benzito911

i want one of those

hieracity

wouldnt it be better if you just left it like this instead of putting a canister over it? free air flow...it can grab air from everywhere. I would still have that air hose in front of it to bring in cold air...thoughts?

c230kompk

has anyone purchased any items from BMC before, i did not find on their site what the return policy is, or if there even is one?

maverik259

if you didn't enclose it like so, it would be grabbing a lot of engine heat as well...being right next to it as such...if you research some CAI you'll notice all the good ones tend to extend the pipes down in front of the engine or as far left or right as possible with a heat shield installed to diminish he heat intake into the filter etc etc.

c230kompk

Just ordered my cf airbox today, ill update after installation

hieracity

i know in the 335i, there is a dual cone intake mod which is left open with the intake hose just pointing air in the general direction. and those cones are also in the middle of the engine kinda like in our engine. and tests were done which showed that the increased airflow more than compesates for the warm air that comes in from the engine bay...

thoughts...

maverik259

I'd be interested to see these "tests" and how accurate they are since the whole point of a CAI system is to injest cold air, not hot engine air...the colder the air the more dense it is and thus the increased amount of O2 to burn!

hieracity

http://www.n54tech.com/forums/showthread.php?t=2014

here you go. mind you though, it was for a different engine so it might not apply to the m271 engine. I just brought up the point for some healthy discussion

shivi1345

so let me see if I got this right..the temps actually run cooler with an open intake ?

It pretty much says that the air has to be cooled once it leaves the turbo (via the intercooler). So does it work the same way on our cars? (replace turbo w/ SC obviously)

essentially.....more air is better...even if it's hot air

that's what it's saying....right?

nuclearhappines

What he's showing is this:

Stock setup:
Intake temperature: 63*F
After intercooler: 100*F

Open filter
Intake temperature: 66*F (almost the same)
After intercooler: 97*F (3 degrees lower)

So with a 'hot air intake' he's showing a cooler temperature after the intercooler because according to him the pumping losses that were reduced by removing the air box make the turbo have to 'work less' to get the air in which increases the turbo's efficiency enough to show a cooler outlet temperature.

An FYI on compressor efficiency...

If a compressor efficiency is 60% for example , then
Outlet temperature = inlet temp / efficiency

so for an M45 which has about 60% efficiency an inlet temp of 66* would give an outlet temp of 110. The difference between 110* and what is seen at the throttle body (in this example around 97*) is the inter-cooler doing it's magic

One thing to note here. The BMW has ****ty intercooler to start with, so this result is surprising to say the least. A good intercooler brings you within 10 to 15* of ambient...i mean look at the start of the run, the intercooler starts at 77* for an ambient of around 55*

He states that the measured temps of 66 or so was about 10* above ambient after getting the car to warm up.

Assuming ambient is around 55 degrees and intercooler outlet temp is 97*.

Let's convert this to Kelvins:

65*F = 291 *K (10 above ambient for a good intercooler)
97*F = 309 *K (current IAT)

Then the car stands to gain 309/291 = 1.06 or +6% it's current power with a better intercooler that will bring the temps down (and the air density up). This is also the same amount of gain you can expect with a little bit of water injection.

Surprising results, but i'm not one to argue with hard data, especially on already soaked intercoolers

Cliff notes: The link posted shows COOLER air with a 'hot air intake' .. weather or not it was MORE air we'd have to look at a dyno showing more horsepower, leaner air fuel ratios, or an OBD log of the MAS readings ... but even if it's the same amount of air, it is cooler in this test.

nuclearhappines

PS: if you wanted to know for sure if this mod is good on your car (the benz)

Do 2 runs on an identical road (load) on identical weather (inlet air temps), one with the stock setup and one with the open filter.

On those two runs log these things:

MAS reading (grams per second)
Timing Advance (degrees)

If the open filter increases MAS readings (grams per second) without hurting your timing advance (due to significantly hotter intake temps , or engine knock) then the open filter is a power adder.

If the MAS readings don't change (or are reduced) or the timing is reduced then you have lost power.

MAS sensors measure air MASS ... mass is a combination of flow * times * density...

If the new filter gives more MASS then it should make more power. It doesn't really matter weather this mass is due to less cooler air or more hot air... as long as the total MAS has increased, then the engine is breathing more air, and can stand to make more horsepower, so long as this mass increase doesn't come with knock, timing retard, or limp mode then you will make more power with it.

maverik259

haha im really finding it hard to believe his inlet temps only increased 3* after removing the box...he has to have taken those readings right after starting the engine, lol...

c2304me

if anyone is interested in buying that bmc canister let me know i have one brand new with the box, i normally read the forums just never became a member so i wouldnt post, but i read this forum and it seems like a lot of people are interested and the only way i could post was to finally go and sign up for mb world. but anyways i have the canister for sale, brand new with factory warrenty and never been used still out of the box p.m me if interested.

Zillarpillow23

So you managed to bypass the left intake route all together and stuck with the right passageway that's directly in front of the airbox correct? The one that already comes closed off by the factory with that little plastic piece? See picture below.

Zillarpillow23

This was my K&N filter upgrade back in the day but I'm curious as to what the highlighted wire or sensor is and how did you bypass that? See pictures below.

nuclearhappines

i believe that's a baro correction sensor.

measures air altitude.

it can be located anywhere in the engine bay it doesn't matter...

you don't bypass it, just zip tie it anywhere no problem

Zillarpillow23

Thank you for this.

adzeladini

that is excelent work

dskompress24

can you pm detailed instructions to remove the airbox?
i think im going to throw in some custom piping, and a filter on the end for a nice CAI on my coupe, let me know what you guys think?

nuclearhappines

Thinking of buying the parts to do this mod now... about 1 month ago I was messing with the car and I swapped the grill plugs where the passenger side is now plugged and my drivers side is now open.

I also took out the 2 bend hose that goes from the airbox to the passanger side vent (which is now plugged) and drove the car like and noticed some good gains ...

The engine revved more responsively at idle ... and the car pulls harder especially going over the 100kph mark ... which is where I assume the air is moving fast enough to bridge the gap from the grill vent to the airbox without a significant intermix with the radiator's hot air... and diluting the intake mix...

It looks ghetto though like something is missing... so I'm thinking of doing this if anything for the looks of it ... and moreover, if this works now, it would work even better having ducted air from the grill rather than being open to the engine bay...

Question: Isn't the ECU physically attached to the airbox ? Is it just hanging now ?

Dimitris GT

hello everyone...
i have 2 questions: what did you do with the air sensor from the stock air box???
and the second what did you do with the cooling of ECU???
in the stock air box have a vented hole to ECU place!!!
by the way nice job// keep it up!!

FN-2187

the ECU is mounted to the airbox so I'm wondering what you did with it after you installed the custom canister?