[eNineZero]

Hey guys,
I just purchased a used aFe Intake for my 2006 325i Sedan. After installation the intake sounded amazing however the car did not run right. After assembling and disassembling the intake several times and creating my own gasket for the maf I was about to give up. I compared the stock intake and the aFe to find that the MAF sensor sits alot higher up in the intake tube on the factory box.


Issues: I experienced a huge loss in power between 4000-6000rpm, and very evident engine surging (power for 200 rpms , no power for 200 rpm, power, no power, etc.) throughout the power band at WOT.


Solution: I created a spacer for the MAF out of 1/2 inch MDF board. I also made a gasket out of 1/16 inch thick sheet of rubber to go between the spacer and intake tube. I did not need a gasket for the MAF to spacer since the sensor already has an o-ring, however the hole in the spacer must be perfect for the MAF to stay sealed. Longer bolts (extra 1/2 inch) had to be sourced.

Here is a diagram:





Outcome: The car now runs perfect, cannot feel the slightest stutter, power seems to be good and engine revs smoothly regardless of throttle input.


I am glad I decided to try this instead of giving up, as this is the best sounding intake I have heard for the E90/E92. I hope this can help solve some of the other members issues with this intake since research showed there is quite a bit of you with similar problems.

[tamster00]

I was hoping that aluminum heat shield would've been plastic/silicon, that would absorbed less heat and not rob power, good fix though!

[eNineZero]

Originally Posted by tamster00

I was hoping that aluminum heat shield would've been plastic/silicon, that would absorbed less heat and not rob power, good fix though!

Thanks! I don't believe that the shield is really robbing any power. I understand that it gets hot, but it does not have enough time to heat up the ambient air with the type of airflow the engine has. Yes, from a stand still or a gentle cruise at low speed I can see how the aFe would ingest some of the underhood air since the shield isn't sealed well, but once the car is moving and at WOT especially if you have some type of scoops it should have no effect on IAT. Remember that on a dyno the car stands still, and those fans are really nothing compared to a car moving at 20+ mph.

[MaximusJ]

Good job! I had the symptoms as you did with that very same intake. But I must admit your symptoms were waaay more present then mine.

I am a bit concerned by the seal between the MDF and the MAF over time and heavy rain / snow conditions; but time will tell!

I just find it ackward that aFe never steped up with this kind of fix. You should contact them and sell them the fixes ;p


Good job on that sir!

[eNineZero]

Originally Posted by MaximusJ

Good job! I had the symptoms as you did with that very same intake. But I must admit your symptoms were waaay more present then mine.

I am a bit concerned by the seal between the MDF and the MAF over time and heavy rain / snow conditions; but time will tell!

I just find it ackward that aFe never steped up with this kind of fix. You should contact them and sell them the fixes ;p


Good job on that sir!

Thanks. I am planning on getting an aluminum spacer made by a local machine shop. I used MDF board for temporary/test purposes.

[shazzy04]

Nice fix, I'm going to have to do this on mine

thanks

[soursamo]

I'll be the first to say put me down for one if you decide to get them machined!

[krnboy817]

so does this mean that this intake creates hp gains and no hp loss like most people say this intake tends to do?

[arctic330i]

Very interesting... I sold mine because of this issue. Once I hear this is a true fix I will have to look into it for sure!

[berserkerx]

I am one of the guys who just stuck with a stock air box and a K&N. If this is a real fix I may make the jump. But I am guessing this intake still suffers from heat soak?

[krnboy817]

Originally Posted by berserkerx

I am one of the guys who just stuck with a stock air box and a K&N. If this is a real fix I may make the jump. But I am guessing this intake still suffers from heat soak?

the theory is that the ambiant heat surrounding the intake isn't effecting the incoming air since the cooler air going into the intake is moving at a certain rate where at that rate, there is just not enough time for heat to be infused to make the air rise in temp.

this is true to a point but a lot of factors play a role to make this true. and one thing off the back that doesnt make it true for afe heat shield is that its paper thin aluminum, which over a certain period of time of exposure to heat it will be something that will transfer heat (metal holds heat and radiates the heat it holds.)

my other argument is in a tightly enclosed case this theory is possible but that heat shield isn't something that you can call tightly enclose space. and although the ambient heat my not transfer to the cooler air, but the hot air that is already infused with heat may leak into the very area the heat shield is supposed to create.

so for a stock intake box the theory can be applied, since it creates a tightly sealed enclosed space. but it cannot be applied to AFE heat shield since it does not create this encasement. and im sure there is a reason why BMW made the intake box casing material as thick as it is.

so the only way for AFE to be effective is when the out side temp is low enough to offset even after all the heat factors are added and still have the temp of the incoming air cooler than what stock box can hold.

[berserkerx]

Originally Posted by krnboy817

the theory is that the ambiant heat surrounding the intake isn't effecting the incoming air since the cooler air going into the intake is moving at a certain rate where at that rate, there is just not enough time for heat to be infused to make the air rise in temp.

this is true to a point but a lot of factors play a role to make this true. and one thing off the back that doesnt make it true for afe heat shield is that its paper thin aluminum, which over a certain period of time of exposure to heat it will be something that will transfer heat (metal holds heat and radiates the heat it holds.)

my other argument is in a tightly enclosed case this theory is possible but that heat shield isn't something that you can call tightly enclose space. and although the ambient heat my not transfer to the cooler air, but the hot air that is already infused with heat may leak into the very area the heat shield is supposed to create.

so for a stock intake box the theory can be applied, since it creates a tightly sealed enclosed space. but it cannot be applied to AFE heat shield since it does not create this encasement. and im sure there is a reason why BMW made the intake box casing material as thick as it is.

so the only way for AFE to be effective is when the out side temp is low enough to offset even after all the heat factors are added and still have the temp of the incoming air cooler than what stock box can hold.

So are you still saying basically that the stock intake with a K&N is still the best thing for our cars? Maybe I am a skeptic but I have always felt like an intake basically is just there for making noise for a high price.

[325xi-06]

i will have to try this fix also. as my car runs un-smooth :P

[RupertPupkin]

Originally Posted by berserkerx

So are you still saying basically that the stock intake with a K&N is still the best thing for our cars? Maybe I am a skeptic but I have always felt like an intake basically is just there for making noise for a high price.

Just installed the Injen SP1121BLK Intake in my 2006 330i. I have experienced no loss of power, surging, or anything negative at all. It sounds amazing and may have gained some power and responsiveness, but definitely didn't lose any. I have had the car sitting after long drives and then gotten in and there are absolutely no heat soak issues to be noticed.

I'm sure that with a thermometer and a scientific analysis it may be sucking in some warmer air, etc but the real test for me was real world experience and all I can say is it is night an day with the stock airbox.

Couldn't be happier with it.

[blazex4]

Originally Posted by jimmydever

Just installed the Injen SP1121BLK Intake in my 2006 330i. I have experienced no loss of power, surging, or anything negative at all. It sounds amazing and may have gained some power and responsiveness, but definitely didn't lose any. I have had the car sitting after long drives and then gotten in and there are absolutely no heat soak issues to be noticed.

I'm sure that with a thermometer and a scientific analysis it may be sucking in some warmer air, etc but the real test for me was real world experience and all I can say is it is night an day with the stock airbox.

Couldn't be happier with it.

Could this fit in the '06 325i?
I've been reading threads about power loss with the afe intakes

[RupertPupkin]

Originally Posted by blazex4

Could this fit in the '06 325i?
I've been reading threads about power loss with the afe intakes

Yup. Pretty sure its the same part number from Injen. Check their site.

www.injen.com

[1QuikWS6]

Innovative fix!

But how about everyone just NOT buying AFE intakes?

I see this problem day in & day out on the forum, resulting in quite a few AFE intakes being sold second hand on the forum.

You would think by now that people would simply quit buying the pieces of junk and send AFE a real message...

There are other intakes available

[velvetaudio]

Just curious, how did you figure out that the spacer would fix the issue? I would have never thought about that.

[eNineZero]

Originally Posted by 1QuikWS6

Innovative fix!

But how about everyone just NOT buying AFE intakes?

I see this problem day in & day out on the forum, resulting in quite a few AFE intakes being sold second hand on the forum.

You would think by now that people would simply quit buying the pieces of junk and send AFE a real message...

There are other intakes available

The AFE Intake is great, but has a design flaw which can be easily fixed. It's also the best sounding intake hands down. The sound part is the selling feature I believe, nobody buys them for power gains.

[onephattai]

Originally Posted by eNineZero

The AFE Intake is great, but has a design flaw which can be easily fixed. It's also the best sounding intake hands down. The sound part is the selling feature I believe, nobody buys them for power gains.

yes the sound is awesome but I feel like the intake sound gets a little softer after a few days. I don't know maybe it's just me. My problem with this intake is I don't have power in low rpm, like from 1k to 2.5k. If I apply more gas around these rpm range, then the car will surge which really annoys me. I'm thinking of doing what you did with the gasket. Hopefully it will solve my problem otherwise I'll have to go with something else. On DS mode, the car runs great. Still a little power loss at low rpm but no surging.
to the sound but it comes with a problem

[krnboy817]

Originally Posted by jimmydever

Just installed the Injen SP1121BLK Intake in my 2006 330i. I have experienced no loss of power, surging, or anything negative at all. It sounds amazing and may have gained some power and responsiveness, but definitely didn't lose any. I have had the car sitting after long drives and then gotten in and there are absolutely no heat soak issues to be noticed.

I'm sure that with a thermometer and a scientific analysis it may be sucking in some warmer air, etc but the real test for me was real world experience and all I can say is it is night an day with the stock airbox.

Couldn't be happier with it.

its because you just spent $200+ and your brain is trying to cope with money wasted by telling your self "there is a gain... there is a gain..." its a placebo effect. its like 200hp civic si feels different perhaps slower/lagging than 200hp gti because its not boosted, but in the end its still 200hp.

[RupertPupkin]

Originally Posted by krnboy817

its because you just spent $200+ and your brain is trying to cope with money wasted by telling your self "there is a gain... there is a gain..." its a placebo effect. its like 200hp civic si feels different perhaps slower/lagging than 200hp gti because its not boosted, but in the end its still 200hp.

I bought it for sound. I didn't expect gains and don't think there were any. I didn't say it did. I said it sounds great and have no issues especially the power loss everyone talks about. I said it MAY have gained some but even if it did I wouldn't be able to feel it. I've modded many cars before and know what to expect.

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