No one has published any validated data from real testing of changing the 164 intake filter box design.

The routing for the stock intake is much more likely designed to take in colder air than is near the radiator, and is also designed to avoid taking in too much water from rain.

My own opinion is that there would be little or no real gain from modifying the design or adding a KN filter to this car due to the fact that the air in the engine compartment is very hot compared to many other cars. Of course, you may do whatever pleases you to change the looks of your car but I don't think you will be able to measure any changes in performance.

 

You are right about having the element in the engine compartment, especially on a 164 (hot.) A real cold air intake puts the element in an area that is not exposed to engine heat. In some cars where this area doesn't exist, a 'wall' is built to isolate the element from the engine compartment.

Regarding power gains, you might be suprised. On my 1997 BMW 540i 6-speed (just sold) I installed a Dinan CAI (cold air intake.) There was a small amount of sheet metal trimming required in the engine compartment and installation required removal of the front bumper (only two bolts on that car - amazing.) In the end, the cone filter was located right behind the fog light and picked up air from a location almost identical to the small grille (inboard of the fog light) on the 164.

Dinan had dyno results, but until I drove the car after the CAI install, I was very skeptical of their gains. I was suprised to find a VERY NOTICEABLE increase in both torque down low and pull above 3500 rpm. I was happy with the performance results and the change in intake noise was an added benefit. It sounded much more serious under full throttle, especially in the low to mid rpm range.

As long as the Bosch engine management can compensate for the added flow of air in and out (if you do exhaust mods too) by letting more fuel into the engine to keep the air/fuel mixture in check, you should be able to feel it out on the road.

More air + More fuel = more HP

 

K&N

I use to have a 164L, which I modified with a K&N cone filter, but as my mechanic warned me, there was, and is too much heat under the hood of a 164. I also talked to another 164 owner, who located the cone down low. This was great for sucking up rainwater and straining for plankton.

Presently I have a 164 S, the previous owner has drilled some one-inch holes in the front of the stock air box, (which one of my Mechanics had also suggested) I also just upgraded to a K&N panel filter, a direct replacement for stock, and have noticed some minor performance gains.

 

I would just add the K&N panel filter; the intake plenum/runners is where the most heat is getting transmitted to the intake air IMHO. The air box might get warm if sitting in traffic but there should be enough flow around/through it on the open road to keep it cool. The K&N unit helps a bit on low end torque; and improves engine's ability to breathe at high RPM's.

 

It's really the front or left side exhaust manifolding that generates most of the heat, along with the radiator. That hot air then could get sucked into the intake if the intake just ended in the compartment.

 

Yep; that's why the car has the air intake on a tube that goes down/left away from the engine heat. But this makes a big issue for water; be sure not to drive the 164 through any standing water because the air intake is about 12-14" above the ground level (anti-snorkle tube).

 

Had to drive our Milano through about 16 inches of water one time when the town I was in a motel flooded in the night in a storm. We had standing water in the footwells, had to drive in stocking feet. Luckily it was just fresh stream water and dried out ok. The 164 might have been in big trouble.

 

I've modded the stock airbox. Makes it a little more willing to rev in the top end, but the NOISE.... It draws attention from just about everyone on the street (not loud, just unusual around here for a stock-looking luxury sedan to have such a throaty intake roar )

 

I've modded the stock airbox. Makes it a little more willing to rev in the top end, but the NOISE.... It draws attention from just about everyone on the street (not loud, just unusual around here for a stock-looking luxury sedan to have such a throaty intake roar )

How did you mod the airbox? Intake noise is SWEET! And the nice thing about intake sound is its really only noticeable at moderate to full throttle, not much just cruising arouund town (compared to exhaust mods IMHO.)

 

There are no significant gains or reasons for doing this on the 164 or any car for this matter.
The stock box on most cars is highly engineered by the manufacturer to achieve a cold air intake.
Hype in the modding community has put this seed in our heads that cold air intake is better than the stock box! K&N being one of these manufacturers that claims that their filters will produce more HP gains through better flow!
They fail to mention that the filter is really a one time use filter, that the oil gets sucked into the intake and or falls to the bottom of the box with the firt it holds back, then what are you left with?? Nothing but cotton! Sucking in microparticles into your engine which mixes with the oil and reduces longevity of the engine you so proudly own and maintain!
Cold air intake is hype! A money maker!
I have tested OEM paper, K&N, and a oiless foam filter!
I find no real difference in any of them. The paper and oiless ( out of production now) were the best! I had no residue in the intake from these 2.
I suggest spending your time and money on something that actually works!

I still use a OEM paper filter and change it often! Best protection against any microparticles entering the system!
K&N is a joke! Great for race day!! But that is all. K&N is all marketing!!
There are no gains with the K&N. I think $30+ for a paper filter every 30K is not a waste of money at all! Best protection there is for your engine and the flow is not much different from K&N to tell you the truth! I use to have a research firm in nevada who did this test in their labs.
K&N had a bit better flow but way less filtering properties than paper, foam had good flow and good filtering, but paper had the best filtering with just slight less flow, not much!!!

The OEM box takes cold air from the inner fender which is just fine. I have tried ram air, NOTHING! I have tried ram air and K&N, NOTHING, I have tried it all and there is no difference from OEM box with paper filter!!
Hope that explains some things? If not I can go more into detail why it would not work?? I just did not want to bore!
I would not worry about hydro-lock with the stock box at all!

If you want to do anything, use Thermo-tec products and wrap the box/intake tube and intake hose with insulation all the way to the throttle body! This will reduce the heat from the engine penetrating the cold intake air!
But honestly, the air coming in may only change about 1-2ºF through the engine compartment! The OEM box is the best way to go!

Ciao!
Jason

I just had my airbox out as part of the clutch hose change and saw that the inlet tube on the bottom of the airbox turns outboard into the void area above the horns. I suppose this was done to minimize intake noise.

Has anyone modified the tube to draw cold air from the front of the car? It looks like a straight shot down to the small grille inboard of the foglight. That ought to be a positive pressure area, at least more positive than the stock air pickup location.

While on the subject of the airbox, just how restrictive is the factory unit? Is there any dyno data on switching to a K&N in the factory airbox? How about a full-on cold air intake with a K&N cone filter located down behind the aforementioned grille?

 

OK, now I have to chime in. A properly set up intake will improve performance. I have the dyno results to prove it. My intake system has been tested over and over for changes in air pressure, temp, on the Autobahn for top speed and of course on the dyno.

The stock intake on Alfa V6 was great in its day but advancements in filter design and materiels have made it obsolete. Go to any import drag racing event, most of the competitive cars will be using a cone style filter. Why? Because they want to win.

As for longevity, I think I have done more to prove that my stuff works over the long run then anyone else. I have said it over and over, our GTV6 has 180,000 miles on it since overhaul with our intake system. For at least half that time my house was on a dirt road! That means every time the car left the house it had to travel a mile in the dirt.

 

Would like to see the dyno tests, and pix of the setups.

I suspect many of the racers use cone filters because, well, it looks cool to them. There may be certain engines which might benefit a little from something like the K&N, as long as it doesn't draw in hot compartment air, or have too long an intake tube (I've seen these) that in fact would have long tube flow drag, actually limiting mass flow. An increase of air flow from mods or changes over the stock setup would most likely be realized only at the highest rpms, not that useful a situation for street driving.

Most engines these days will show very little wear from dust over many thousands of miles due to different filtering designs, as long as there is something to catch the birds, bees, rocks, etc. As long as you don't live in an area where there is abrasive dust such as volcano ash, like we've had here in the Northwest US at times, the modern engine should show hardly any wear compared to those of the 50's a, 60' and 70's. I have yet to see significant cylinder or ring wear in Alfa engines. It's just not a problem, even though people think they need to rering and rehone the cylinders when they rebuild the engine. Usually it is just the valves, guides and bearings. Even the main crank bearings don't wear that fast.

 

My intakes give an increase in power througout the rpm range. Of course the greatest gains are at high rpm, that's true with most mods. Our Alfa V6 intake gives honest gains of about 5 horsepower on a dead stock 2.5 and about 9 horsepower on a 3.0. The more powerfull the motor the greater the gains. Our intake for the Cobalt SS Supercharged gives a 9 horsepower increase at 6200 rpm and a peak increase of about 5 horsepower. The Cobalt was tricky to improve on because it has a cone filter located outside the engine bay from the factory. Remember these are all wheel horsepower numbers, flywheel numbers are higher..These numbers may not seem like a lot but that's about all you are going to get from any bolt on with these cars. Well, I guess I do have that other 75 horsepower bolt on....
I don't want to hijack this thread and turn it into another Greg Gordon's intakes thread. I don't make a 164 intake, my point is simply that there is room for improvement and while there are a lot of snake oil salesmen out there selling stuff that doesn't work, there is room for improvement in our cars.

 

The problem is that the 164 is kinda unique compared to a straight ahead design like the GTV or Milano. The air flow in the compartment is limited and very hot, and there is no room to do much add on wise. Fiddling with the airbox, as first suggested, just doesn't offer anything without compromising something else about the engine.

 

Good point, I am not a big fan on sidewinder engine setups. Without having the car in my shop I can't say for sure if I could improve on it or not, although I think I could.

 

I'm not a K&N fan and I also think they are way exaggerated on their performance claims. So I have never bought a K&N filter before (although a couple of my cars came with them) ... oooh well, until this morning! I am now confessing that I just ordered two 164 (non-cone) filters this morning ! It was a good deal that it was hard to pass up! $32.84 each (free shipping also ) ! Where? Amazon! But, sorry, I just checked and the price now went back to $45.53.

There are pros and cons on the various type of filters and there were plenty of debates before so I don't want to go into any detail here !

I'm just planning to use them as replacement filters (with the cleanable, re-uable feature). If they last 2 times the OE paper filters (that are at $17-$18 + shipping), then they will worth the money. I kind of doubt that they'll make any noticable difference for our normal day driving. I'll report back if they do !

Bob

 

K&N panel filter (P/N 33-2645) is $60 from Autozone and others. Why not just use the K&N filter for ~50k miles re-oil it when you do an oil change; maybe flush it out with water once every year. Toss it when it hits 50k and buy another one. This is more economical than buying paper filters; and you more than likely have a better/cleaner filter element over it's entire lifetime.

IMHO they do flow more air more efficiently than paper; this is much more noticible on cars that have a small filter panel. IIRC the 2.5 Ford V6 in the Probe-GT that I had was about 1/2 the size of the Alfa 3.0 filter. When I changed it to a K&N the performance increase was immediate and dramatic (the paper element was not very dirty prior to change either). I do think these filters are an improvement over paper; and I can't see it being better or worse than foam.

 

The problem is that the 164 is kinda unique compared to a straight ahead design like the GTV or Milano. The air flow in the compartment is limited and very hot, and there is no room to do much add on wise. Fiddling with the airbox, as first suggested, just doesn't offer anything without compromising something else about the engine.

My thoughts as well. I am not saying a properly made airbox would not gain anything or loose longevity! I am also not saying this has to do with racing either. To me the post sounded like he just wants to slap on some filter to get more HP and that is not the case with the 164 nor many other vehicles.
My point is that that cold ait intake fade has gone way out of wake with their claims! If you properly engineer a new intake, yes I can see you would get some gains from it! I sold a 3 layer oiless DTM filter that did help in the response of the engine over the paper filter. But I would say I did not gain much Hp. If you were to properly do this job on the 164 you would need a new AFM, or actually change it to the newer Mass air flow sensors insead of the restrictive AFM.Then have a pipe made to pick up air from the fender arear where you could mount the cone filter. Makes NO sense to mount a cone filter in the engine compartment where it can pick up 200ºF air over the fender where it picks up the ambient air.
After all this to pick up possibly 1-3 Hp? Or even 5 hp? Not worth it in my book. I would not want the filter down in the fender so I can get hydro-lock.
on a race car it is a different story! A different thread! Now if we are talking a daily driver and you want to spend the money and time to do this, by all means. If a race car do what you can to pick up all the air you need from where ever you need.
I have seen dyno's from these cold air intakes with the cone filters.
Not that impressive to me to go out and rip out everything.
But I have not seen the dyno's on the GTV yet so I may put my foot in my mouth! From what I have seen in the industry and from what I have tested on other cars it is not much improvement to be worth it.

I am just talking and making conversation here not trying to say your wrong greg at all. I am sure you gained soemthing from your set up on the GTV.

I would love to see the dyno charts and pictures of your set up?
What did you do? New MAF? New piping most likely? Omitted the air box?

IMO, this type of mod is not going to be effective on the 164 for reasons mentioned above and for the shear weight of the vehicle, I dont think the extra air and response from the engine would be worth it.

Curious?

Ciao!
Jason

PS K&N is a great 1 TIME USE filter. There have been many tests showing theat K&N can reduce longenvity of your engine and turbo if you have one.
As mentioned the K&N uses OIL, oil can get sucked through the intake into the engine. It has been documented to ruin AFM/MAF sensors, ruin turbo systems and wear on the engine internals.
Also once the microparticles hit the oil, it is useless, the oil filled with the dirt falls to the bottom of the air box or sticks in the filter reducing air flow.

The oil that has dried (sucked in the intake) and the dirt filled oil stuck in the filter or on the bottom of the box now reduces it's filtering capabilities!

You can take out a filter after a week of driving put it up to a light and see where there is no more oil protecting your engine!!!!!

Once the oil is gone, the filter only filters LARGE particles, not micro which are the wrose thing for your engine, mix that with your oil or the mineral oil that was sucked from the filter into your intake you you have a nice environment for wear!

I have seen the tested from a large company who decided to test K&N on all there vehicles to "SAVE MONEY" on filters since their trucks saw alot of dust.
They thought they would also get better MPG as well.
After 6 months of testing, they conlcuded that the K&N filters were worthless, that their vehicles had more problems and the MPG was not increased.

The oil was tested and it had extremely high amounts of microparticles.
They tested the oil on all the vehicles prior to using the K&N, using the OEM paper. The results were so high the company went back to stock paper filters.

Minor engine response and "SAVING MONEY" by using these filters is not worth it. K&N has a great marketing strategy.

I will see if I can find the tests, if I can??

These cars are not economical and we drive them for a reason. Trying to be economical on a filter element that can keep your engine running great seems like not the best choice! Changing a paper filter costing around $27 every 30K does not seem like a pocket book killer! I rather pay $27 every 30K then thousands later in new seals and rebuild job!!

Foam filters were rated MUCH better than paper and MUCH better than Cotton.

They use NO OIL! It is a 3 layer technology used on the DTM vehicles in Europe. The filtering capabilities were much higher than cotton and the flow was about the same as cotton. Plus the foams filtering lasted much longer than the K&N claims!

 

I guess we are sort of on the same page here. I will put up an add with a dyno chart in the classfied section sometime next week. I can´t do it right now because I am in Mexico. I won´t put in it this thread because it doesn´t apply.

K&N filters are popular with performance shops because they make a filter for just about any application you can think of. This means they only have to carry one brand and they can see to just about every customer. Plus K&N filters are so well known that they do sell themselves. People come in and ask for K&N. I don´t think thier stuff is that great but I don´t sell K&N so I have not dealt with them much. My biggest complaint with K&N is their "horsepower guarantee". The adds say things like "15 more horsepower guaranteed". Go to thier website and read the fine print and you will see the guarantee is only for an increase. It could be one horsepower at 3200 rpm and less everywhere else! Plus they require you to dyno it at your expense to show that there was no increase anywhere in the power band.

I have a ton of data on intake temps for various filter locations and air pressure variations with different set ups. My intake does locate the filter inside the engine bay. So does the factory. Like the factory I place the filter far forward right by the cold air source. Provided the car is moving intake temps are about the same as with the factory set up. When the car stops intake temps do rise quite a bit with either the factory intake or mine, however they rise more with mine. However even at the greatest temp difference (sitting in traffic a long time) my intake still provides more power as a result of greater pressure in the plenum.
Air pressure in the plenum is what its all about. My intake provides more air pressure in the plenum at just about any rpm and a lot more above 4000 rpm. It actually boosts air pressure above ambient! Provided the car is moving air temps are the same as with the factory box so that´s when gains are greatest.
If you want to see a picture there are plenty of them on my site at www.hiperformancestore.com. There is also a dyno sheet of my Cobalt Intake. That intake outperforms all the others without risking hydrolock. Sadly the Cobalt intake does not sell well and will be discontinued.

 

Clean setup. Such a system for the 164 would be interesting to see tested.

Only one thing, you mention (for a non supercharged or turbocharged system), "It actually boosts air pressure above ambient!". Nice thought but physically impossible, unless you inject outside source of energy via turbo or supercharger. Treat the engine as a black box, and increasing manifold pressure above ambient would require an outside source of energy which you don't have. Can't make something from nothing.

You have standing waves in the intake (and exhaust) determined by the engine rpm, cam profiles and timing, and manifold characteristics such as length and dia. You are modifying the waves or pulses by changing the intake. If you measure the manifold pressure along it's length you would find that some locations are higher and some lower in pressure, but the mass flow average through the intake will still be at ambient or less, just better than stock which is what you have achieved. Each engine design is sensitive to the intake design, such as tube length and dia, depending on how and where these standing waves develop, but you can never achieve anything better than ambient overall without outside help.

 

At high RPM air with my system air pressure in the plenum is above ambient. This was verified by Steve Rosser testing on the non AFM version using Megasquirt.

 

You raised the pressure in the intake above stock at high rpm open throttle by using a more porous and larger filter, but you can't raise it above ambient without outside help. This is analogous to changing the intake runners of the 94-95LS 164 to the 94-95Q runners, which match the intake size of the heads common to both the LS and Q, thus gaining about 20 hp at open throttle high rpm. A flow choke point has been relieved.

 

Want to bet? Lets say the looser has to donate a hundred bucks to the Alfabb.

 

Talk to your physics prof. If you claim it, you have to prove it. I'm not claiming any changes. I don't race for pinkslips.

Change the cams to wild overlap, and then you might have something, but you didn't so I doubt stock cams have enough overlap to get intake pulse charging (it ruins the idle and emissions). To understand what is happening in the entire intake, you would have to install pressure taps all along the length of the tube to get the pressure pulse profiles (intake pipes are like organ tubes with resonating pulses) from the valve to the filter vs rpm and load.

 

Del, I didnt mean to sound hostle. I have been stuck in a Mexican hotel for 4 days, not fun...

What would you like as proof? Would the data from an independent source count? Steve Rosser (the guy who wrote the book on Megasquirt use on the Alfa V6) tested the non AFM aftermarket system and has this to say.

"When tested the ambient air pressure was 98 kpa.
With the AFM & air box arrangement in place at full throttle the ECU would show 98 kpa inside the plenum up to 3000-3500rpm, then gradually drop down to 95 by 5000rpm and 94 by 6500, all at wide open throttle. I figured this loss of 3 or 4 kpa at maximum demand was a symptom of residual restriction from the components before the throttle valve. Now the good bit.

With the Greg kit installed and ambient air pressure still 98kpa I find that full throttle low to mid rpm is still 98 kpa, so no change here, or expected.
At 4000 rpm where previous version is already showing losses the new version maintains 98 kpa.
Above 5500 rpm the plenum pressure now increases to 99 and then 100 kpa and maintains this right through to 6800 rpm.

In short measurements of air pressure inside the plenum chamber are 5-6kpa higher than the previous modified and pretty good inlet system.

Not only has the restriction vanished but there is now a measurable RAM effect ! I don't know exactly how this comes about but suspect that as the air filter base is the shape of a large "velocity stack" and merges perfectly to an unribbed tube and elbow the system is not only unrestrictive but generates some positive RAM effect at high demand.

In short this is a fantastic product. I've gained 5-6 kpa air pressure which ought to be some 5% extra airflow into the engine and Air = Potential Power ! "

Short of meeting up with you, with a car and test equipment thats about the most solid proof I can offer. This is certainly not the only testimonial out there. I think my high school physics professor is dead by now. I don´t think he knew squat about cars anyway. I hesitate to start discussing physics because that always leads to trouble. Discussing the why it works this way is not to my benifit. I am more interested in proving that it does work.