[BullowM3]

i have an afe cold air intake on my 328. i love the sound it makes but i feel like im losing horsepower. does anyone know if it is proven to add horsepower?

[Shazmonkee]

i love the sound too, you're probably losing hp, and there's proof of losing power

[BullowM3]

true that. its so loud that i cant hear my muffler delete when my windows are open :[

[Shazmonkee]

lol pretty much. it still sounds good at least. If you prefer your muffler delete, just sell your AFE, go back to stock, and put a AFE or K&N Filter in there with charcoal delete

[spdy330]

I personally believe you actually lose a little power as you remove all back pressure from the closed airbox. I also believe the way to compensate for this is with some type of forced induction like a supercharger or turbo/s. The sound is great but that is all I think you will really get.

[MaximusJ]

Originally Posted by spdy330

I personally believe you actually lose a little power as you remove all back pressure from the closed airbox. I also believe the way to compensate for this is with some type of forced induction like a supercharger or turbo/s. The sound is great but that is all I think you will really get.

Indeed,

I used my aFe for a year prior to going back to stock and oh man I swear i'm never gonna have a open box intake on this car again. The lack of pressure results in a good 8 to 10 pounds of torque at low rpms.

On my japanese it wasnt that bad but for a e90, it really kills the torque.

I would be curious to see a REAL dyno just to compare.

[mike-y]

well, the factory intake system IS a cool air intake.. it gets the air right from the front grill. The AFE is open inside the engine bay..

think about it, these cars have a bellypan - that big plastic sheet the covers the entire bottom of the car. with the hood closed, cool air isn't getting in from the bottom of the car, the only air coming in is being pulled through the radiator (hot air) and whatever is still coming in from the factory snorkel, which is now being mixed with all that other hot air from the radiator.

[eNineZero]

The intake might be causing a power loss due to incorrect MAF reading. Some cars seem to be effected worst (my car, 2006 325i) than others by a possible design flaw. Take a look:

http://www.e90post.com/forums/showthread.php?t=574347

Every manufacturer has true cold air factory systems. Why would BMW be the only cars that don't benefit from aftermarket intakes? At WOT above 20mph I doubt the IAT is any higher with an aftermarket system (unless the filter is right by the exhaust with no heatshield). DYNO's are missleading in that aspect since the car sits still and draws in the ambient air underhood. If there is an actual power loss, it's far more likely that the MAF position is the culprit or other design flaws.

[alex2112]

I'm not too familiar with all the intake threads on here but I have had an Injen intake on my car since February and I've felt no loss of power or surging. Then again, I've felt no gains but it does sound good! I have seen all the AFE complaints though, so is the issue with power loss just with that brand?

[krnboy817]

im no scientist, but from understanding basic engineering, i think everyone with an intake (afe or injen) should try deleting the charcoal filter and slipping in a K&N filter.

minus the sound, compared to stock, i bet they will notice that having the mod done is better than getting an intake.

intakes (open box) usually benefit on higher band of the rpm when the engine is trying to suck in most air as it can... so less restriction makes sense. but on a low rpm, channeling the air is probably needed... i believe thats why the stock air box is big as it is so that it always holds some amount of air ready closer for the engine instead of the engine trying to draw in the air from out side.

plus when the air is being sucked in, its bound to create a vacuum, so a smaller closed box will have higher and faster vacuum pressure build than an open box would... thus in turn being a better intake.

so yes less restriction is better, but we all know we are bound to some restriction.

[WO1_rene]

Well my buddy here has a 330, with custom quad pipes and it added more power. In fact top end speed increased too. So maybe you should get rid of the muffler delete. Just saying. When i get back to america thats the first stop i'm making. aFe and performance muffler.

[Dr. Nate]

Thermodynamics

-Nate

[gaberoll]

Originally Posted by Dr. Nate

Thermodynamics

-Nate

Fkn thermodynamics, how does it work

[krnboy817]

Originally Posted by Dr. Nate

Thermodynamics

-Nate

physical science that studies variations on small variables such as temperature and pressure that interrelates to an outcome... i think.

[CoralRed335XI]

PV=nRT

[crazytaiwanese]

i would say a CAI would definitely benefit but an AFE intake is not a CAI .

lookup Stett, UR, and possibly Simota.

[krnboy817]

Originally Posted by crazytaiwanese

i would say a CAI would definitely benefit but an AFE intake is not a CAI .

lookup Stett, UR, and possibly Simota.

+1


simota v1 i think is one of the few that i believe someone in this forum has proven with dyno that it works.

[NorthernCAE90]

RESURRECTION IN 3...2..1!


What about a closed box like....................

This?
http://afepower.com/shop/details_new...no=54-81012-B&

[Eagle1oh7]

Originally Posted by NorthernCAE90

RESURRECTION IN 3...2..1!


What about a closed box like....................

This?
http://afepower.com/shop/details_new...no=54-81012-B&

That's what I got sounds great and throttle response feels slightly improved. Open air CAIs IMO draw more of that hot engine bay air in since that little "heat shield" only covers the bottom and not all around.

[willsull80]

Let me start off by saying unless you get air from the factory intake or a hole in the bumper on a E9X its not cold.

http://www.dinancars.com/shop/D760-9...pe.aspx#page=1

like this cold air scoop....


moving on.

I myself work in a world of thermodynamics and air flow. I'm one of the people who keep you cool at work and at home.

Ill start off by saying I have insulated my air intake system from the pick up snout right behind the hood latch brace all the way to the throttle body and I have dropped my true intake temp from a average of 218F to 200F. this is at idle and after a exact route pre and post heat shield. this is according to INPA readings not just me with my finger on the intake saying that's not as hot as it was! Sweet!

So this "cold air box you speak of" it is sucking up heat from everywhere it can get it under the hood and as far as I know hot air is only good in blast Furnas intake, and if you want to dry your hair. Not so much for making kitten power in our 3L NA Bimmers.

Also for all of these issues with MAF incorrect readings, in my world you need smooth air going across a CFM(cubic feet per minuet) monitor. The MAF in its own little way is a air flow meter, It looks at flow and temp to give the little German kid in your DME something to go on to make the injectors put the proper amount of fuel in to get the noise out of the tail pipe.

when you stick a aftermarket intake on you may not know it but you may be adding too much turbulence in the air flow for the MAF which is right next to the air box so it can not read the flow correctly, causing a "Lean" condition.

So that being said, the old saying holds true "you can not beat the boys in Detroit" , but in this case it's

"Sie können nicht schlagen die Jungs in München"

So when you think about what I said about air disturbance on the MAF look at the factory air box you just took out and look at how wide it gets before it enters the black hole of horse power in the middle. It spreads out for 2 reason one you want to slow the incoming air speed down so the filter it is passing though can actually keep the dirt that you have picked up doing burn outs in the parking lot in the filter and secondly it slows the velocity down just for a moment to correct some of the air turbulence up in the intake volute.

below is a little nerd knowledge. this may clear things up or it may make it worse who knows?

http://www.physicsforums.com/showthread.php?t=409704

Just know Smooth cold dry dense air is awesome and hot sweaty fat East German girl air under the hood air is none of that good stuff.

I hope this has helped some folks, I learned most of what I Know from Al Gore and well he invented the internet and you know if its not true it cant be on the internet right?

Just watch what you pay for mod wise and the "Dyno reports they post" You can modify any dyno report you want any way you want. heck the car on the dyno could be a viper and they can name it 328i so don't trust any picture you see unless you are standing there next to the machine. case in point the air scoops for BMW's how in hell do you dyno more horsepower with a car sitting still with a mod that may only work at 80+ mph.... do you do it in a wind tunnel???

just food for thought.

[6MT_Addict]

Originally Posted by willsull80

Let me start off by saying unless you get air from the factory intake or a hole in the bumper on a E9X its not cold.

http://www.dinancars.com/shop/D760-9...pe.aspx#page=1

like this cold air scoop....


moving on.

I myself work in a world of thermodynamics and air flow. I'm one of the people who keep you cool at work and at home.

Ill start off by saying I have insulated my air intake system from the pick up snout right behind the hood latch brace all the way to the throttle body and I have dropped my true intake temp from a average of 218F to 200F. this is at idle and after a exact route pre and post heat shield. this is according to INPA readings not just me with my finger on the intake saying that's not as hot as it was! Sweet!

So this "cold air box you speak of" it is sucking up heat from everywhere it can get it under the hood and as far as I know hot air is only good in blast Furnas intake, and if you want to dry your hair. Not so much for making kitten power in our 3L NA Bimmers.

Also for all of these issues with MAF incorrect readings, in my world you need smooth air going across a CFM(cubic feet per minuet) monitor. The MAF in its own little way is a air flow meter, It looks at flow and temp to give the little German kid in your DME something to go on to make the injectors put the proper amount of fuel in to get the noise out of the tail pipe.

when you stick a aftermarket intake on you may not know it but you may be adding too much turbulence in the air flow for the MAF which is right next to the air box so it can not read the flow correctly, causing a "Lean" condition.

So that being said, the old saying holds true "you can not beat the boys in Detroit" , but in this case it's

"Sie knnen nicht schlagen die Jungs in Mnchen"

So when you think about what I said about air disturbance on the MAF look at the factory air box you just took out and look at how wide it gets before it enters the black hole of horse power in the middle. It spreads out for 2 reason one you want to slow the incoming air speed down so the filter it is passing though can actually keep the dirt that you have picked up doing burn outs in the parking lot in the filter and secondly it slows the velocity down just for a moment to correct some of the air turbulence up in the intake volute.

below is a little nerd knowledge. this may clear things up or it may make it worse who knows?

http://www.physicsforums.com/showthread.php?t=409704

Just know Smooth cold dry dense air is awesome and hot sweaty fat East German girl air under the hood air is none of that good stuff.

I hope this has helped some folks, I learned most of what I Know from Al Gore and well he invented the internet and you know if its not true it cant be on the internet right?

Just watch what you pay for mod wise and the "Dyno reports they post" You can modify any dyno report you want any way you want. heck the car on the dyno could be a viper and they can name it 328i so don't trust any picture you see unless you are standing there next to the machine. case in point the air scoops for BMW's how in hell do you dyno more horsepower with a car sitting still with a mod that may only work at 80+ mph.... do you do it in a wind tunnel???

just food for thought.

Some excellent points, especially on turbulence. Well said sir

[willsull80]

Thank you sir, just doing my part.