Yeah, you're probably thinking something weird just by the topic name.
But thats about as close as I could get to describing it. Let me explain.

With one or both of the back windows down, and driving about 40 miles an hour or
above, I get a 'helicopter' effect inside the car. Its Hell on my ear drums, and to me,
is similar to a helicopter sound.

All I know is that I seem to be the only one who notices it. Whenever I have a friend
in the car, they can't even tell. I kid you not, it practically beats on my ear drums.

Has any one else encountered this in their xB, or have some type of explanation to
this odd occurrence? Maybe just the areodynamics of the rear windows and the air flow
through them?

By the way, if all the windows are down, the effect is null. It only happens if one, or
both of the rear windows are down, even a little.

 

Happens in my car too... Has something to do with the pressure inside the car but im not sure- But what I do to fix it is to roll down the fronts a little bit and that cuts it out-
Hope that helps you.

 

Yeah, rolling down the front windows does help. I was really just checking to see
if anyone else had encountered this as well.

Like I said, anyone who's been in my car say they don't notice it. I thought maybe
I was going insane or something. o_O;

At least I know its not just me.

 

it's normal for 90% of cars. my moms intrepid does it at 15mph. but yeah it's a negative pressure thing.

 

It's just like blowing air over the top of a beer bottle to make
it whistle...except on a MUCH larger scale, which means a
lower note.

With my dual sunroof setup open, I get this 18Hz beat like a
helecopter. I just open the side windows just a hair till the
pressure levels out and the beating stops.

 

it does it to me too .... i keep forgeting it does that......


infact it just did it to me today as well on my way to work lol i was doing 80mph and it was killer to my ears!!!!


OH.... maby i should explain that i was taking the beltway around DC where everyone does at least 80.

but other than that.....

my car love,
i do


lol sry had to get some starwars in here

 

all cars do it, just barley crack the front ones and that should get rid of it.

 

get the jdm toyota or esam window visors ...problem solved....atleast for me....cost a grip but totally worth it...

 

yea my car does it. I hate it and cant get all the windows opened fast enough to counter that sound. Would like to have some subs though that would get that loud.

 

CORRECT!!!! Just crack the fronts a little.

 

has anyone ever driven a minivan? the rear most windows can flip an inch or two to increase ventilation and kill that beating sound.

wouldn't that be an awesome mod for the box to have those motorized like in the van? too bad the electrical is beyond me...

 

This happens to me also. But just curious, what is the point in having the back windows down and not the front anyways?

 

I guess it isn't just an xB thing because it happens in my xA too. Dang it hurts that stupid sound.

 

It's common on many cars. When you've got all that air rusjing in, it needs a way to get out. So it will push out the same hole it's coming in but can't beat the pressure of what's coming in, so it forces itself out in spurts, so to speak. Like letting water run into a Coke bottle. Eventually it is fighting to get the water in and out of the same opening.

Another effect this has is if you only roll the front window down, you'll feel the wind hitting you upside the head . Crack the back an inch or 2 and it goes away.

The venting windows like Special Sauce refers to is something I've pondered for a long time. My minivan's got power rear vents... My Box needs them too!

 

i also notice the sound in my xA

 

Some of the only cars I ever had that didn't do that were some early-seventies Volvo sedans (142E and 164). Just under the rear window they had a vent the full width of the window, with a one-way 'valve' (a concealed rubber 'flap' hidden behind the narrow grill-like slots).

Whenever the interior pressure exceeded interior pressure, the vent would equalize them and no thrumming.

It was weatherproof and even pressure-washer proof, yet kept the interior much more livable.

I'm wondering if there is a convienient negative-pressure area at the back of the xB where a similar 'pressure reliev valve/vent' could be placed.

(Those automatic rear vents also induced reasonable airflow through the cockpit while 'at speed' if the heater/air conditioner controls were set to fresh air - without even having to turn the fan on.)

 

Its even more annoying on the tC. With just 2 windows, you basically cant open just 1 at a time. Its all or nothing.

 

hmm...i didnt notice that. i must try it when i drive the xB.

 

Hmmm. I didn't know that this problem was present with a lot of other cars.
But then again, the only other car I've owned before my xB was a Civic CRX,
and that only had two windows... -_-



I only roll down my back windows because I'm trying to get airflow into the car,
but since I have long hair I can't stand the wind tossing it around from the front
windows. Lots of people can deal with it, I'm just one of those people who can't.

Bugs the crap outta me. >_<