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Thread: Driving without Underpan

  1. #1

    Default Driving without Underpan

    I know the rear underpan helps with rigidity However, I have heard of people driving without it to improve cooling.

    My question is...do you think its ok to take my car to the track without the underpan? (beginner class)

    I have heard of others driving over 140mph without the underpan and I will not be going anywhere near that speed.

    Thanks

  2. #2

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    Yes it will be fine, but you may lose downforce.

    Long term the joints on the chassis are getting stressed more (in theory) the underpan does offer additional rigidity, but it may well be surplus to requirement.

  3. #3
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    Hard to be quantitative, but I doubt that any improvement in engine compartment cooling is worth the loss of down force (and the increase in drag).
    Joel

    '67 Lotus Elan S3 DHC (owned since 1970)
    '17 Ford Focus RS

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    The huge rooster tail of water blowing out the diffuser while driving in rain is testament to it and the underbody's effectiveness.
    I feel bad for the people behind me, except when they've been blocking the passing lane of course!

  5. #5
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    I wouldn't worry at all and if your new to track driving you shouldn't be concerning yourself with down force and going 140 mph. I'd get some experience before driving on a track at that speed. 140 on a track is very different than on a highway (it legal on the track), on a highway you almost always have straight road in front of you (and shame on you if you don't) and you can just lift to slow down. To hit 140 on a track you're going to have to be at full throttle for a long part of the straight and then you'll need to brake pretty hard to dump the speed before the inevitable slow speed turn. Don't do that if you are a new driver and want to keep your car in good running order. Go have a blast and forget about the belly pan.

    Jake

    PS; don't let the gas tank get below 1/4 full, at that level or below you can uncover the gas pickup tube and lean out the engine. I personally never let it go below 1/3 full.
    Last edited by JG400; 05-08-2011 at 05:27 PM.

  6. #6
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    Quote Originally Posted by JG400 View Post

    I wouldn't worry at all and if your new to track driving you shouldn't be concerning yourself with down force and going 140 mph. I'd get some experience before driving on a track at that speed.


    PS; don't let the gas tank get below 1/4 full, at that level or below you can uncover the gas pickup tube and lean out the engine. I personally never let it go below 1/3 full.
    Great post Jake, fully agree with you. Wish I'd have started out in "learning mode" as opposed to "140 mph" mode...I put my car through unnecessary stress overdriving it, upsetting the balance especially under braking, trying to shift too fast, etc etc...wish I'd known earlier it's all about smooth...shoulda bought the Spec Miata first, THEN the Noble...way too much power for me as a first-timer...

    I remember one of Derek's posts when he was looking back at his first yr in his Noble. If I recall, he posted that his best time at VIR in the Noble was a 2:25 . Was laughing his ass off at the memory of all that, as he can now do 2:18's in a Spec Miata...and of course now his Noble is a sub-2:00 car with him behind the wheel...

    And yeah, at 1/4 tank in any kind of mid-to-high g corner, she'll start coughing from fuel starvation, absolutely refill!

  7. #7

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    Quote Originally Posted by Zezinho View Post

    I remember one of Derek's posts when he was looking back at his first yr in his Noble. If I recall, he posted that his best time at VIR in the Noble was a 2:25 . Was laughing his ass off at the memory of all that, as he can now do 2:18's in a Spec Miata...and of course now his Noble is a sub-2:00 car with him behind the wheel...

    !
    Gawd! Has anyone thought how embarrassing it would be if there was ever a video posted on U-Tube of an experienced spec-Miata driver thrashing a Noble?? I shudder at the thought.

  8. #8
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    I remember Dean once said that less than 20% of Nobles ever saw a track...

  9. #9

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    Quote Originally Posted by DrDaKine View Post
    Gawd! Has anyone thought how embarrassing it would be if there was ever a video posted on U-Tube of an experienced spec-Miata driver thrashing a Noble?? I shudder at the thought.
    The real funny thing is that as far as I know. More Noble Owners, who have SCCA licenses, are or have raced Spec Miata then any other car. Myself included. What are the odds?

    Spec Miata is very competitive.

    Scott
    Scott Starkey
    2005 Red Noble M400
    #09 Spec Miata / ITA Miata WDC SCCA MARRS

  10. #10
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    Talking

    No underpan? It's kinda like going commando. A little more risk involved, but it's a great feeling of freedom at top speed.

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