K&N filter

[JDC]

Anyone put one a K-N filter on your 4.6 and if so, what mileage changes did you note?

tks

 

[PAGeni1344]

I put one in.. dont see much of a change. I buy one bc its alot cheaper than replacing every other oil change. I get approx 29mpg hw/ 24 city (I also have new exhaust)

 

[yuhaze]

I installed one, too, pretty much for the same reason PAG* did.
I also installed an aftermarket cat-back exhaust (borla).
I believe that these are the first steps to performance improvement: let the beast breathe better!
In a short conversation with the designer at Borla, he indicated that simply replacing the air filter with a K&N will make enough difference for the exhaust to have subtle changes in its characteristics.
Having said that, even a pro in performance agrees that the K&N not only saves in the pocketbook, but also helps with performance.

 

[DubaiRich]

How much does the filter cost, san oiling kit??

 

[yuhaze]

right around $50

 

[nearwater]

So, at what cost do those 'performance filters' provide better results?
Nothing is better in every way, there must be something it's compromising in order to yield better air flow.
Not as good air filtration maybe?

I believe that the OEM air filter has been designed to its ideal purpose, strategically positioned between practicality and performance. (My friend works for the company that supplies filter/box for Hyundai, including the Genesis)
Also, with modern ECUs, no matter how much air you shove in, and how nonrestrictive the exhaust may be, the ECU will adjust according to those variables and dial back to its pre-configured output.. is what I believe.

I could be wrong, but I just don't believe in those performance 'mods' anymore.
I used to do all kinds of modification back when I was into imports, but nothing(except FI and/or tune) made significant difference other than some change in noise.
No offense to anyone who chose to use different parts for their cars. Just my $0.02

Dan

 

[yuhaze]

I tend to agree with you, but as soon as mods for ECU and TCU come out, you'll need the extra breathing capability.
I am by no means an expert. I would call myself a beginner at the car stuff. I've been riding bikes all my life and this is the FIRST new car that I purchased.
I have a mechanic friend from whom I've been getting advice, then follow up with a little online research.
I do know that some on this board - those who've had some mods longer than I - have already noticed and recorded performance and/or mileage improvements.

 

[JDC]

So, at what cost do those 'performance filters' provide better results?
Nothing is better in every way, there must be something it's compromising in order to yield better air flow.
Not as good air filtration maybe?

I believe that the OEM air filter has been designed to its ideal purpose, strategically positioned between practicality and performance. (My friend works for the company that supplies filter/box for Hyundai, including the Genesis)
Also, with modern ECUs, no matter how much air you shove in, and how nonrestrictive the exhaust may be, the ECU will adjust according to those variables and dial back to its pre-configured output.. is what I believe.

I could be wrong, but I just don't believe in those performance 'mods' anymore.
I used to do all kinds of modification back when I was into imports, but nothing(except FI and/or tune) made significant difference other than some change in noise.
No offense to anyone who chose to use different parts for their cars. Just my $0.02

Dan

Generally with any free flow filter air filter you will normally increase CFM air flow through the engine, particularly with an after market free-flow exhaust setup. The benefit is generally more HP/TQ, since you are coming closer the the max CFM the motor can flow, at the cost of a bit less clean air and a little less MPG, unless you have a fuel management setup you can tweak a bit. Most motors, off the floor, do not flow their max CFM at the top of their RPM range.

There are times when you make such a change that the on-board, OEM fuel management system is unable to adjust itself sufficiently to the new air flow rate, particularly at WOT or near WOT, so the HP/TQ gains are not realized, and in fact you may have some HP/TQ loss - until you can AFR 'tune' the car, since the optimized AFR is off a bit. When able, I normally adjust my AFR to best TTD, not max HP/TQ, though that may be a ver close AFT setting, and then set the cruise AFR to something more lean, to get back or even increase the average highway MPG.

On a recent trip I started out with a new air filter. A good number of miles were put on that trip where we were in the trail of vehicles on a very dusty fire-trail mountain road for some hours, right colse to a several car lenghts from each other, visibility terrible and speed at about a slow run - 1015 MPH or so.

Normally, on older cars with a screw on air filter setup would have become impacted with dust. After we returned to hard pack I pulled over. Dust was in and covering every milimeter of the car, door cracks, etc. The Genesis kept all of that out of the passanger and trunk compartment. The engine bay was loaded with dust as well, however, the air filter looked brand new. I later drove it to a dealership and changed it anyway. Not a bit of difference in MPG, suggesting that the intake setup on the Genesis did an excellent job of isolating the intake air charge. Unless an after market setup uses the same protected trajectory of the intake charge, where it leaves the air filter unopen/unexposed in the engine bay, that would have been a clogged air filter comming off that road.

K-N filters and the like, oiled up will remove most of that, particularly once they start to become loaded. But they will, as you offer, pass some of that through as well. That road was not the normal driving condition, though. Additionally, as the filters are mounted a bit of distance above the highway, that height above the pavement also protects the filter, overall, from road particulate.

If I could knowingly increase the air flow by air filter change alone, without a hit to mpg and know that the air flow change would affirmatively add a better TTD (not HP/TQ), I'd do it. The problem is that unless you have the equip to test out the change, you'll never really know, and the butt dyno for most folks is fools gold. I've proven that by doing over 350 dyno tunes testing out exhaust, filter and other engine mods while on the dyno. You never know the direction your AFR will move the 'performance' unless you can check it properly. Though increasing the engines CFM is the best method for more power, unless the fuel management setup brings the AFR back to specs automatically (for better MPG), or you tune for best TTD or for best HP/TQ, that new untuned AFR may just not be your buddy.

 

[yuhaze]

Generally with any free flow filter air filter you will normally increase CFM air flow through the engine, particularly with an after market free-flow exhaust setup. The benefit is generally more HP/TQ, since you are coming closer the the max CFM the motor can flow, at the cost of a bit less clean air and a little less MPG, unless you have a fuel management setup you can tweak a bit. Most motors, off the floor, do not flow their max CFM at the top of their RPM range.

There are times when you make such a change that the on-board, OEM fuel management system is unable to adjust itself sufficiently to the new air flow rate, particularly at WOT or near WOT, so the HP/TQ gains are not realized, and in fact you may have some HP/TQ loss - until you can AFR 'tune' the car, since the optimized AFR is off a bit. When able, I normally adjust my AFR to best TTD, not max HP/TQ, though that may be a ver close AFT setting, and then set the cruise AFR to something more lean, to get back or even increase the average highway MPG.

WOW! Thanks for the explanation!
My head is still spinning from all those acronyms.
The ones I am familiar with are
CFM = cubic feet/min
HP = horsepower
TQ = torque
WOT = wide open throttle
MPG = miles/gallon
could you please help with the rest?

It sounds like there is possibly something I can do to optimize my current config? I'd like to better understand that process as well.

 

[JDC]

AFR - Air Fuel Ratio, managed by the vehicles ECU/fuel management computer.

TTD - Time To Distance

When dyno'ing almost all tuners 'tune' a car to a specific air fuel ratio, like 14.7:1, or 13.1:1, what-ever their training told them to do. On motorcycles and DynoJet setups, that is 13.1:1 normally, and they generally do not tune away from that 13.1:1 goal unless they are instructed, and some will 'fight' you to do it. Those types of tunes are normally for best HP/TQ from a tune.

You can also dyno tune for best TTD, as in the 1/4 mile, which is what most folks are really after, fastest tune, and that normally will be, or will be close to the AFR which is best for max HP/TQ, as well, but not always, so the tuneer will need to search up and down a to confirm best TTD tune, the same as they do for best HP/TQ. I have seen were a .1 change in AFR has added or dropped about 10 HP on a bike. Best AFR can be touchy and will change also because of atmospheric/weather changes or changes in sea level differences/air pressure.

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[scottdk]

So, at what cost do those 'performance filters' provide better results?
Nothing is better in every way, there must be something it's compromising in order to yield better air flow.
Not as good air filtration maybe?

I believe that the OEM air filter has been designed to its ideal purpose, strategically positioned between practicality and performance. (My friend works for the company that supplies filter/box for Hyundai, including the Genesis)
Also, with modern ECUs, no matter how much air you shove in, and how nonrestrictive the exhaust may be, the ECU will adjust according to those variables and dial back to its pre-configured output.. is what I believe.

I could be wrong, but I just don't believe in those performance 'mods' anymore.
I used to do all kinds of modification back when I was into imports, but nothing(except FI and/or tune) made significant difference other than some change in noise.
No offense to anyone who chose to use different parts for their cars. Just my $0.02

Dan

You've nailed it on the nuts Dan. I completely agree with you.

 

[nearwater]

Some good discussion here.
Thanks for the detailed explanation, JDC.

So would you agree that without a proper tune, just adding a high flow filter/exhaust wouldn't do much good in terms of performance increase, other than providing more or sportier engine/exhaust sound?

Dan

 

[JDC]

Some good discussion here.
Thanks for the detailed explanation, JDC.

So would you agree that without a proper tune, just adding a high flow filter/exhaust wouldn't do much good in terms of performance increase, other than providing more or sportier engine/exhaust sound?

Dan

If the CFM increase is handled ok by the OEM ECU, you may find some increase - but not the best increase. You may even lose power. Particularly since the OEM ECU may not be mapped for best performance to begin with, and not knowing the OEM AFR, then leaning the setup with a high flow filter/exhaust, you may go a bit too lean for best performance and lose power. Conversly, if the AFR was a bit rich, you might go leaner and come closer to being spot on. You just don't know. I feel the assured method is to hit the dyno and map it the way you want it.

Yes, overall I agree what the performance added by a high flow filter/exhaust are not going to hit the numbers advertised by the manufacturers, unless you have a tune. That's been my experience, anyway. I've seen folks say they got from 5-25 HP more after such mods, and when I drove their vehidles they felt "flat" to me. On the dyno those vehicles had actually lost power, until they were tuned. Again, you just never know. On some of the vehicles the intake was completely removed, sans filter, free flow exhaust, and the engine was flowing as much CFM as the engine could possibly process. The OEM ECU's were not made for those changed parameters, and again power was lost. Many OEM ECU's seem to have a very narrow programmed set of ECU parameters. A few of them sounded like NASCar racers and that they could tear up the pavement. That seemed more a result of the mean 'sound' over real life physics/good tuning.

Some time I met Mario Andretti and wife at a party of theirs, and on several occasions following. He confirmed the same thing to me, as well as the about uselessness of air foils on passanger cars that travel under 100 MPH, or so. His experience was that air foils just start to become effective, or have a positive effect if engineered correctly, at about 100 MPH, and incrementally up.

 

[nearwater]

If the CFM increase is handled ok by the OEM ECU, you may find some increase - but not the best increase. You may even lose power. Particularly since the OEM ECU may not be mapped for best performance to begin with, and not knowing the OEM AFR, then leaning the setup with a high flow filter/exhaust, you may go a bit too lean for best performance and lose power. Conversly, if the AFR was a bit rich, you might go leaner and come closer to being spot on. You just don't know. I feel the assured method is to hit the dyno and map it the way you want it.

Yes, overall I agree what the performance added by a high flow filter/exhaust are not going to hit the numbers advertised by the manufacturers, unless you have a tune. That's been my experience, anyway. I've seen folks say they got from 5-25 HP more after such mods, and when I drove their vehidles they felt "flat" to me. On the dyno those vehicles had actually lost power, until they were tuned. Again, you just never know. On some of the vehicles the intake was completely removed, sans filter, free flow exhaust, and the engine was flowing as much CFM as the engine could possibly process. The OEM ECU's were not made for those changed parameters, and again power was lost. Many OEM ECU's seem to have a very narrow programmed set of ECU parameters. A few of them sounded like NASCar racers and that they could tear up the pavement. That seemed more a result of the mean 'sound' over real life physics/good tuning.

Some time I met Mario Andretti and wife at a party of theirs, and on several occasions following. He confirmed the same thing to me, as well as the about uselessness of air foils on passanger cars that travel under 100 MPH, or so. His experience was that air foils just start to become effective, or have a positive effect if engineered correctly, at about 100 MPH, and incrementally up.

Thanks again for the in-depth information and sharing your experience with us.
I was informed the same as your opinion.

Dan

 

[Rey]

Any modern fuel injected vehicle will run a constant air/fuel ratio of 14.7:1. This ratio has been determined to be the best for emissions. You could get better mileage with a leaner mixture and better power with a richer mixture. 13:1 is usually considered to be optimum for maximum power.
Your car runs this 14.7 ratio while it is in a closed-loop mode. In this mode the oxygen sensors signal if there is any variance and the fuel injection system corrects itself to maintain the 14.7 ratio. The addition of a K&N and most aftermarket exhausts do allow more air to flow more easily tending to lean the mixture. The closed loop system will adjust to maintain the 14.7 ratio. There is a limit to its ability to adjust but the addition of a K&N no where near approaches that limit.
Now when you need lots of power, like full throttle, the motor goes to open loop where the oxygen sensor are ignored and fuel is dumped in. Manufacturers have universally set the open loop mixture overly rich, like in the area of 10:1. So when you add a K&N, exhaust etc. you are leaning the mixture on open loop and adding more power in this mode.
A K&N alone will not make serious horsepower, but that is not to say that the effect of cumulative derestrictions of intake and exhaust will not be felt. The Genesis V8 is very restricted in stock form.

 

[STREETS]

If changing your dirty air filter to improve gas mileage has been proven mainly false, then how is spending $50 for a K&N filter supposed to improve performance when it is the ECM that controls how the engine breathes?

 

[JDC]

If changing your dirty air filter to improve gas mileage has been proven mainly false, then how is spending $50 for a K&N filter supposed to improve performance when it is the ECM that controls how the engine breathes?

The ECU does not really control how the engine breathes, but it does, in part, control the addition or substraction of fuel to the air that is incoming, and it will attempt to maintain a specific AFR, as another poster suggested, say 14.7. The ECU can or may not always be able to maintain the OEM AFR, depending on if the new intake charge is within the ECU's parameters.

The idea behind changing to a less restrictive air filter is to help flow more air into the engine - make it easier for the engine to breathe. Basic engine math is power is equal to the amount of air and fuel an engine can process. Adding a free flow exhaust at the end of the car modification, to help with a more unrestricted air charge at the front - free flow filter, is the common method when you want increased power, free- flow both ends. The theory, and usually some reality, is that de-restricting, or adding more air/fuel to the engines ability, does typically increase (some of) the power.

I have been caveating the above idea by virtue that unless you hit the dyno and verify it, or tune for the increased CFM, indeed, you might not see much, or any gain, and can, in some circumstances, lose power.

But, if you know the vehicle, and others have done the exact same mod, let's say, and they proved out that their mod made "X" more power, verified on a dyno with out a tune, and having done a baseline first, then it is almost 100 percent certain that when you do that very same mod, to your car (being the exact same car model) will have the about exact same HP gain/loss effect. The same goes for mapping it, you will have almost the exact same power, as well.

Most same model/year vehicles I've seen on the dyno all test out within very close HP/TQ tolerances from one another - using the same dyno. Use a different dyno and you will likely get very different results. I do note that certified Dyno-Jet setups that I have used have been very close to each other in their measurements. Comparing a Dyno-Jet setup, to say Thunders' dyno in AZ, Thunders' dyno reports the same vehicles with about 20-24 more HP than on the DJ setup.

If you do a mod to your vehicle try and always use the same dyno for pre-mod baseline runs, and then any future mods, else your cross results by using several dynos (excluding perhaps certified setups - e.g. Dyno-Jet) will be about useless, and maybe even confusing. Comparing your dyno results for a car, to someone else's off a different dyno is about equally useless - unless you all use the same dyno, and hopefully on the same day-n-time.

For me the idea of a K-N for the 4.6 seems a good idea, and with a quiet free flow exhaust, but only when I can get into the ECU and modify the AFR to my liking. Else you are likely to have a bit worse MPG, as even if the ECU could maintain a set AFR with the new air charge, say 14.7, or what-ever, the car is passing more air with the related more fuel... = a little bit poorer MPG. If the power gains (loss?) are negligible then the MPG change will be about negligible, as well.

With a dyno then I could go for highest HP or best TTD, and at the same time, do a cruise RPM mapping as well, because normally if you dyno tune to the fastest TTD or best HP, you are going to map the entire fuel map to the same AFR, including your cruise range. Dyno-Jet systems, many anyway, auto tune to a specific AFR, but you can go back into the map and change any TP/RPM range you wish.

On a turbo bike of mine, before turbo the MPG was about 40-42 highway at 70 mph, OEM AFR. After the turbo and a 'turbo' tune on a Dyno-Jet setup, to 12.5 AFR, the MPG went to 26-27 highway. Shortly after that I did my own tune for the bike, changed the AFR in all cells to 13.1, excluding under boost, which I kept at 12.5, and at cruise range to 14.2 (TP/RPM) and the MPG went back to 38-40. I could increase the MPG a bit more if I went higher than 14.2 for the cruise range. I haven't taken the time to check out what the results of that type of change would bring.

I'm looking for an piggyback ECU for the 4.6 at this point. Once I find one, and the software to map the car, I will make some mods. I spoke to Rhys and they used a modified AEM piggyback ECU for their Genesis 4.6 engine project. I was told that just to do the rewiring engineering to get the AEM unit to work with the Genesis system, it cost them 25K, and it was fairly complete/done, but not totally complete.

 

[yuhaze]

Thank you JDC!
This is very refreshing!
You have characterized these computer controlled beasts really well!
I now realize that visiting a shop with a dyno is imperative, to get the best out of these mods.
I will start looking for a reputable one in my area and begin my quest for optimized AFR for WOT and cruising speeds.
I remain concerned at what happens when I visit the dealer; will a tuning from the dyno shop be erased if the dealer performs some sort of maintenance on the ECU/TCU?

 

[JDC]

Thank you JDC!
This is very refreshing!
You have characterized these computer controlled beasts really well!
I now realize that visiting a shop with a dyno is imperative, to get the best out of these mods.
I will start looking for a reputable one in my area and begin my quest for optimized AFR for WOT and cruising speeds.
I remain concerned at what happens when I visit the dealer; will a tuning from the dyno shop be erased if the dealer performs some sort of maintenance on the ECU/TCU?

Probably, if you had your OEM ECU re-flashed. You could tell the dealer to not touch the ECU, as in leave the map alone.

At one dealership I went to, for a non-ECU/non-engine/non-electrical issue repair, the tech looked at the map. He discovered it was custom and wrote over it, but he saved it to the dealership computer. I told him it was illegal to copy custom software, my map, without my permission. The service manager came in and said there was nothing he could do, and would not give me back a copy of my original custom map (I did have one at the house and another copy loaded in the secondary map location of the ECU).

I advised him to stay put, and went to the dealership manager, and briefly explained the details of his service department 1: writting over a custom map without my consent while they were only authorized to work on a completely seperatge issue and 2: stealing my map and putting in on their computer, and lastly, to give me back that map - erasing it from their PC, or the local judge would fine and order them to do so.

He was a retired attorney and understood what poor legal and customer service sense and poor decision the service department had made. He had the map back in my hands within 5 minutes.

The probability of the dealership erasing your map, if they come to discover a custom map on your OEM system, seems likely, and perhaps it may end up - in the long run, if you have any engine issues later, voiding the engine warranty, as the ECU is central to the functioning of the engine. It is unlike almost any other part of the car, and modifying that changes many aspects of how the engine should - OEM wise - run, per the manufacturer.

But, on a piggyback system, which is more likely what you will have, unless re-flashes come about for your Genesis, your OEM ECU map would not be touched, as the piggy-back system has it's own map that over-rides a portion of the OEM ECU functioning.

That is one reason to have the new ECU/piggyback with software, so you can always reload/modify the map yourself. At the dyno, make sure you tell them you want a copy of all of your run files and a copy of the resulting map, on a zip drive.. to take home.

If they say nope, they don't go there, go somewhere else. I initially found several that said no. I talked to the managers and they relented. My favorite place I stayed in the booth during the tuning, providing feedback of how I wanted the AFR changed in the ranges, as well as after the map was done, to 'test' the results and visually ensure by shifting the AFR out of range, incrementally, to make sure it was spot on, myself. I've seen a number of tuners just tune to their trained "AFR", and call it good.

I must have 600-700+ run files by now. I was so anal about it I made a spread sheet, with the various parameters of the modification, percent/# of change (+/-) with TTD, HP,TQ, etc. By the time I was done testing intakes, modified air/boxes/intakes and modified exhausts, I had learned quite a bit of what intake mod would create how much power/TTD with what exhaust. It was great learning.

If your software has the ability to load the run files, it is great for comparison of each and every mod you make and your understanding of how those mods truely effect the cars performance.

 

[scottdk]

Ah, this reminds me back in the day when I had a Stage 2 Jet Chip in my DOHC Grand Prix.

My how times have changed.....for the better