Home made CAI (Possibly better then Dinan). Pics and details inside.

I'll try to be constructive as I am worried about your car.

This post is by someone else who was responding to a different unnecessary modification to the stock intake system..

Originally Posted by franka

It is precisely because the air intake faces backward that it does benefit from the ram effect and more. Think air pressure.

The air pressure immediately in front of the radiator is slightly higher than the air pressure say 3 feet to the side of the car. That's because the radiator is smashing into the stationary air in front of the vehicle and forcing some of it into the radiator or around the outside of the car just like a boat going thru water. The water piles up around the front of the boat. Well the air is piling up against the radiator which increases the air pressure in that local area. Facing the intake's pick up point towards the radiator places it in the high pressure area with some benefit. It's not a great benefit but it is enough to cause BMW to mount the air intake there.

Additionally, facing the intake point rearward is a clever way to prevent rain water from entering the intake while still taking advantage of the high pressure air. The air is much lighter and the pressure pushes the air into the intake whereas the water is much heavier and it's momentum prevents it from making the turn into the intake. It just goes straight into the radiator and slips thru the fins or drains down the face of the radiator. Very clever those engineers. Simultaneous ram air effect and water separation all free.

Nobody here thinks BMW is perfect. There is a reason that neither BMW or any aftermarket manufacturer have made a kit that does what you did. It's terribly risky with little to no benefit.

Originally Posted by SoCaLE39

^^^ you actually think you are going to get constructive comments from your setup?

Sure, here you go. Remove what you have done and put it back to stock. Otherwise I forsee a seized engine in your future.

Thank you, getting warmer to what i'm looking for. How exactly is my engine going to seize. The filter is protected from all sides (except the front). It's not in any of the pics but i built a water tight shield around it. Yes it will get wet in the rain, but will that really cause my engine to hydro lock? If you say yes, please explain. Thank you.

Originally Posted by 540ig5

Man you guys are impossible, it's gonna take me 4 days just to reply back to all the irrelevant nonsense you guys are writing.

YES believe it or not, paper towers and painters tape, it's a good way to protect your bulbs while your headlights are out, or is not BMW approved?

alright that makes sense what about cosmetic mods.. Thought you didnt care if you looked pretty. Admit it, we all do

ok here it goes, something constructive. honestly it is a good idea but first look at the cons and pros before attempting any of these tricks, remember that these cars will empty your pockets so saving a few hundred dollars now could put your engine and fragile components at risk. and they will not cost you $80

Originally Posted by 540ig5

Can somebody actually say something constructive here?

Everybody has! It's just not what you were hoping for.

Ok, seriously, your ingenuity is commendable, but your idea doesn't seem all that well thought out. Ballsy, yes. Smart, no.

Summary..

Creative

dumb idea

not saying YOU are dumb. Just the idea. Good luck

Originally Posted by 540ig5

Thank you, getting warmer to what i'm looking for. How exactly is my engine going to seize. The filter is protected from all sides (except the front). It's not in any of the pics but i built a water tight shield around it. Yes it will get wet in the rain, but will that really cause my engine to hydro lock? If you say yes, please explain. Thank you.

Well if you protected the filter in a water tight shield on all sides, you have eliminated your ram air then right?

All I'm saying is that the 540i intake system can suck up A LOT of air. In any point at which your filter gets submerged in a puddle or any pool of water, guess what, that intake system is going to suck up water. Once it does that, game over. Do a search and you'll see people have actually experienced this even in a less aggressive intake system then yours.

Now looking at the stock airbox setup , which actually performs quite well, you'll see that even if water were to enter the intake system, there are drain holes specifically located to prevent a hydro lock situation. This doesn't mean it prevents hydro-lock 100% however the odds are very different from your setup which doesn't provide these features which means the water only has one place to go, into the engine.

Originally Posted by andyffer

alright that makes sense what about cosmetic mods.. Thought you didnt care if you looked pretty. Admit it, we all do

I didn't say i don't care. I said that those mods ARE IMPORTANT, but they are last on my list. Meaning that I will do all other mods before worrying about what my car looks like. And just in case you were gonna bust my balls about the other things, I do have an engine cover and i do have valve covers etc. etc. They were removed TEMPORARILY, to deal with a separate issue.

Anything else? Do you have a problem with a spec of dust i left somewhere, or that I changed my transmission fluid, after all, the Germans say not to touch it.

Originally Posted by davenotize

ok here it goes, something constructive. honestly it is a good idea but first look at the cons and pros before attempting any of these tricks, remember that these cars will empty your pockets so saving a few hundred dollars now could put your engine and fragile components at risk. and they will not cost you $80

I did look at pros and cons, and I really don't see any except having my filter so low to the ground and partially exposed. But it's sealed all around except in the front. And from what i know, rain water getting on the filter will not cause problems. It's 5 feet of pipe from the filter to the throttle body, that's a long long way for rain drops to travel, especially "up hill".

All parts used are very high quality (except the air filter i think)

Originally Posted by pj-

I'll try to be constructive as I am worried about your car.

This post is by someone else who was responding to a different unnecessary modification to the stock intake system..



Nobody here thinks BMW is perfect. There is a reason that neither BMW or any aftermarket manufacturer have made a kit that does what you did. It's terribly risky with little to no benefit.

Thank you for that. Taken under advisement, i did not know that about the stock set up. The reason the filter is mounted in that area is because there is really no other place to put it. Also I'm not convinced that I will have water issues. Maybe if I buy a smaller size filter I can find room for it higher up.

Originally Posted by andyffer

Summary..

Creative

dumb idea

not saying YOU are dumb. Just the idea. Good luck

Why is it a dumb idea. What are the downsides to this set up. And please, if you are going to answer I would appreciate a detailed explanation to go along with it. If all you are going to say is "You'll suck up water" don't bother replying.

Trust me, I love this car and want what's best for it. And yes, maybe I made a mistake with this set up, but until someone can truly explain to me why this will not work, I can't change my mind cuz someone called this set up a home depot hack job.

An intake is basically a giant shop vac, it can easily suck up water 5'

im sorry 540ig5 but this is trully a dangerous idea. people have tried stuff like this before (look at bimmerforums) and have destroyed their engines. look for posts like "my car threw a rod" or stuff like that where their cars hydrolocked. if water gets in you are in a world of trouble. 4.4L engine so thats 0.55L of space within each cylinder at most (prolly less if they count the intake hoses and what not in their calculations), this is around how much water a poland springs water bottle holds. even one fourth to one half of that much water getting into a cylinder is good enough to destroy your engine. but then again im no expert but this is what the other forums say as well

Originally Posted by SoCaLE39

Well if you protected the filter in a water tight shield on all sides, you have eliminated your ram air then right?

All I'm saying is that the 540i intake system can suck up A LOT of air. In any point at which your filter gets submerged in a puddle or any pool of water, guess what, that intake system is going to suck up water. Once it does that, game over. Do a search and you'll see people have actually experienced this even in a less aggressive intake system then yours.

Now looking at the stock airbox setup , which actually performs quite well, you'll see that even if water were to enter the intake system, there are drain holes specifically located to prevent a hydro lock situation. This doesn't mean it prevents hydro-lock 100% however the odds are very different from your setup which doesn't provide these features which means the water only has one place to go, into the engine.

I said it's sealed from the bottom and back and sides, not from the front. So ram air still works. I obviously realize that putting my intake so log dramatically increases the danger. But unless I go into a one foot + puddle, I should have no issues. and I never drive my car thru water. Especially now, I will be even more careful.

Originally Posted by 540ig5

Why is it a dumb idea. What are the downsides to this set up. And please, if you are going to answer I would appreciate a detailed explanation to go along with it. If all you are going to say is "You'll suck up water" don't bother replying.

Trust me, I love this car and want what's best for it. And yes, maybe I made a mistake with this set up, but until someone can truly explain to me why this will not work, I can't change my mind cuz someone called this set up a home depot hack job.

I was giving a summary of responses.

I have no experience with water in an engine (and I hope you wont either), but from reading other's responses and picturing it in my mind, it seems plausible.

mist going into that intake + sudden increase in pressure due to the volume change = loads of liquid going in. i really think you should do something about this asap before something bad happens to your engine

Originally Posted by mrpumpk1n

mist going into that intake + sudden increase in pressure due to the volume change = loads of liquid going in.

Sorry, but can you be more specific, or should i say, rephrase that so I can understand exactly what you mean. Thanks.

it might seem like you need a lot of water to get your engine hydrolocked, it might seem like you need to go over a puddle. but what happens (based on fluid mechanics, look up von karman and navier stokes if you dont believe me) is that the lower you go the fluid acts as if its more like a solid layer (or rather denser?). so lets say your travelling down the road at 60mph on a rainy day, the mist being produced from the cars in front of you and the water being sucked up from the layer of road your in will be in the direct path of your intake. the intake is confined and does not expand or contract, so when the mist enters the intake, the sudden pressure increase will turn that mist into liquid instantly and itl be sucked into one of the cylinders. when that cylinder gets to the compression stage, the cylinder will compress because of the momentum from the other cylinders, however liquid (especially water) is generally incompressible, so at high pressure they behave like solids so pretend you have a brick inside your cylinder and then you try to compress it. this will break your connecting rods (hence the term "threw a rod") and your engine will be in for a major overhaul and cost upwards of 3-4k if your lucky.

Originally Posted by SoCaLE39

Poor 540i. Missing front bumper paint, engine covers, valve cover covers, hole in grill, jimmy-rigged intake system from fast and furious on the budget....it does appear your priorities are slightly off......

BTW to even state "possibly better than Dinan" is just asenine! Your 30min cold air with an autozone filter vs hundreds of hours of Dinan R&D.....hmmm.

Andyffer, stop encouraging.....lol

Alll hail the almighty DINAN

Originally Posted by mrpumpk1n

so when the mist enters the intake, the sudden pressure increase will turn that mist into liquid instantly and itl be sucked into one of the cylinders.

So what you're saying is that once any amount of water gets on the filter, that water is guaranteed to wind up in your engine?

where else do you think it will go? (if not right away, what will happen when the filter is saturated with water?)

Originally Posted by mrpumpk1n

where else do you think it will go? (if not right away, what will happen when the filter is saturated with water?)

I think there is not enough suction to make the relatively small amount of water on/in/around the filter to make that water travel all the way up to the engine. That's just what i think and I would love to be proven wrong here, rather then on a rainy day.

well you can take this as theoretical or practical. if you do the calculations out, if you sit there and draw out the diagram and do the vectors for all the forces and calculate out all the flow profiles of the water entering the engine through the air intake, odds will be against you. the good part is, when it comes to practicality, you have better chances of this not happening. However, do you really want to take the chances of this happening to your car? even if the probabilty was as low as 1%? Also about the suction, air is being sucked into the engine, otherwise it wouldnt run. if your exposed to water, its like drowning. water will be sucked in, you do not need a lot of suction power. but its upto you, if you can live with the possibility of the engine hydrolocking, power to you. if you want to discuss this further, you can pm me

You can clean your engine by shooting small amounts of water into the intake or a vacuum line. Rain water will not cause hydrolock. Let's not get silly. Ever clean an engine with solvent? I'm assuming you haven't. You literally suck liquid solvent up through a vacuum line. Guess what? No hydrolock. This has been common practice for the last....oh I don't know.....50 years or so.