Derestricting Intake Air Flow

[Rey]

Like many others I have removed the air flap in the airbox. In my opinion, this is designed as a secondary air source. The primary source is over the top of the radiator. This source draws intake air upwards from behind the grill. Note, the two air ducts on either side of the hood latch (body side). These air ducts have a grid, which in my opinion serves little function except mabe to attenuate intake air sound. The grid takes less than five minutes to remove with a hacksaw blade.
Also removed the secondary air filter located in the top of the airbox. My BMW Z4 has a similar design, which I also removed. Not sure if this secondary filter is for sound attenuation as in the BMW they take certain steps to increase intake sound. Perhaps these mfgs do not have confidence in their filter elements.
I installed a K&N. A few words on K&N; I am a geezer and was one of the first users of K&N filters several decades ago. This was when we had to oil the filters ourselves. Perhaps it was with this self-oiling that "over-oiling" rumor occurred which caused oil vapors to collect on MAF wires. Whatever, all K&Ns now come preoiled from the factory; and I feel absolutely assured that there is no chance whatsoever of filter oil from a factory-oiled K&N contaminating a fuel injection system. That's my view.
Took a look at the MAF screen. I do not believe it has a filter function. Intake air is sufficiently filter by the air filter, so the screen is a redundancy. But, I wonder if the screen serves to "straighten" airflow across the MAF wires? The screen is far "thicker" than an ordinary window screen. In the past I have removed such screens on GM autos, but I wonder if by doing so I caused the MAF to constantly vary settings with a more turbulent airflow. I say this because I observed a constantly-varying mpg reading on a scanguage with my GM auto while traveling on an absolutely flat highway in cruise control with dead air (no wind). Comment? Anyone removed their MAF air screen?

 

[STREETS]

Seems like a lot of work, re-work to the stock air intake. I am sure Hyundai would classify such modifications as warranty VOID. I am from the school, if Hyundai wanted unrestricted air flow that bests performance & economy they would have. No matter how much air you let in, the computer controls what the engine receives.

 

[ctrcbob]

Like many others I have removed the air flap in the airbox. In my opinion, this is designed as a secondary air source. The primary source is over the top of the radiator. This source draws intake air upwards from behind the grill. Note, the two air ducts on either side of the hood latch (body side). These air ducts have a grid, which in my opinion serves little function except mabe to attenuate intake air sound. The grid takes less than five minutes to remove with a hacksaw blade.
Also removed the secondary air filter located in the top of the airbox. My BMW Z4 has a similar design, which I also removed. Not sure if this secondary filter is for sound attenuation as in the BMW they take certain steps to increase intake sound. Perhaps these mfgs do not have confidence in their filter elements.
I installed a K&N. A few words on K&N; I am a geezer and was one of the first users of K&N filters several decades ago. This was when we had to oil the filters ourselves. Perhaps it was with this self-oiling that "over-oiling" rumor occurred which caused oil vapors to collect on MAF wires. Whatever, all K&Ns now come preoiled from the factory; and I feel absolutely assured that there is no chance whatsoever of filter oil from a factory-oiled K&N contaminating a fuel injection system. That's my view.
Took a look at the MAF screen. I do not believe it has a filter function. Intake air is sufficiently filter by the air filter, so the screen is a redundancy. But, I wonder if the screen serves to "straighten" airflow across the MAF wires? The screen is far "thicker" than an ordinary window screen. In the past I have removed such screens on GM autos, but I wonder if by doing so I caused the MAF to constantly vary settings with a more turbulent airflow. I say this because I observed a constantly-varying mpg reading on a scanguage with my GM auto while traveling on an absolutely flat highway in cruise control with dead air (no wind). Comment? Anyone removed their MAF air screen?

What "Second Air Filter located on top of the Air Box"? There is only ONE Air Filter, and that is inside the airbox. If you replaced it with a K&N, thats ok, but that is the only air filter there.

Funny you should mention the primary source of air, over the top of the radiator. Because I think different than you, and because I wanted to protect my engine when I knew I was going to drive through dust storms while out in Arizona last Spring, I built an additional air filter, placed in front of the primary source of air, over the top of the radiator. I used the very thin foam material that you buy for home window A/C units. Oiled it and attached it in front of the air intake. This filter was thick with red dust. Saved the stock air filter after I drove through those dust storms. After I washed the red dust off the engine, and after I cleaned this "pre-filter", I re-oiled it and again placed it over the air intake above the radiator. I like it so much, I've kept it. I keep it in place by removing the little push pins and sticking the foam under the supports, so that the foam falls over the air intakes. I no longer "oil" it with filter oil. I now just spray it with WD-40. This pre-filter is far enough from the standard filter that no oil or fumes get to the standard filter, plus, even if it did, it would not get past the stock filter. Has not caused any performance problems, and my great gas milage stays the same.

If memory serves me correct, the car only has three air filters.
1. The Engine Air Filter.
2. The Cabin Air Filter
3. A Gas Tank Air Filter (its in the owners manual, but Genesis Techs have to look up the location, plus it does not look like it is easy to change, assuming dealers even have it in stock.)

 

[Rey]

Secondary air filter is located in the lid of the air box. It is of the same material as the primary filter which is located on top of the air box base. Just open your airbox and observe the air filter lying on the base of the air box. Then run your fingers underneath the lid of the airbox. You will find another filter.

It seems every time a modification of any sort whatsoever is mentioned, someone chimes in to the effect that a modification voids one's warranty. There is a law on the books which addresses this issue. I do not have the citation, but as I recall it is an act that is commonly referred to as the "Magnuson Act". The essence of this legislation is that the mfg/dealer has the burden of proof that a particular modification has a direct effect upon a failed part in order to deny a warranty. Thus, if your rings fail due to undue wear and you show up at the dealer with a K&N filter for warranty repair, the dealer may claim that the undue wear was caused by the "inept" K&N filter, and deny your claim. Now as a practical matter this burden of proof requires that you bring the action in court (you are thus the "moving party"), which is a hassle.

As for the wisdom of a mfg in designing the perfect part/system that you should never question, I disagree. I worked once in fairly high position in the auto industry and I can assure you that mfgs spend a lot of time designing the cheapest part that will do. Still, in my opinion OEM parts are usually superior to aftermarket, but there are many exceptions (i.e. shock absorbers and air filters) where an aftermarket part is superior.
Then manufacturers make continuous change to a vehicle: to wit the design changes made to the 2010 Genesis' suspension.

 

[ctrcbob]

Although I've had the lid off in the past, I never noticed a filter in there. Perhaps tomorrow, I will pull the lid off and check inside the lid, just to see what you are talking about. (While I have the lid off, I'll check the "regular" air filter).

What I want to know is; if there is in fact a secondary air filter in the lid (and I have not seen it yet), why is it NOT mentioned when the book calls for an air filter change? The only filters mentioned (that I remember) are the engine air filter, the cabin air filter, and the fuel tank air filter (what ever and where ever that is).

I'll look in there tomorrow. (Time to clean my homemade pre-filter also).

 

[STREETS]

I wasn't refering to air filters, K&N or others voiding warranty- but the the "removing grid with a hack saw blade" and reinventing duct work. Any mechanical or physical change might be a game changer.

 

[Rey]

Streets: in order for a "game change" the mfg. must demonstrate that the removed grid has directly led to the warranty claim. I cannot imagine that a minor increase in airflow will tax the reserves of the fuel system leading to a damaging lean condition.
This can get ridiculous. Say if I change the trunk emblem as many have done, does this negate my paint warranty? If you are worried about a particular change, then by all means do not do it.

 

[TJPark01]

Although I've had the lid off in the past, I never noticed a filter in there. Perhaps tomorrow, I will pull the lid off and check inside the lid, just to see what you are talking about. (While I have the lid off, I'll check the "regular" air filter).

What I want to know is; if there is in fact a secondary air filter in the lid (and I have not seen it yet), why is it NOT mentioned when the book calls for an air filter change? The only filters mentioned (that I remember) are the engine air filter, the cabin air filter, and the fuel tank air filter (what ever and where ever that is).

I'll look in there tomorrow. (Time to clean my homemade pre-filter also).

It's a foam filter housed in a plastic mesh housing located directly above the removable paper filter. It's a back up and isn't meant to be changed. You forgot fuel filter (which is in the fuel pump inside your gas tank. The Fuel tank air filter, filters fumes when you are filling up your gas tank, you never need to change that unless...and this is gross....spiders (and sometimes rodents) crawl down in there and like to build nests. They block the vent that lets the gas vapors escape when you are filling up your tank. Often you will be unable to fill the tank in one shot and will have to continuously hold the gas filler tube neck and manually fill the tank instead of just setting the nozzle on autofill.

 

[dataguy]

In short, it's probably very likely they will try to deny the warranty claim automatically in face of any evident mods because most people probably won't fight it. Taken to arbitration, the manufacturer would need to produce evidence showing the modifications caused the failure. So fighting it or taking it all the way to arbitration would probably work to your favor.

But then again, it is definitely possible to perform a modification that does cause damage, and depending on how severe the damage is, you may be on the hook for it.

 

[STREETS]

If the trunk Wing Badge replacement get rust thru around it, then I am sure the Hyundai district rep will double take at the badge and question what was done beneath and shy from warranty coverage.

______________________________

Help support this site so it can continue supporting you!

 

[ctrcbob]

Ray,

Time for me to eat "Humble Pie". I WAS WRONG.

There is a second air filter located in the lid, although not the same filter material like you said, but of foam, like TJPARK01 said. I never saw it before because I never even thought of looking up in the lid. This second air filter is made of a foam material that sure looks like it would restrict the air. Although it was not dirty, I removed it from its "cage" and washed it, then after I let it air dry, put it back in its cage, then snapped the cage into the lid. Removed the regular paper air cleaner, which is still clean, however I did see "grit" laying on the bottom of the filter housing. Well, I thought that any grit would be caught by the pre-filter that I built, placed in front of the air intake above the radiator. Then I dawned on me that the grit gets in from the Secondary Air Source, when the magnetic trap door (flap) is open. I then removed the Secondary Air Source, just as some of you said, just to see how it works, and where the Secondary Air comes from. The secondary air comes from behind the headlight whenever the engine needs more air, with the increased airflow causing the magnetic trap door to open.
Well I cleaned out the grit from the bottom of the airbox, replaced the Secondary Air Source device, replaced the Paper Air Filter, and replaced the lid.

Now I understand how it all works, and now I know that my homemade Pre-filter over the air intake above the radiator only filters air when the engine is running slow. When you tromp on it, the engine calls for more air, and the magnetic trap door opens in the secondary air source. I guess that when I drove through those three (or four) dust storms in Arizona, the engine must have been going slow enough that the Secondary Air Source Trap Door did not open, because my homemade Pre-Filter was full of RED DUST, but the paper air filter was clean.

Lastly, don't really know why they have that Foam air cleaner in the lid of the airbox. After 20k miles, it was clean, and only looks like it restricts the airflow. Yes, I left it there, completly stock, as I figure those who designed the system know what they are doing. (Thats why they get paid the big bucks and I don't <grin>) Matter of fact, I left everything completly stock.

 

[TJPark01]

I am from the school, if Hyundai wanted unrestricted air flow that bests performance & economy they would have. No matter how much air you let in, the computer controls what the engine receives.

Thank you. As much as people want to mess with the air intake, the ECU is going to control the air/fuel mixture. The only way you're gonna get more power out of this car is to change the ECU, then the air intake, headers and exhaust. You will get more power, but your fuel economy will be negatively affected, which I'm guessing people that do this don't care too much about. Messing with just the air box and all of it's components is just going to make noise.

 

[motorsportsauthority]

Thank you. As much as people want to mess with the air intake, the ECU is going to control the air/fuel mixture. The only way you're gonna get more power out of this car is to change the ECU, then the air intake, headers and exhaust. You will get more power, but your fuel economy will be negatively affected, which I'm guessing people that do this don't care too much about. Messing with just the air box and all of it's components is just going to make noise.

The key here is air/fuel mixture. It's a ratio. When the ECU senses more air, it'll dump more fuel. The ECU is allowed to adjust within a certain deviation. An intake and exhaust change will add power without an ECU change. It may not be significant, but there will be a change.

 

[ASHDUMP]

The key here is air/fuel mixture. It's a ratio. When the ECU senses more air, it'll dump more fuel. The ECU is allowed to adjust within a certain deviation. An intake and exhaust change will add power without an ECU change. It may not be significant, but there will be a change.

Will it be "change we can believe in"? jk

I'm still on the Scott Brown high here in Massachusetts!

 

[ctrcbob]

Will it be "change we can believe in"? jk

I'm still on the Scott Brown high here in Massachusetts!

Now all the women in this site want to find the old Cosmo Mag that has the nude centerfold of Scot Brown.

 

[mcginnpm]

TJPark01,

I think your argument is about 99% correct. The ECU is gonna look at data from the MAF (mass airflow sensor), the O2 sensors and other various inputs to optimize the amount of fuel injected to obtain that optimal stoichometric air/fuel ratio of 14.7-to-1.

Where I think you are off in that last 1% is that if the motor has to work harder to breath in the air it needs to obtain that 14.7-to-1 mixture, this can rob power and performance. If the Genny had to suck in the air it needed through a 1/4" straw, I'm quite certain we'd see a change in power and performance than if it was breathing through a 4" pipe. All the grids, screens, filters, intake ductwork, etc. can make it harder for the motor to breath.

Air has an inherent, albeit low viscosity. Anytime air interacts with another surface there is friction, or drag, which requires energy to overcome. That energy has to come from the fuel burned in the motor. What I wonder is just how significant the impact is? There might be a noticiable impact to top-end power output. Look at the motor of a top-fuel dragster (whose #1 concern is maximum power) and you'll see that the air intake is nothing more than a short venturi tube on top of the carburator which itself is mounted right on top of the cylinder (i.e., the shortest, straightest, cleanest path for air to get into the cylinder. But, for normal "putzing around" driving, I doubt that there is much, if any, impact to fuel economy from removing all the "obstructions".

 

[ctrcbob]

What I don't understand is why is there the additional foam filter in the housing cover?

I wish I had thought of putting the foam to my mouth to see how easy it is to breath through it (pass air). When I took and cleaned mine, I found it was already clean. Nothing gets past the stock paper air cleaner anyway. Seems to me that the foam filter causes the engine more difficulty breathing. Well, thats the way they designed it, so I assume (ass-u-me) they know what they are doing. If anyone ever removes the foam filter, let us know what happens. (More power? Better Gas Milage? etc.)

BTW, If anyone ever does remove the foam filter, no need to wash and clean it as it already is clean, plus it takes a while for it to dry. I removed mine from the plastic cage, washed it, rinsed it out, and there was NO DIRT in the thing. Then I wrapped it in a towel to remove any water, the I hung it out to dry. Takes a while to dry. I.E. I wasted my time washing it. (But why is it there?)

 

[Rey]

Logically if one wanted to use two filters the coarse filter would be first so as to catch the larger particles. Here the situation is reversed with the first filter catching all particles. So, my guess is that the secondary filter is designed for intake noise attenuation.

Perhaps Hyundai uses this secondary filter because some high-end mfgs also use it. I know that BMW used it on their '07 Z4 as I have one. I informally "tested" my BMW on a long cross country trip. Removing the filter seemed to increase mileage. It most certainly did not decrease mileage.

One way to test would be to use a "ScanGauge". Hold the car in neutral and try to maintain 2000 rpm with the ScanGauge reading "gallons per hour". My Genesis is still too new to test in this mode.

As for intake noise, I hear no difference whatsoever with a derestricted intake at normal city/highway driving. The increased noise level is only heard at wide open throttle, and even then it is subdued compared to many other cars.

The nice thing about derestricting is that it is easily reversible in about 15 minutes

 

[orthoman]

TJPark01,

I think your argument is about 99% correct. The ECU is gonna look at data from the MAF (mass airflow sensor), the O2 sensors and other various inputs to optimize the amount of fuel injected to obtain that optimal stoichometric air/fuel ratio of 14.7-to-1.

Where I think you are off in that last 1% is that if the motor has to work harder to breath in the air it needs to obtain that 14.7-to-1 mixture, this can rob power and performance. If the Genny had to suck in the air it needed through a 1/4" straw, I'm quite certain we'd see a change in power and performance than if it was breathing through a 4" pipe. All the grids, screens, filters, intake ductwork, etc. can make it harder for the motor to breath.

Air has an inherent, albeit low viscosity. Anytime air interacts with another surface there is friction, or drag, which requires energy to overcome. That energy has to come from the fuel burned in the motor. What I wonder is just how significant the impact is? There might be a noticiable impact to top-end power output. Look at the motor of a top-fuel dragster (whose #1 concern is maximum power) and you'll see that the air intake is nothing more than a short venturi tube on top of the carburator which itself is mounted right on top of the cylinder (i.e., the shortest, straightest, cleanest path for air to get into the cylinder. But, for normal "putzing around" driving, I doubt that there is much, if any, impact to fuel economy from removing all the "obstructions".

Guys,
I driven with out the restrictor unit in place for over 3,000miles, very litle change in MPG (maybe due to harder driving) its true you can gain HP by allowing more air in and there's nothing the ECU can do with the MAS to change this. The V8 sounds a little better lag is better but my Dunlaps are suffering. I recomend removing the flow controler (somewhere in this thread are pics and scematics), just make sure your filter is placed correctly and clean. Have fun

 

[MrB0462]

The key here is air/fuel mixture. It's a ratio. When the ECU senses more air, it'll dump more fuel. The ECU is allowed to adjust within a certain deviation. An intake and exhaust change will add power without an ECU change. It may not be significant, but there will be a change.

Exhaust generally in a normally aspirated car does not get you a gain in horsepower. If exhaust restricts flow it may reduce heat sink which will not increase hp but prevent the loss of hp.

Ask any Vette owner who has gone through the exhaust game - much money, no more power but a better look and sound.