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Noob here. Looking for info on why cold air intakes are a waste of money...or not

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6K views 39 replies 12 participants last post by  olerodder 
#1 ·
Can someone with knowledge on the subject explain why a CAI is a waste of $? Or conversely, why they actually work?

I would appreciate any info.
Thank you in advance.
 
#2 ·
Because I'm too lazy to type, I copied this quote that might help you...

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. What many view as an issue (is the plastic intake tube withits noise canceling design) actually increases air pressure. It is the samehydraulic concept used by fire fighters creating water supply where psi is low.By having the air cross the path at a 90 degree angle, the pressure isincreased proportionally. Fire fighters use what is called a “4-way valve” or“Blake Valve” at the hydrant where the water is cycled through the fire engine(pump) and sent back into the valve crossing the water flow at a 90 degreeangle. In this case it also acts as a sound canceling device! At low speeds,this can reduce the flow a tad (which is what most “feel”), but in terms ofpeak hp/tq, a good high flow filter is all that is needed....again, basicphysics.



There is simply no way any CAI on a relativelystock engine can increase the air flow enough to exceed the ECM’s ability toadjust and maintain the correct fuel mixture. The only reason for the “custom” program to support the CAI is becausethe design is poor resulting in false readings from the air intake sensors, etc….period! The OEM software system is designed to adjust the fuel mixture up to 10%(25% on the 2000+ mod engines).......that’s more than enough to handle fuel mixture adjustments up to 7,000 foot elevation change! (for high elevations 8,000+ there are oem software programs for those specific applications).

This is reinforced by both Arlen Spicer and Ford.....


Testand Corporation conducted an ISO standards test onautomotive 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."


In 2012 on jay Leno’s garage, when inquired, Fords Mustang Chief Engineer DavePericak specifically stated that the use of an aftermarket CAI will do nothing to gain any power.

http://www.youtube.com/watch?v=4LXYK4rR7Sw
 
#5 ·
Can't argue. I've been hotrodding cars and bike and building up engines for decades. It's not new rules here. An engine can only take in as much air as its displacement, cam timing, manifold flow and overall VE can allow.

Most of us made the same stupid mistakes when we were young, in the pre-EFI days, slapping a 750 double pumper on a 289 C-code.

EFI makes life easier by eliminating the need to keep fuel suspended in the intake stream but, the principles here are the same. outside air pressure is approximately the same in most operating environments the car sees (this is N/A's "forced induction"; around 14.7 pounds per square inch. On top of that is what the motor can draw based upon the above. In the example I used, the 600 vac secondary was still more carb than the 289 needed but you could jet it into much better performance than the 750 DP.

Real modern world? I put my 2012 BBP into the 11s at 115 on a mild tune a tire, through the stock paper filter and exhaust.
 
#7 ·
Most of us made the same stupid mistakes when we were young, in the pre-EFI days, slapping a 750 double pumper on a 289 C-code.
Guilty of that here. I thought a Holley 650 cfm was perfect match for mostly essentially stock 302 on my Mustang II. I finally learned the Holley 600 was a better fit but STILL more carb than what was really needed.
 
#6 ·
Voltwings did a nice science experiment on this but I haven't been able to find it. you can PM him mayhap he remembers where it was.

from everything I've read get one for looks and sound and decide what worth it is to you (for me the $75 I spent on a used one was worth it) but don't spend any $ for performance as it won't be worth it.

Welcome to Mevo
 
#10 ·
Voltwings did a nice science experiment on this but I haven't been able to find it. you can PM him mayhap he remembers where it was.

from everything I've read get one for looks and sound and decide what worth it is to you (for me the $75 I spent on a used one was worth it) but don't spend any $ for performance as it won't be worth it.

Welcome to Mevo
Thanks for the shoutout.

http://www.mustangevolution.com/forum/f356/t373422/
 
#8 ·
Well that settles that then.
Thank you for the information.
 
#12 ·
As Grabber said, everyone was guilty. I had a 48 Chevy in 1968 with mod'd 340HP Corvette motor and 4spd and modified fenderwell exit headers from a ChevyII. Although many of you may not remember the Holley 950cfm three barrel, that is what I put on the motor...only to find out above 5500rpm to redline it was great...took me a while and quite a few spark plugs to finally decide on a 735cfm Holley:facepalm:
 

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#21 ·
That's Kool Rodder. Remember the 3bbl well. I think all us Ol' Farts are guilty of over carbing their sleds back in the day. Talk about reminiscing, how about the old Christmas tree Holly. Used to run those on my 292 and 312's.
Buy a CAI for beauty and sound, you'll be happy. Running the K&N Typhoon on the V6 Cyclone. Sounds good and nice bling when you pop the hood
 

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#13 ·
the "good old days", indeed....glad they are gone.
 
#16 ·
I like the precision that modern technology gives you, but it's also the biggest hindrance in doing a swap or pulling a motor. I'm not kidding, in half the swaps I have done, a good part of the work is just pulling out the damn wiring harness. Not to mention you cant do a motor swap these days without a control pack adding 2-3k to the price.
 
#18 ·
The end result has to be considered as well. You get way more power way more efficiency and no driveability problems. You and the machine is just rose-coloured glasses thinking. You assuredly felt differently back in the day every time you had to push your 4000 pound heap out of an intersection because it quit running for some reason.
 
#19 ·
My 71 Chevelle had a high rise intake with two 750cfm carbs. It had to be pushed once, and that was because I ran out of gas.

Tuning both carbs was no fun at first, but once I understood how it wasn't so bad. I also realized that I needed the smallest jets possible.

A points and carbed car is simple. If there is a problem, finding it was usually locating a bad plug, plug wire, distributor, or the points. You could see the fuel flow through the clear filter. The fuel pumps were mechanical. The most that could co wrong with a carb was a clogged jet, stuck float, or bad o-ring.

Setting the timing was nothing more than a strobe light, timing marks, and the slight turn of the distributor.

If I wanted a larger engine, I didn't need to worry about an entire wiring harness. My steering, brakes, and fuel were directly controlled, not servo controlled. The guages worked with anything as long as you had the right fitting.

I'm not that old. I've just worked on a lot of older engines.
 
#22 ·
I love modern technology as long as I don't have to work on them. I had fun with my 2014 TrakPak Mustang doing suspension mods and attempting to tune it although my ATS-V is just as much fun to drive and rides more comfortably, can take 4 people in a lot more comfort than the Mustang.
Some of us old guys grew up tuning by ear, with a vacuum gauge and timing light, building headers and working on carburetors. My last 9.80's drag car had a single Holley and 2spd Auto, easy to tune and maintain...no computers or weather stations for me and I had the time of my life for 40+ years. For me it was and still is the greatest time of my life!
As for 4000lb heaps...have no idea what you are talking about because I drove "real" hot rods, Camaro's, Mustang's, Pontiac TA and Dodge Dart Sport type cars and none of them weighed more than 3200/3300lbs...in 1976 the TA did 13.2 in the 1/4 through the mufflers with street tires and stock 3.23 rear gears and this was my wife's DD.
Nobody really knows what it was like back then unless you lived it, did you???
 
#24 · (Edited)
Feck yeah, I lived it. My first Mustang was a 1968 coupe.

Let me help all of you remember. I contend cars were **** back then (by which I mean 60s through 80s). Here is some reasons why: Routine breakdowns, often lots of cubes but, relatively, no power, no handling, ****ty steering, rust, no brakes, wobbly body on frame designs that gave way to fragile unit body cars, poor power to weight ratios in many cases (my '74 Trans Am was around 3800 pounds and it had wind-up windows and no AC), horrendous fuel consumption, rust, ancillary systems like lights and wipers ineffective at best, downright dangerous at worst and, did I mention rust?

Here are some things from the good old days we don't encounter any more:

vapour lock
run-on
tire blowouts
water in the distributor
points eroding
broken dashboard "gauges"
gasoline-soaked fingers from every "tune" change

...to name a few. THESE are the good old days, in case nobody noticed. I can diagnose and tune many a car or bike today without turning a wrench. Awesome power, high efficiency, good mileage, durability and overall quality. Look at the times my basically stock cars did in my sig below. Wasn't too long ago I'd need a purpose-built race car to get that.
 
#25 ·
Growing up in the 60's and racing and building hot rods/street cars/race cars was an extraordinary time for me and has never stopped, although I have to admit that being way past 70 working on cars has lost some of it's shine and working on computer operated cars is just not fun for this guy.
So, I'm sorry if you automotive life in the 60's was terrible...for me it was the best time of my life and the memories are still there.
 
#29 ·
.02 on the golden age of cars. This is a golden age (as was the late 60's) but I was a bit young to appreciate the 60's. I will say that today a good number of folks can deal with computers like in the 60's just substitute in the word carburetors. times change but I don't see much of a difference. I will say that todays cars absolutely rock compared to back in the day but I I was given a choice between a new 2018 or a mint 1968 Vette it would be a tough decision (ignoring the get the mint 1968 and sell it) but I think I would go with the new one as driving it as a driver would be nicer/more reliable/etc. My main complaint about todays cars is electronics...back in the day a Holley could be made to work in most anything. Todays black boxes are not real interchangeable which gives them a cost of "but I only wanted one?!?!?!"


cold air intake (on topic)
 
#30 ·
Oorah efi. Even my beater work van (89 g10 Chevy) I chose because it was the first year for efi, and the last year for one of the good things from the 60s, the turbo 400 3 speed auto. That thing is often parked for long periods, sta bil, a full tank and disconnect the battery is the extent of prep.

I've been running e85 in the mustang lately. It loves it. It is actually a tune for 150 shot wet nitrous but it runs really well off the bottle, surprisingly, unlike my gas nitrous tunes.
 
#32 ·
CAIs increase the volume of air entering the engine compared to stock; however, they also increase the temperature of air going in.

Voltwings and another member did a test on acceleration with stock air box, Steeda CAI, then Steeda and a tune. Same values for both units. Only the tune improved performance.

As has been said before, a CAI is for looks and sound only.
 
#33 · (Edited)
I would like to expand on this since this thread came back up.

First, even if the temperature increases, if the mass has increased (meaning the reading at the MAF is higher) then you are still getting more air. Our testing did show that both temperature AND mass increased, so we were getting more airflow. That being said, on an otherwise stock vehicle you are correct, we did not really see "performance" gains (meaning decreases in time covering the same distance) until the tune was added.

One thing that i would like to address, but is probably hard to test in a controlled manner is throttle response. I would bet that an open element filter will increase throttle response and "tip-in."
Sealed, "pressurized" airboxes are good at speed, but they do cause a restriction at "tip in," especially from a dead stop. So, while an open element filter may not increase MAX airflow, i would bet that at various points in the curve, during part throttle conditions, there would be gains in airflow and response... again though, something almost impossible to test with any sort of accuracy or consistency.


My purchase of a new Chevy Colorado is what got me thinking on this tangent. The Colorado has a fender snorkel similar to the old 2v design, and the thing pulls very nice when i am already moving, but the throttle response and top-in suck... I'm debating throwing an open element filter on this thing just to get some throttle response out of it.
GM performance will even sell you this spiffy filter and 5 sided airbox for the low low cost of an arm and a leg -_-

http://www.gmperformancemotor.com/parts/23342235.html
 
#35 ·
I ran a data log on my brothers truck last night. It was 50° out, and the intake air we were getting with the truck at speed was 20° higher. With the truck stopped the temp increased, quickly.

I can imagine the results are much worse in the summer.

I did this test on my 02 GT a while back, during the summer. My factory airbox drew in outside ambient air temps. At idle the temps did not raise by much.
 
#37 ·
Absolutely. You can't have more mass flow without gains. More mass air flow means more fuel consumption, which means more power. The problem with the Coyote engine is the stock intake is sufficient by a good margin for the maximum air the engine can ingest. It ain't the 80s anymore.

Super-huge swag/ballpark 10 flywheel horse for every extra lb/min on a really efficient engine. That is MAJORLY oversimplifying something that hugely varies depending on the engine and many other factors but, thumb-up, one-eye-closed....
 
#38 ·
Lol, the coyote is one of those engines. One of a few engines capable of producing over 1.0 load, meaning it's capable of over 100% VE due to trick cylinder filling / ram effect from good vvt. 1:10 is a pretty good ratio on this engine, but yes like you said, it is still all "on paper."
 
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