 
#45 ·
OK, so I'm probably gonna get blasted here for committing blasphemy >:) but after doing much research I decided to go with the Steeda ProFlow CAI and their 93 tune. I dont have the time nor the resources to try different things. I am not even sure how much the addition of the CAI over just adding a 93 tune helped but the kick in the ass evaluation tool, which is free by the way, says that this 5.0 woke up significantly. In the looks department it looks awesome. Steeda is a well respected company and I am sure that they have done their homework, marketing aside, when developing their CAI's. pokebee.gif
 
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