The fuel injection runs in closed-loop mode at full throttle (regardless of the engine rpm). Closed-loop means it is not adjusting the fuel/air mixture based upon oxygen sensor readings. Therefore it is possible for the engine to be too rich or too lean at full throttle and it will not even know it. Also, the Mass Air Flow sensor (MAF) is one of the main sensors used to determine fuel charge at wide open throttle because it is one of the more accurate ways to measure airflow. It's primary weakness is that it is easily fooled when airflows have resonant induced pulses (rapid changes in velocity). That is why the engine air intake has those boxes hanging on it (they are designed to dampen resonance pulses so the MAF readings do not become unreliable).

First of all, you are assuming the primary purpose of the resonance damper cannisters is to dampen sound. The real reason for them is to reduce resonance waves that cause MAF readings to become innacurate.

Certainly modifying the intake tract can produce peak HP gains and, when done properly, can maintain or improve the torque curve. But you have to be careful who you listen when modifying modern fuel injection systems because most of the data that is available is generated by those with a vested interest in selling products to consumers who would like more power and the FI is more sophisticated than most of them will admit. They would like you to believe the engine is delivered in a strangled state that is begging for some seat of the pants improvements. However, most tuners with real credentials will tell you the truth, it hard to improve upon the stock characteristics of modern fuel injected engines simply by improving the flow a little here, reducing a little turbulence there, especially not without changing the EEC and making other changes to the injection strategy. These aftermarket performance suppliers do not have the resources to model and measure the resonance of various intake designs so, inevitably the results are a compromise.

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Well, during lunch I returned the vehicle to stock and took the stock stuff back off and put the custom intake back on......only to have a much lesser, but still there resonance. So what does that mean.....I am done with this, I am putting the stock stuff back on and will wait for a custom tune. Too bad though, it sounds so cool under WOT.

I am waiting for a custom tune not soley becauase of the resonanance but I don't care for shifting under light load.

 

I said independent tests for a reason, there are countless independent comparisons of aftermarket intakes vs stock systems, and the aftermarket platforms produce gains, see the myriad of links posted below.

You can quote all the flow properties you like, but it doesn't change the fact that manufacturers compromise performance for a more streetable sound. The average car buyer would not be pleased if their engine had a drone or otherwise loud sound to it. In my opinion you're trying to over complicate an otherwise simple notion, and there is a reason intake packages when accompanied by a tune are some of the best bang for your buck mods. Even without a tune, the performance increase is there.

But don't take my word for it, listen to all the people with real numbers instead of textbook scenarios

http://www.eurotuner.com/techarticle...son/index.html

http://www.mustang50magazine.com/tec...ck_airbox.html

http://www.mustang50magazine.com/tec...ake/index.html

http://www.bimmerfest.com/forums/showthread.php?t=19004

http://forums.vwvortex.com/zerothread?id=4149638

 

Independent? LOL! All the links you provided take me to sites whose main source of funding $$ is advertising and/or selling aftermarket and performance parts for car enthusiasts. In otherwords, without a market for these aftermarket parts, those very sites and magazines probably wouldn't even exist! How can you call that independent? I wasn't born yesterday.

While it's true that modern engines are engineered and packaged to provide a certain level of quietness, it is not true that this engineering robs much power. A bigger engineering consideration is providing a powerband that works well in the real world because that's what most drivers want.

Yes, there are often claims of how much peak hp is gained or the company may even publish a dyno chart purporting to accurately represent the achieved gains. But companies cheat on their taxes and they also cheat on their dyno charts, sometimes in obvious ways and sometimes it's not even cheating, just a poor choice of methodology that results in bad numbers.

For example, the dyno charts that purport to show the gains from a cold air intake are done on a stationary dyno. Even if the dyno is equipped with a cooling fan in front, the fans create only a small fraction of the flow that would occur if the car was actually driving. The tester may even decide to leave the fans off for the dyno run. In either case the stock engine may be pulling the hotter, less dense air from the engine bay while, in real driving conditions, it may be getting a stream of air just as cool as that provided by the cold air intake. In my opinion, our F-150's already have a good cold air intake at road speeds high enough that the extra power might come in handy. Don't make the mistake of believing that a dyno run is an accurate representation of the kind of gains you can expect from an ambient cold air intake mod because a dyno cannot model the actual air-flow during driving conditions. This type of innaccuracy does not result from cheating but is just a limitation of the test equipment and the techniques used to obtain the figures.


Many aftermarket mods cost hundreds of dollars and provide a small gain on the peak HP while costing just as much loss in the part of the powerband that is most important to drivers on the street. The design of the air intakes on our trucks has more to do with creating the most suitable powerband for the intended purpose than it has to do with muffling the sound (although acoustics are taken into consideration as well). Some of the links you provided provide peak HP gains without mentioning what it does to other parts of the powerband or what it does to the efficiency of the engine at cruising RPM's.

OK, let's do that:

http://www.mustang50magazine.com/tec...ck_airbox.html

Here is a quote from the article you linked to detailing the tests mustang50magazine.com did on 11 different cold air intake kits for the '05 Mustang GT:

"With a huge--andstraight--4-inch inlet, a large mass air adapter, a big conical filter,and a simple shield, the JLT cold-air means business. It recorded the highest power and torque gains, but be aware--the difference is well within our defined 5-rwhp margin of error."

Did you catch that? The best improvement of all 11 CAI kits was well within their own margin of error! Hello! These kits cost hundreds of dollars and the BEST result was within their own margin of error? Further, they ended the article with this list of disclaimers:

"We can't comment on how the cold-airs affect the driveability of the car. This would have been especially interesting on the kits that specify "no tune" because of the finicky reputation the '05 computer has garnered. That test will have to wait, or you can check the Internet message boards for feedback on your cold-air of interest. Also keep in mind, we're reporting wheel horsepower, not quarter-mile times as in the good old days of 1995 Check with regular '05 Mustang racers to see what they believe are the best kits for maximum acceleration."

Did you catch that? After dyno testing 11 CAI kits they are encouraging you to check with internet message boards! Can you read between the lines? Yes, they want to help sell kits, that's where their advertising dollars come from. But no, they flat out state that they cannot tell you how these kits affect the drivability of the car in the real world or whether the mods will make your car faster in the 1/4 mile (remember they are only reporting dyno numbers). Just like I was saying above.

Then this disclaimer:

"And, remember--with most of these kits, additional tuning to your Mustang will be necessary before you can enjoy the added benefits of a larger volume of fresh air."

O.K., that's what I was saying in an earlier post and is what was my main point. The fuel injection system does not adequately compensate for this type of modification. Not any yahoo can go bolt something on or cut something off and end up with more real performance. It DOES get complicated and I am not the one making it complicated. It's just the nature of a highly engineered and highly refined modern FI'ed engine. Mess with them at your own risk. Most amatuers end up screwing up a good thing (in the worst case) or spending a lot of money for marginal gains (in the best case). Usually it is some combination of the two which is not demonstratably better than the original setup.

If messing with engines is your hobby and you enjoy it, go for it. I'm not trying to dissuade anyone. But it should be done with realistic expectations of the potential benefits and costs and you will not often get that from listening to publications that are funded by the profits/advertising of aftermarket performance kits. Even the recommendations from other enthusiasts are often inadvertantly biased. I know for a fact that a louder exhaust pipe will have 9 out of 10 motorcyclists adamently declaring the bike has more "get up and go" even when the dyno shows the exact opposite. That doesn't means gains are not possible with the proper mods, just that all too often the money spent does not translate to real gains.

 

So, what you're saying then is that a car enthusiast site (such as f150online.com) isn't the proper venue for such a test because they have some affiliation. Well that sucks, I guess we'll have to hit up Martha Stewart and see if she will do the test.

If you're going to type up all that then you might as well have taken the time to actually click the links, each was done independently, some even by guys like you and I for the benefit of the community. Surely, they cant be a part of the cai conspiracy as well right?

And yes, some only show peak, but others show the full graph (joe schmoe in his local dyno, not the manufacturer) and you see gains across the board. I could link you again, but I'll trust that you'll actually look this time.



And your four paragraphs of picking apart the independent tests is just getting ridiculous. I could argue semantics as well, but its really straying from the point, which is that they do show gains. Every test, they showed gains. shi- that must mean something right? Or no, its all chance and luck that the margin of error skewed towards improvements every time.

Yes, they encouraged you to check out real peoples experiences with them... thats a bad thing? They can't comment on drivability because its a dyno test.... They presented exactly what we all want to see. Hard numbers (where are yours btw?)

And I agree, a tune makes it much better, but to argue that there is no gain, when all the tests on modern fi vehicles show real gains is misleading and wrong. They do show gains, and 300 dollars for 10 horsepower isn't a lot of money for a marginal gain, how would you better spend that money to improve power? Get a good tune for the extra cash and you could see even more; again, how would you better spend it to increase power?


AND finally, you again repeat that they are biased, click the links bro, its real people like you and I, with real dyno charts, before and after. The only bias here is you trying to prove your point. Louder exhaust on any vehicle doesn't always mean increased performance for reasons associated with exhaust. Not intakes. If you wanted a fruit salad here (apples and oranges), I would have quoted Vince Vaughn. Hes a funny guy.

 

I think I might have to do this mod. I too like the sound of a V8 and don't need all those dampening boxes.

 

You obviously don't understand the limitations of a stationary dyno when used to measure potential gains from a cold air intake mod. I explained it in my last post. My 2010 F-150 came from the factory with a cold air intake but that doesn't stop the aftermarket suppliers from marketing one anyway.

You also appear to have missed my main point.

In any case, I really don't think I could feel 5 or 10 more HP in an F-150 that already weighs almost 3 tons. Now on my sub 500 lb. motorcycle I can feel gains as small as 3 or 4 HP so I would rather spend my money there.

 

Ah, because its so obvious you can just spout off your opinion and consider it a valid argument.

Considering your point that the sound deadening baffles are used to increase performance, yea I'd have to say I missed it.

And in said case, that same intake good for 10 hp mixed with a good tune would be quite noticeable, not to mention sound quite a bit better as well.

But your opinion is yours and my dyno charts are mine, so to each their own

 

conspiracy theories aside, I would just like to say that my dad can beat up your dad :P

 

I consider it a valid argument and you have provided no counter-point to it.

I assume you are talking about the resonance baffles attached to the air intake between the filter and throttle body, If so, I didn't say they were there to increase performance but rather to deaden resonance waves (air changing velocity rapidly) which affects the ability of the MAF (Mass Air Flow sensor) to accurately measure the mass of the air charge. This sensor is in the same tube and it's very important for it to be free from resonance waves or it will return innaccurate results. So, in a sense you could say the baffles are there "to increase performance" but it's primary purpose is to keep the intake free from the undesirable effects of resonance.

Are you saying this type of sensor does not become innaccurate in the presense of resonance waves?

 

I used to have an Airaid CAI on my old 04 FX4 5.4, and it had the same annoying resonating under those same conditions you describe. So I took it off and sold it. I didn't really feel any major gains or see mpg gains either with it.

 

Its like you're arguing with yourself. I provided multiple counter points, primarily in the pretty pictures with colorful lines that have big numbers next to them. I'm still waiting on you to provide the dyno chart that shows a cai and tune decrease performance or is a waste of money.

And I'll again reiterate, you have your opinion, by all means- stick to it. But until you actually provide some real numbers, or any other form of real data, thats all it is. Your opinion. Just don't go spouting that opinion off like it's all facts when you could negatively influence others by it.

 

You mean the dyno charts? LOL!

I already explained why I don't think a dyno is a good way to measure the impact of a cold air intake. That claim is exactly what you failed to provide ANY counterpoint to. Now you have the ***** to pretend the dyno charts WERE your primary counterpoint to that claim?

It looks like I am debating myself because I am obviously not interacting with someone logical! Thank-you for pointing that out.

 

Its cute that you're turning to trying to attack me instead of my point, that works too though. Your opinion trumps the hard numbers that independent sources provide, awful pretentious aren't we?

This is getting childish, if you really feel the need to continue, pm me, before this gets any more derogatory and embarrassing on your part. I don't mind humoring your conspiracy theories and banter about sound deadening making vehicles faster.

 

Yes most of the CAI's are over-priced ricer type show parts. I removed my air intake hose, built a 1960's style hemi ram air component to fit in place of the hose connection point on the oem plastic intake box- works excellent- even the Ford Master Mechs at the dealer came out to ask me where I bought it- they were impressed as well.

I posted a pic in the air intake section

If you do an online search for “air filter test” there is a lot of very good information. IMHO, the CAI units are NOT WORTH THE $$! Unless you are talking about a system that was specifically designed for a specific application there are very little hp/tq gains actually achieved in a street use vehicle and there are very few docs that these mfg’s can produce that actually show an increase in hp/tq in the power-band range of a relatively stock street vehicle.

I would avoid oil impregnated filters. While they have their purpose in off-road applications, Ford/GM/Dodge all have “watch-out” bulletins where the oil has contaminated intake sensors. - they even have a training video for the tech's on this (flatratetech.com) .

If you look at the flow data, WIX HP filters flow 98+% of K&N and have a much smoother flow post filter plus excellent filtering, for a fraction of the price! The OE’s have an excellent air intake system the only issue that really exists is the plastic intake tube with it’s noise canceling design- that does reduce the intake efficiency a little but makes it very quiet!. You can use a WIX OEM HP replacement filter in the OEM plastic manifold box and either remove the plastic tube and replace it with a piece of pipe/hose, etc or remove the tube completely and replace the tube by building an air ram type intake into the air box manifold (where the pipe use to attach)- make sure ti terminates above the fan shroud to avoid water intake or fan induced pulsations.