Quote:
Originally Posted by cbergeron
Ah, this brings up an interesting point about recirc and Cd. In my VW Jetta, when I travel at highway speeds, when I turn on the recirculate for the AC, I begin to hear wind noise near the front of the windshield (passenger side). If I'm hearing it inside the cabin, I'm sure it must be hurting the Cd. I'm not hypermiling my Jetta, but its definitely an interesting thought.
The fresh air intake gets closed, which I'm assuming is why I hear the wind noise. I've planned to tape over the air vents in the front of my Aspire for this very reason.
|
A couple of ideas here -- just humble speculation, if I may
...
The recirc intake is generally on the passenger side under the glove-box, which may explain the noise.
Second, I would tend to think that not having to force air into the cabin would
decrease drag (like blowing air through a straw -- and the one-way flapper in the rear of the vehicle lets the fresh air flow out at its own rate). Avoiding this creates a cleaner flow?
Now for my situation: the cabin air intake is completely covered by the hood:
Hood Closed:
Note on the passenger side, the notch for the false panel...
Hood Open:
Oddly placed inlets...
The rubber seal should, well, seal -- but it doesn't. This makes Winter better and Summer a scorcher -- sucks engine bay air. You can smell what's going on under there (it's how an oozing valve cover and resultant oil burn-off was the tipping point for replacement).
I need to get a snorkel or something fabricated this Summer -- the windows rolled down should definitely increase Cd compared to a slight redirect (?). It may double as an ambient-air intake. There's a removable panel by the battery that's about 12" wide and a few inches deep. Not sure why this is here
The battery and wiring would need some genuine weather-protection. So there ya go...
Highway driving in the Summer with the windows up is a bake oven for this reason (even with the windows cracked). So the A/C comes in. I can't sweat too much for work purposes
.
Constructive criticism/suggestions are welcome.
RH77