Mod for interior airflow?

[RH77]

Originally Posted by markweatherill

On a hot day, DIY brackets that allow a hatchback to be securely cracked/propped open a little would possibly help..? Maybe it would aid in finding the ideal rear roofline angle as an aside.

Has anyone tried this? I'd be curious to give it a shot...

RH77

[Frank Lee]

Of course somebody's tried it. And they dang near got asphyxiated by exhaust fumes.

[RH77]

Originally Posted by Frank Lee

Of course somebody's tried it. And they dang near got asphyxiated by exhaust fumes.

I transported a treadmill a few Winters back and had the hatch open about 6" -- all I remember was that it was COLD. Makes sense that the undercar flow forces the exhaust into the cabin. Buggah.

[jamesqf]

Originally Posted by Frank Lee

And they dang near got asphyxiated by exhaust fumes.

Well, that's one way to test your emissions control system :-)

[Xringer]

Originally Posted by RH77

Has anyone tried this? I'd be curious to give it a shot...

RH77

I've driven around town with my rear hatch window wide open and
never smelled anything. But, I did have my side windows down a bit..
Gave me great ventilation. The pneumatic(?) lifters hold it up pretty well.

Maybe I should tilt it up and lock it down at the tear-drop angle,
and do a highway speed test..?.

[aerohead]

Originally Posted by RH77

Has anyone tried this? I'd be curious to give it a shot...

RH77

In the recent past,this would net you carbon monoxide poisoning.With newer,cleaner engines this may not be as big an issue,however,you would still be inviting the the outdoors in and from the direction of your own exhaust pipe.I have carried large items in a hatchback which necessitated propping the hatch open,and I suffered every mile 'til I got to my destination.The reason the cowl is used for a ventilation inlet is that it is at a relatively high static pressure ( NASCAR teams breathe their engines from here ) and the air source is away from the tailpipes of the car in front of you.Engineers try to cite the air outlet such that a relatively constant pressure differential is present across the cabin,rather than building into a hurricane draft,as speed increases.They're thinking air changes more than evaporative cooling.I've used auxiliary electric fans to increase air velocity across me.The proliferation of air conditioning has turned ventilation design away from passive,to forced air systems.Kinda hard to modify.

[RH77]

Originally Posted by aerohead

In the recent past,this would net you carbon monoxide poisoning.With newer,cleaner engines this may not be as big an issue,however,you would still be inviting the the outdoors in and from the direction of your own exhaust pipe.I have carried large items in a hatchback which necessitated propping the hatch open,and I suffered every mile 'til I got to my destination.The reason the cowl is used for a ventilation inlet is that it is at a relatively high static pressure ( NASCAR teams breathe their engines from here ) and the air source is away from the tailpipes of the car in front of you.Engineers try to cite the air outlet such that a relatively constant pressure differential is present across the cabin,rather than building into a hurricane draft,as speed increases.They're thinking air changes more than evaporative cooling.I've used auxiliary electric fans to increase air velocity across me.The proliferation of air conditioning has turned ventilation design away from passive,to forced air systems.Kinda hard to modify.

That has been the problem -- the rubber seal between the engine and vent inlet has deteriorated over time and draws-in hot air. When the valve cover gasket was oozing oil and toasted on the block and header, the "aroma" wasn't the best Since that's fixed, my next project may be to repair the seal and invest in a fan.

If I crack the passenger window and turn the air on recirc, I can get some decent air movement. Even with the recirc off, at highway speeds there's plenty of air movement -- even with the blower in the "off" position -- but it's hot air.

But alas, it's A/C season for a while unless I'm not doing work-related stuff.

RH77

[craig5_12]

I have a long commute (60 miles 1 way) and in the summer it's over 100 a lot of the time. I don't have A/C...something wrong with the compressor...so I drive with the windows down. It's ridiculously hot and I need to go buy some beaded seat covers I suppose. I'm suffering for now though.
Wondering:
1) If I drive with my rear seat folded flat and open up some sort of duct to the outside through my trunk, this could help alleviate the reduced drag from the open windows as well as improve the wake...right?
2) What affect does having the sunroof open along with both windows have on MPG? (car specific I'm sure...I need a scanguage...)

[cfg83]

jamesqf -

Here's my idea. Crack the rear passenger window down maybe 2 inches. Get something like a half-circle pipe. Aim one end just barely into the airflow. Aim the other end at the back of the driver's head.

My idea is that you will lose some aero, but you may get the best "bang for the buck" because you should be getting pretty fast air flowing onto the back of your head (as opposed to your face, which would make your eyes water).

You could test this by having someone hold the "half-pipe" to the window while aiming it at the back of your head.

PS - Maybe the pipe should be conical, large intake to small outlet.

PPS - It might be more efficient to have the pipe cut in half like a Jai-Alai glove so that you capture more incoming air through the window, as opposed to the diameter of the pipe :

The Cesta


CarloSW2

[Frank Lee]

You may find that a duct in that region brings exhaust gasses into the passenger compartment.