[tylerhart_21]

I have seen some people having the euro air box with cars in the US. But never knew what is the big difference besides the shape of the air box and the air filter. If anyone knows what the difference is let me know.

[roblese90]

I just installed the euro box on my 328i. The car feels a little bit more responsive but not huge. I guess the stock air box has a non removable carbon filter as well as the paper air filter that restricts air flow a bit.

[The Nightman]

I've gone back and forth and have not noticed significant differences. With that said, the European airbox does not have the charcoal filter that absorbs fuel vapour off-gassing for emissions purposes. You could cut that filter out of the NA box too for possible gains (https://www.e90post.com/forums/showthread.php?t=1584439). The European filter may also have more surface area, and it is easier to service than the NA filter.

I did notice that the NA box inlet is smoothed (like a velocity stack) while the Euro one was not. However, I like to think that the Euro airbox is the intended intake for this engine, so I stuck with that.

[fravel]

Performance wise - not much.

Aesthetically, I think the euro box looks a lot better in the engine bay.

Biggest benefit is ease of maintenance. With euro box you just gotta pull the lid off. NA version requires you to pull the entire airbox out.

Pro-tip: don't pay $300 for one. I got mine for around $75 using the german ebay site.

[bluewater328]

Originally Posted by fravel

Performance wise - not much.

Aesthetically, I think the euro box looks a lot better in the engine bay.

Biggest benefit is ease of maintenance. With euro box you just gotta pull the lid off. NA version requires you to pull the entire airbox out.

Pro-tip: don't pay $300 for one. I got mine for around $75 using the german ebay site.

There are a few european scrap part companies you can buy direct from as well. Mine even came with a filter...and a few lucky ones have gotten the IAT as well.

[rick100]

K and n filter with charcoal delete.

[CTinline-six]

I like my Euro box with silicone intake boot. I have also gone back and forth to stock to compare. I think it is worthwhile for easy air filter access, and the increase in throttle response at initial throttle tip-in, at least on my GM Automatic equipped car. It just seems to have a bit less pedal lag, and the transmission shifts a tad bit smoother. I don't think there is any measurable power increase, and I wouldn't pay a ton of money for one, but I do think it slightly improves the drivability of the car.

There is also a slightly different intake sound at wide open throttle, but otherwise there is no sound difference.

[tylerhart_21]

So what I am hearing for you guys get the air box cheap cause it has it's advantages over the NA.

[tylerhart_21]

Originally Posted by bluewater328

There are a few european scrap part companies you can buy direct from as well. Mine even came with a filter...and a few lucky ones have gotten the IAT as well.

Do you know any of the companies off hand?

[lowrydr310]

How does the euro intake sound on the N52? Any different than the US one?

One design aspect of air intakes for US-market cars is to minimize noise levels. I used to own a Toyota truck that had all sorts of goofy plastic tubes and boxes connected to the air intake. Once removed, the intake had a nicer sound that was slightly louder but not too bad.

[bluewater328]

Originally Posted by lowrydr310

How does the euro intake sound on the N52? Any different than the US one?

One design aspect of air intakes for US-market cars is to minimize noise levels. I used to own a Toyota truck that had all sorts of goofy plastic tubes and boxes connected to the air intake. Once removed, the intake had a nicer sound that was slightly louder but not too bad.

I mean there are a few Youtube videos out there. But generally, the sound difference is the common change from a flat filter to a cone-based one (Euro ones have a cylinder version inside). Add a silicone elbow in place of the intake resonator and you get a nice intake sound that's noticable. Power wise...meh...negligible if you would just remove the carbon filter off the stock. So this job is more aesthetic and ear service vs performance.

[lowrydr310]

Originally Posted by bluewater328

ISo this job is more aesthetic and ear service vs performance.

Louder = Faster right?

Maybe when it's time to replace my air filter next year I'll swap it, but for now I'm sticking with what I have.

[tylerhart_21]

Originally Posted by lowrydr310

Louder = Faster right?

Maybe when it's time to replace my air filter next year I'll swap it, but for now I'm sticking with what I have.

But if you want some more sound I heard the silicone inlet helps. Maybe a secondary air intake would add sound and power but not sure. I know some people have done this mod on here.

[Silnismo]

You lose a tiny bit of low end torque at lower RPMS but pulls much harder after 3k. Well worth the purchase.

[caldep]

I made the change to the European air box last year. I found online someone had performed and published flow tests with various OE and aftermarket intakes, the European airbox, and the US air box with and without the charcoal filter.

Short story, the performance intake (can't remember if it was the BMW or the turner) flowed the best but not by a wide enough margin over the European air box, to me, to justify the added cost over a German Ebay European air box.

The US air box options flowed the worst. The differences in air flow did not seem like they would make a large difference in our NA engines though.

My experience:
Much easier to change the air filter. The air filter is more expensive. Engine compartment looks cleaner with the European air box.
Can't really say it pulls harder (I have since had a 3-stage manifold and tune added). It did change the intake sound a bit (louder and different note). It seemed that the engine revved faster under no load. However, I always felt the engine spooled up slowly except for the first 100 miles or so after an oil change. I monitor my gas mileage with every gas fill up (I only fill my tank, never partials) but did not see a statistically significant change in gas mileage (would indicate a potential change in volumetric efficiency) but I do not drive hard enough for this to show up. Would need to drive fairly hard otherwise the engine management system (maintaining AF ratios and combustion efficiency) will make it hard to notice such a modest improvement.

i am glad I made the change and would do it again (paid around $85 with a filter and MAF). Do not use the European MAF though. My experience matches what most of the others have reported; it feels good, sounds nice, numbers say it's a good choice, but not significant.

[hassmaschine]

Originally Posted by Silnismo

You lose a tiny bit of low end torque at lower RPMS but pulls much harder after 3k. Well worth the purchase.

you're not going to lose torque anywhere because of an airbox. Maybe an open cone filter, but not one that was designed for the engine..

[Silnismo]

Originally Posted by hassmaschine

you're not going to lose torque anywhere because of an airbox. Maybe an open cone filter, but not one that was designed for the engine..

I am basing my opinion off experience, if you have done it and had a different experience good for you but I stand by my statement.

[hassmaschine]

Originally Posted by Silnismo

I am basing my opinion off experience, if you have done it and had a different experience good for you but I stand by my statement.

based off an ass-dyno?

[rjahl]

Originally Posted by caldep

I made the change to the European air box last year. I found online someone had performed and published flow tests with various OE and aftermarket intakes, the European airbox, and the US air box with and without the charcoal filter.

Short story, the performance intake (can't remember if it was the BMW or the turner) flowed the best but not by a wide enough margin over the European air box, to me, to justify the added cost over a German Ebay European air box.

The US air box options flowed the worst. The differences in air flow did not seem like they would make a large difference in our NA engines though.

My experience:
Much easier to change the air filter. The air filter is more expensive. Engine compartment looks cleaner with the European air box.
Can't really say it pulls harder (I have since had a 3-stage manifold and tune added). It did change the intake sound a bit (louder and different note). It seemed that the engine revved faster under no load. However, I always felt the engine spooled up slowly except for the first 100 miles or so after an oil change. I monitor my gas mileage with every gas fill up (I only fill my tank, never partials) but did not see a statistically significant change in gas mileage (would indicate a potential change in volumetric efficiency) but I do not drive hard enough for this to show up. Would need to drive fairly hard otherwise the engine management system (maintaining AF ratios and combustion efficiency) will make it hard to notice such a modest improvement.

i am glad I made the change and would do it again (paid around $85 with a filter and MAF). Do not use the European MAF though. My experience matches what most of the others have reported; it feels good, sounds nice, numbers say it's a good choice, but not significant.

I've seen no air box flow data that shows an increase within the range of the actual flow requirements for this engine.

[Silnismo]

Originally Posted by hassmaschine

based off an ass-dyno?

Yuppp

[hassmaschine]

Riggght. I'll trust the actual dyno results then...

[hassmaschine]

Originally Posted by caldep

i am glad I made the change and would do it again (paid around $85 with a filter and MAF). Do not use the European MAF though. My experience matches what most of the others have reported; it feels good, sounds nice, numbers say it's a good choice, but not significant.

the euro MAF is identical to the US MAF. Some EU market cars came with an IAT, which doesn't have a MAF at all - if that's what you mean. But you can use just the IAT and no MAF, but you need the proper calibration for it or it will run in limp mode.