[hetzle]

Originally Posted by BMW_Belgier

You want to convince me with a test from the guy producing and selling them...

You guys really have to try harder to convince me... For years now i'm reading test (even TÜV) and reading feedback saying the opposite what you are saying...

Go test it yourself then, I have a very hard time believing BMS (or most companies) would fake the results of an easily duplicate-able test

[BMW_Belgier]

Originally Posted by hetzle

Go test it yourself then, I have a very hard time believing BMS (or most companies) would fake the results of an easily duplicate-able test

Don't have to!

There are specialist for this kind of tests... TÜV said no to open intake and i'm not going to say they are wrong...

http://en.wikipedia.org/wiki/T%C3%9CV

[F104]

Originally Posted by hetzle

Go test it yourself then, I have a very hard time believing BMS (or most companies) would fake the results of an easily duplicate-able test

My 2 cents worth:.

With an open intake, there is now two paths for the air getting into the filter:
- thru the bit of original piping one has have left, but which has a fair degree of resistance through the 'hump' and direction changes
- thru the radiator and intercooler, which represent an enormous surface compared to the intake, and which simply results in warmer air

An 8+ minute idle test doesn't prove anything. The engine hardly burns enough fuel to heat the thousands of gallons of air going out thru it on idle in 8 minutes . My 320d actually cools down when idling after a motorway run, simply because the massive amounts of non throttled air going thru it.

The acceleration tests would prove something, if you measure the right things. Just showing OBD intake temperature after the intercooler is as valuable as showing the temperature on the moon. Although I agree we're not talking massive differences here, it is simply not correct.

So why would these test show similar intake temps after intercooler. For each degree in turbo inlet temp, the turbo outlet temp goes up a bit more than one degree. That causes additional expansion, which has to go thru the same turbo charger paths and intercooler piping. That means less molecules get thru it. Or in other words the turbo pressure ratio stays the same, but air mass flow decreases.
And then the intercooler sees hotter air coming in, but also less off it. Easier job cooling it down. So yes intercooler out temp will not change much, but now there is less air mass too.
There's no free lunch in science, if you start less efficient there's no way of improving on it.

And my guess is at 70mph constant speed the 335i engine takes in some 30-40 ltrs or air/second. The theorethic free air flow thru the intake channel after the hump (60cm2 cross section) at 70 mph is some 180 ltrs second (in easy rounded metric numbers, 108kph is 30 mtrs/second. That is 300dm/sec thru a 0.6 dm2 intake, or 180dm3/second).
Even if you reduce that by up to 50% due to friction losses (as it isn't exactly a straight inlet) , the OE intake can flow more cold air than 99% of driving conditions require.

[BMW_Belgier]

Originally Posted by F104

My 2 cents worth:.

With an open intake, there is now two paths for the air getting into the filter:
- thru the bit of original piping one has have left, but which has a fair degree of resistance through the 'hump' and direction changes
- thru the radiator and intercooler, which represent an enormous surface compared to the intake, and which simply results in warmer air

An 8+ minute idle test doesn't prove anything. The engine hardly burns enough fuel to heat the thousands of gallons of air going out thru it on idle in 8 minutes . My 320d actually cools down when idling after a motorway run, simply because the massive amounts of non throttled air going thru it.

The acceleration tests would prove something, if you measure the right things. Just showing OBD intake temperature after the intercooler is as valuable as showing the temperature on the moon. Although I agree we're not talking massive differences here, it is simply not correct.

So why would these test show similar intake temps after intercooler. For each degree in turbo inlet temp, the turbo outlet temp goes up a bit more than one degree. That causes additional expansion, which has to go thru the same turbo charger paths and intercooler piping. That means less molecules get thru it. Or in other words the turbo pressure ratio stays the same, but air mass flow decreases.
And then the intercooler sees hotter air coming in, but also less off it. Easier job cooling it down. So yes intercooler out temp will not change much, but now there is less air mass too.
There's no free lunch in science, if you start less efficient there's no way of improving on it.

And my guess is at 70mph constant speed the 335i engine takes in some 30-40 ltrs or air/second. The theorethic free air flow thru the intake channel after the hump (60cm2 cross section) at 70 mph is some 180 ltrs second (in easy rounded metric numbers, 108kph is 30 mtrs/second. That is 300dm/sec thru a 0.6 dm2 intake, or 180dm3/second).
Even if you reduce that by up to 50% due to friction losses (as it isn't exactly a straight inlet) , the OE intake can flow more cold air than 99% of driving conditions require.

Thanks my fellow belgian landsman

That is what i call a: very good and solid answer

If the open intake is so much better, why don't all performance car have them instead of those hyper-technical closed intakes???

[wdlfbio]

I get a great Whoosh sound most times I let my foot off the accelerator. Sounds very much like a Subby BOV. I'm glad I kicked down $200 to sound like a $20k Subby

[Alext]

BMW spend literally tens of thousands if not hundreds developing the stock air intake (which happens to be a proper sealed cold air intake) for their N54 engine for good reason.

I had a BMS intake for my 135i and can't say it increased power; in fact I noticed that on hot days (esp in traffic) it felt more sluggish than the stock intake back to back.

Some N54 flash-tuners have found consitently good results with the stock intake + drop-in. I have been personally recommended by a very well-known and established BMW tuning company to stick with the STOCK intake + drop-in rather than go for a DCI, at flash-only tune + exhaust levels.

[cbad335]

Originally Posted by F104

There's no free lunch in science, if you start less efficient there's no way of improving on it.

Yeah, the DCI has never made sense to me. The vendors who sell them swear it doesn't matter that the DCI sits in a closed engine bay sucking in hot air, but I just can't wrap my head around that one. And if you care what your engine bay looks like, for goodness sake, don't install a DCI. IMO, they make the engine bay appear stripped down and unfinished.

[BMWSOZE]

Originally Posted by BMW_Belgier

But you can all read that when you use

But where is that located

[Hoody335]

Makes your BOV sound incredibly loud.. Well much louder than stock intake

[StevenY.]

It sounds awesome and will help with a tune like JB4 on a map on higher boost.

[BMW_Belgier]

Originally Posted by StevenY.

It sounds awesome and will help with a tune like JB4 on a map on higher boost.

Does it?

Explain!

[Sam335ix]

I have had mine for 6 months now, it sounds good and there is no difference in performance what so ever.

[StevenY.]

Originally Posted by BMW_Belgier

Does it?

Explain!

Fail, I always thought it did. Guess not.

[G3333]

i have a brand new one for sale. pm me $175 shipped

[BMW_Belgier]

Originally Posted by F30ftw

i have a brand new one for sale. pm me $175 shipped

After reading this thread, i don't think somebody would buy it...

[Sam335ix]

I am removing mine during winter, it's way too Loud and annoying since I can't open up with winter tires. The cold start sounds horrible coming from the intake.

[ronny214]

Why not just go with a high flow drop-in filter (un-oiled of course)? Much cheaper, used the stock setup, and I've read that you can still get some of that "woosh" noise everyone wants.

[jsmonet]

Originally Posted by BMW_Belgier

Does it?

Explain!

bmw engineered the factory intake to function responsibly, efficiently, at 8lb of boost. even the least aggressive tunes turn that up to 12+, and most people are running something between 14 and 17lb. granted this isn't a huge turbo so you're not pulling world-shattering cfm, but there's a chance to outrun the efficiency of the stock filter in that scenario.

the stock setup flows quite well for stock tunes. that's why you probably won't see a big difference just dropping it onto a stock car. remember bmw's design constraints:
-low maintenance
-only needs to flow enough to support 300hp
-quiet, because many purchasers prefer -exhaust- noise over engine noise and they've been quite vocal about this over the years

that pretty much rules out an open-element filter. the cone-in-a-box idea is silly from a production standpoint because you then have to tool for that, driving per-unit costs up.

every facet of production is a compromise of some form.

I can't be the only guy who's done his homework on muscle cars AND owned a few turbo vehicles.

[Noncom23]

Originally Posted by ronny214

Why not just go with a high flow drop-in filter (un-oiled of course)? Much cheaper, used the stock setup, and I've read that you can still get some of that "woosh" noise everyone wants.

Which one, name , brand? I would give it a shot.

[Dark_Knight_335]

Originally Posted by ronny214

Why not just go with a high flow drop-in filter (un-oiled of course)? Much cheaper, used the stock setup, and I've read that you can still get some of that "woosh" noise everyone wants.

This. I got an HP AUTOWERK foam drop in a while back, and it has been great. Better air flow (however marginal) and the N55s just have that BOV sound by their nature, it even amplifies it to a small degree.

[Noncom23]

Originally Posted by Dark_Knight_335

This. I got an HP AUTOWERK foam drop in a while back, and it has been great. Better air flow (however marginal) and the N55s just have that BOV sound by their nature, it even amplifies it to a small degree.

Thx. I really like trying these kinds of things out.
No hijack implied.

[F104]

Originally Posted by jsmonet

bmw engineered the factory intake to function responsibly, efficiently, at 8lb of boost. even the least aggressive tunes turn that up to 12+, and most people are running something between 14 and 17lb. granted this isn't a huge turbo so you're not pulling world-shattering cfm, but there's a chance to outrun the efficiency of the stock filter in that scenario..

Oh bugger - we diesel owners then must have a major problem as we have these boost levels on box standard engines:

N47 (my engine): 22.5 psi (I reckon my remapped car is at 30psi+)
M57 (the 335d): 28 psi (I don't want to know at what level a tuned 550lbsft 335d is..)
N47 twin turbo (the 07 onwards model with really two turbo's): 29 psi

I can't read my actual max. boost pressures, as the pressure sensor I have only goes to 255 kPa = 37 PSI = 22.5 boost + 14.7 atmospheric.