[Wurx]

When researching intakes, I found a lot of folks on the web saying an air intake is generally a waste of money and offers zero noticeable increase in performance.

In the end, I decided that I thought the AFE Stage 2 was worth it for me since it provides some induction sound and easier filter removal at a lower cost than a new Euro intake, so I went for it when it was on sale for $409 shipped. At the time, I was not aware that I could possibly find a used Euro intake and combine it with a silicon intake hose for less money.

After installing the intake on my otherwise bone stock N52, the most noticeable change is the sound, which is exactly what I was hoping for. It gives the car a much more sporty sound without having to go with a performance muffler that can get annoying. It's not quite as sweet of induction sound as the E46 M3 I had for a few years, but it's nice. I also found the car a little bit more "peppy."

To troubleshoot a lean mixture code that showed up the other day, I took the intake off and went back to the full stock airbox including the carbon filter. Gosh, when switching back to stock, it really revealed that the AFE intake was definitely a performance improvement. The car was more responsive with the AFE intake. The responsiveness along with the sound really did make the car more fun to drive, and I didn't fully appreciate that until removing it.

I'm not sure if it's just throttle response are actual power increase that I was feeling, but whatever it is, it makes the care more fun to drive.

Now, the one caveat is that I never did remove the carbon filter from my stock airbox, so I guess it's possible that most of the improvement I felt from the AFE intake was just from removing that carbon filter which can be done for free. I get that, but I don't regret getting the AFE intake because I happen to really like the sound, and I can easily go back to 100% stock if I need to.

[Biginboca]

I did some testing on the AFE vs a Stock Airbox with Rev Silicone and a K&N drop in filter. I’ll see if I can find it but I did document a slight improvement.

My feeling is the modified stock set up I described above would equal the AFE if you added a ram intake like some have done. Think Dinan n52 Intake if you aren’t sure what I mean.

[Biginboca]

Here you go:

https://www.e90post.com/forums/showthread.php?t=1474549

[Wurx]

Great info. in that thread! I hadn't come across that one. Thanks! I agree with you that some people may find the AFE a little bit too loud/unrefined.

I'm thinking of modifying the AFE to incorporate the Dinan ram air design and maybe seal off the vents on the front. I'm not sure if the advantage of completely sealing the Airbox to keep all hot air out outweighs any loss in airflow from plugging the vents or not.

If you can use a diagnostic app to monitor intake air temp and/or flow while driving, I would like to do a test with the vents on the front of the AFE open and then sealed to see if the intake air is cooler or not and if there is a difference in flow.

[Taskmaster]

It made more power than a Filter/carbon delete box I did a few years back, but that stock box didn’t have a Silicone Elbow.

The difference was 2-3whp. For the MAF troubles, just do the stock box, with the dinan Snorkle (no need to rub the whole hose) and a cone filter. It’s a lot more ‘work’ but it’s the best of both worlds and is cheaper.

[Biginboca]

While we are on the subject I think it’s worth dropping this here:

https://www.e90post.com/forums/showt...ight=dinan+cai

[6ixSpd]

Not sure about any power gains, but I love my AFE Stage 2 intake for the sound. The stock intake is way too quiet and really makes the car feel like a grocery getter. My exhaust is all stock except for headers and it's the perfect setup for my daily driven needs. Loud only when I want it, and in the cabin not outside

[desertman123]

Originally Posted by Taskmaster

It made more power than a Filter/carbon delete box I did a few years back, but that stock box didn’t have a Silicone Elbow.

The difference was 2-3whp. For the MAF troubles, just do the stock box, with the dinan Snorkle (no need to rub the whole hose) and a cone filter. It’s a lot more ‘work’ but it’s the best of both worlds and is cheaper.

dude just buy some cheap 330i (or something) and stay a while, we all know you want one

[rick100]

charcoal delete and k and n filter drop will have similar results for under 100 $ including the sound , throttle response and power gains ( or at least you would feel one)

[Taskmaster]

Originally Posted by desertman123

dude just buy some cheap 330i (or something) and stay a while, we all know you want one

If I could find a manual 325i for cheap, maybe.

[mike@x-ph.com]

Thank you for sharing OP

[Biginboca]

Just going to put this here, I had some time today and added this to the stock airbox.



Car seems just as responsive with stock airbox/k&n drop in/2.5” ram mod/4” corrugated intake tube to throttle body as it did with the AFE set up. This current home made intake set up up was less than $100. That’s for:

2.5” piping ($20) for Ram
4.0” piping ($20)* for Airbox to Throttle Body
K&N Drop In ($60)
Charcoal Filter Delete ($0)

*Rev Silicone would be better for stock and 3 stage manifolds but don’t think it will align with my n54 intake.

Also the sound is pretty similar comparing the AFE to the above. I’m going to make a pass tomorrow and see how the numbers compare, but I expect any differences would be barely measurable if at all.