TheOtherEric

So my car has seemed lethargic lately, and even my mechanic mentioned it. So after analyzing a LOT of logged data from track events, I determined that my car had lost 15 rwhp this year over last year. Obviously I was really worried...until I saw this today:

DOH!! I've been running like this all summer.

And in case you're still wondering why that's a big problem:


I don't know if I should blame the Porsche air filter that it collapsed or the Fabspeed airbox cover, but at any rate, the K&N filter went back in. Unbelievable.

I went for a test drive, and yup, definitely a difference. Kinda surprised you could so easily notice a 15 rwhp loss.

Mark in Baltimore

Eric,

Why would the ill-fitting air filter cause a loss in horsepower?

2ndof2

Looks to me like the filter got sucked into the intake tube and restricted airflow. Not sure if having the rest of an airbox cover would have prevented it from getting sucked in there like that. Is there anything else modified on your car that would significantly increase the suction at the intake?

How come you didn't notice this when you were checking your oil level? You DO check your oil level now and again don't you?

TheOtherEric

Because it collapsed right onto the intake! So the effective size of the filter is less than 1/10th what it should be, and this causes a big flow restriction.

A friend of mine just found the same problem in his R32 this week. There the ECU backed off the boost at 5800 rpm and so he got no boost above that. He fixed the air filter and it solved the problem.

TheOtherEric

Nah, my engine is so good that it doesn't burn any oil.

Mike J

Does the Fabspeed airbox cover lock down all the edges of the filter? I guess what I am trying to understand is how the filter got loose to begin with.

Did you notice the power difference when you removed the filter?

Cheers,

Mike

Mark in Baltimore

Okay, I see. Thanks, guys.

TheOtherEric

Yes, absolutely.

I don't know if the factory airbox would prevent this. I thought I've heard that maybe the felt air filter rim is a recent change (?). So I wonder if this was an isolated incident.

GeoT3

I would check the holding power of the upper clamps and see if is any fitment/sealing problems with the customer air box cover. how does it compare with the factory box?

I never had a problem with the factory air box cover... my guess would be that the custom air box cover is not holding the upper right air filter securely enough.

George

Marlon

Did you ever drive the car in REALLY rainy or wet conditions? Or give the thing a REALLY thorough bath? If so, your filter likely got soaked and subsequently SUCKED into the intake.

mrbill_fl

to me, it looks like its time to Drill the filter, and screw it to the airbox....

what kind of exaust?

your filter likely got soaked and subsequently SUCKED into the intake.
^
yep, that would do it too...

JasonAndreas

I'm willing to bet money that it was the POS ill-fitting fabspeed airbox cover. Their equivalent for the 964 (I've seen on it on several now) has similar problems that cause another set of issues that are really only noticeable with the engine out (unfiltered air).

AOW162435

The stock cover seems to clamp down very nicely, and is super rigid.

Andreas

NP993

X2 I've never seen or heard of this happening with the stock cover. And there's really no power difference. Why use the POS aftermarket bling-bling garbage?

Steve Weiner-Rennsport Systems

I think Jason is onto something here,....

For the past 12 years and better than a hundred cars, we have used the stock aircleaner cover and carefully cut away most of the center, leaving a rigid frame (using OEM paper element, of course) with no issues whatsoever.

JMHO, of course.