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Thread: Opened or closed rear windows when racing SWB car

  1. #1

    Opened or closed rear windows when racing SWB car

    Been racing a SWB car for a year or 2 and noticed some cars have the rear windows open and some closed. Is there a time/speed advantage either way at race speeds? Thanks for your comments!

    -Chuck

  2. #2
    Senior Member ejboyd5's Avatar
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    My rear quarter windows haven't been closed in 40+ years.

  3. #3
    Member #226 R Gruppe Life Member #147
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    The folks closing the rear 1/4 windows are probably getting exhaust backwash in the car.

  4. #4
    Yes, I get a headache after a long drive with rear windows open and I think it is due to exhaust backwash.
    Paul Abbott
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  5. #5
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    Probably airflow to keep heat in cockpit down. When racing one should be going fast enough to outrun the exhaust fumes

  6. #6
    Quote Originally Posted by 1QuickS View Post
    Yes, I get a headache after a long drive with rear windows open and I think it is due to exhaust backwash.
    Too slow....
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  7. #7
    Senior Member H-viken's Avatar
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    Would this be prevented by cracking the door windows?
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  8. #8
    I would drive four hours from Chico, CA to Berkeley to go to R-Gruppe meeting and then return four hours to Chico, all interstate driving at 75MPH with door windows down and rear quarters open. Eight hours total driving time and I would know that this resulted in a headache which I attributed to backwash exhaust into the car.

    However, my exhaust is not OEM so there is that.

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    Paul Abbott
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  9. #9
    Senior Member ejboyd5's Avatar
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    Post #3 and post #4 express contradictory opinions relative to exhaust gasses. What are others' experiences?

  10. #10
    Senior Member haul's Avatar
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    in summer you need to have it open…its getting too hot,
    But Paul, I have to ask you..is your fresh air vent flap closing properly, or do you have a constant air flow from the front middle ?

    my flap did not close properly, so a constant air stream is blowing at my forehead..in winter it is even worse, as it is really cold air coming inside..on knowing this, I have either a beanie put on the air inlet, or in summer I flap the sunvisor down, thus the circulation direct to my head is interrupted.

    With the rears and only driver side window open it is nearby impossible to get any exhaust CO fumes into the car…of course the heat exchanger systems are in need to get burned out from time to time to get oil rests burned out and off, but unless any leaks there will nothing come inside …

    I‘d rather see the setup with rears open and window and fresh air vent too much pressured air…the airflow f.i. is different if only one window is open, f.i. only passenger side…

    on my long drives I mostly have the two triangle windows open a bit, not to be annoying from noise, and either one or two rears, depending on weather…

    while driving slow, of course windows come down..

    but still…fresh air flap …constant stream direction to the head-> headache

    just my 2cts

    br
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