Cold Air Intake

First, let me say that I'm not intending to start a battle here.
Second, as much as I know some people are huge proponents (and opponents) for FI, I'm not looking for FI comments here. Note the title.

What I want to see is everyone's opinions and arguments for and against Cold Air Intakes.
So far I've seen:
-Stick with the stock air box but upgrade the filter. BMW has already manufactured a great car. There's no point in altering it.
-Go with a cold air intake, but keep it up near the headlights (e.g. aFe, Gruppe M, etc). You don't want to risk ingestion by putting it too low, but you definitely want more air in.
-Go with a cold air intake and put it low (Carbonio shielded). Cold air is dense air, and dense air brings more power.

As you're chewing on that and coming up with a response as to what you think is the right way to go, keep this in mind (from Carbonio's FAQs page):

Will the system suck up water in the rain or if I go through a puddle?
The effectiveness of a cold air intake system depends on positioning the filter where the coldest, freshest air is available. By necessity, this means having to place the filter outside the engine compartment, in an area at the front of the vehicle where it is more exposed to the elements; consequently, it would be misleading for any intake manufacturer, including Carbonio, to suggest that there is no risk of water ingestion. Our testing suggests, however, that there is a minimal risk of water inhalation under normal driving conditions.

The greatest chance of water inhalation occurs if the filter is either partially or fully submerged (say when driving into a very deep puddle). With the Carbonio system, the filter is positioned in front of the wheel well, above the centerline of the wheels. In order to fully submerge the filter, you would have to drive for an extended period through over 15 inches of water. A much smaller risk is posed by ambient moisture (i.e. rain being ingested from the outside). Here again, the shielded position of the filter -behind the bumper and in front of the wheels- means that, short of driving in sustained monsoon conditions, water inhalation should not be an issue.

As the above suggests, your best defense against the risk of water inhalation is to exercise a minimum amount of care and common sense. Just as you would not charge into a one foot deep pothole with your brand new alloy wheels, on those very rare occasions when the weather turns exceptionally poor, be aware of excessive amounts of standing water in the road.

Now I know a manufacturer isn't going to speak poorly about one of their products, but it makes sense. I don't mean to slight the conversation towards the Carbonio option, but I've never heard a counterpoint for these types of CAIs. We've all heard the rest.

That's enough from me.
Let's hear it...

Stay out of the deep water, it's not a puddlejumper lol

I would say as long as it's shielded properly and you aren't splashing water up on it, and its not somewhere where water could come straight into it as you drive (ie right behind a grille) you should never have a problem with ingestion with common sense. When I finally get around to getting a CAI, it WILL be mounted down low, not in the engine compartment.

PERSONALLY, i love my CAI.

It gives amazing sound, frees up some missing horsepower and looks great in the engine bay

It does however have ONE downside….…...

I have found that the weather plays havoc with the performance of my car. Don't get me wrong, she is ALWAYS fast, but on the warm, dry days she is not as responsive as the cooler ones.

Mind you, she is still faster and better when the CAI is not performing perfectly than with the stock intake ***61514;

Basically what I am saying is that EVERYONE with a straight 6 should have one but be aware that you may get performance fluctuations depending on the air temperature/moisture content.

Basically what I am saying is that EVERYONE with a straight 6 should have one but be aware that you may get performance fluctuations depending on the air temperature/moisture content.

Anyone with an air-breathing engine should be aware that atmospheric conditions at any point in time will affect the performance of their engine.
If you want a more in depth discussion about it all, take a look at a pilot's ground school manual. There's a whole chapter discussing conditions and engine performance. Ever notice an airliner climbs out of an airport on hotter, more humid days?
...and their engines are literally giant FI engines.

Long story short:
+1 Anything with an air breathing engine will perform differently based on the weather.

As for my view on the topic, I'm interested in getting a low-mount CAI. Anyone opposed to them? I want to hear a different opinion.

I would be very careful doing this mate

Hydrolock is VERY expensive to fix, though i guess is not common. What is more likely is that the filter will get very dirty, very fast and will need A LOT of cleaning

Originally Posted by Pirate_copy

I would be very careful doing this mate

Hydrolock is VERY expensive to fix, though i guess is not common. What is more likely is that the filter will get very dirty, very fast and will need A LOT of cleaning

+1
You have a VERY slim chance of hydrolocking your engine. people do not realize how much water it would require, AND that all that water would need to end up in ONE cylinder!

I do however know someone that this happened to. They were driving an Audi A4 with a CAI mounted in the lower grill area, ahead of the radiator. This is a very low location and again, it is not sheilded by anything. He drove through a 9" deep puddle and BANG! Cracked head. VERY, VERY expensive fix.

Now, they make pre-filters that do not allow water to enter the filter, and they also make a Bypass filter. AEM makes them. Basically they go downstream of your cone filter along the intake pipe and if the main filter ever sucked up enough water, it opens the bypass valve and allows air in through there. It will also occur if your filter is very dirty.

Yes, you would be sucking hot air at that point, but would you rather loose some performance, or loose your engine? Plus, you shouldn't need "performance" when it's raining!

I wouldnt be too worried about hydro lock as long as you dont drive through puddles, and especially if you have the bypass. My best friend has a 350z with a Nismo Intake, and he suspects that the bypass has saved his engine once, because his car was parked, and the parking lot flooded with about 6 inches of water. He didnt have to worry about any problems.

My Bimmer had a personality transplant after I had a K&N Apollo CAI fitted

Yeah, I left out the point that it's shielded, which takes some of the risk out.

True true

i installed a simota CAI 3 weeks ago on a 318i automatic. i love the sound when you step on the gas and there is an improvement in 1st and 2nd gear. i just need a customized heatshield. does anyone have a pic of their heatshield? should i get one done in fiberglass or aluminium?

heres a pic:

don't mind the sticker hahahhaha

The pics in my garage show my heatshield mate

http://directory.bimmerfest.com/user...ser&UrId=50884

it just makes sense to straighten out the flow leading into the engine. no matter how great BMW is they did not make a factory box without inherent turbulence=inefficiency...anyways, who can argue with the increase in bad ass engine noise

It is winter here at the moment and I notice a difference in sound with the colder air outside - 10C. Is there any point in having a CAI in a 318is with an M42 engine? I do have a chip and a sports exhaust (Remus).

Unfortunately, the MAS on the M42 engine doesn't really lend well to a CAI buddy. You will feel some gains and the sound will be amazing but you will not see the gains the straight 6 feels

HOWEVER, with your exhaust and chip, i would DEFINITELY get one to compliment the setup

I have a stock 2004 Z4 3.0i and want to start enhancing performance. What is the best cold air intake for this car?