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Cedric
Joined: 27 Aug 2004 Posts: 2600 Location: Sweden
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Posted: Sat Feb 12, 2022 10:41 pm Post subject: |
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During my professional life ive come to the conclusion that its better to not do CFD than to do a bad CFD. Since it only confuses and might yield wrong conclusions. But as a learning exercise it could be fun for sure. But in this case we already know what needs to be done more or less for the big gains, especially if you start from an untouched car.
If i remember correctly the 924 has a Cd of 0.36 without the rear wing and 0.34 with the rear wing. I think the CGT had 0.34 aswell despite the wide body, due to the front end, flush windscreen etc.
Side skirts arent guaranteed to improve things, as can be seen in some testing that Simon Mcbeth did in one of the "aero bytes" articles, as most stuff it depends on many many parameters. But they are fairly easy to make though. _________________ 1980 924 Turbo
www.instagram.com/garagecedric/ |
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gegge
Joined: 27 Jul 2007 Posts: 1124 Location: Sweden
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Posted: Wed Feb 16, 2022 6:58 pm Post subject: |
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For a low Cd? Check out the 924 world record car...
https://www.youtube.com/watch?v=Il5uav5bj7I _________________ Carl Fredrik Torkildsen
924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs |
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Juho
Joined: 03 Oct 2018 Posts: 377 Location: Finland
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Posted: Thu Feb 17, 2022 7:29 am Post subject: |
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i want downforce too but boy that front bumper looks nice |
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Fasteddie313
Joined: 29 Sep 2013 Posts: 2596 Location: MI
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Posted: Thu Feb 17, 2022 8:34 pm Post subject: |
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That rear end is SWEEET!!
Love the exhaust out the front fender too.. _________________ 80 Turbo - Slightly Modified |
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Juho
Joined: 03 Oct 2018 Posts: 377 Location: Finland
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Posted: Mon Feb 21, 2022 8:44 pm Post subject: |
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so acquiring data drag could be measured by simple coast test and lift/downforce with monitoring suspension travel. what u think would be easiest way to monitor suspension travel? |
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Cedric
Joined: 27 Aug 2004 Posts: 2600 Location: Sweden
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Posted: Wed Feb 23, 2022 7:04 pm Post subject: |
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Juho wrote: | so acquiring data drag could be measured by simple coast test and lift/downforce with monitoring suspension travel. what u think would be easiest way to monitor suspension travel? |
Have you done coast down before? I think it will be hard to use for small changes , if you cant use very high speeds. Maybe Julians throttle stop technique could be something, especially if it could be used at a slightly higher speed like 120km/h. And you will need a pitot tube for reference pressure and actual speed measurments.
Logging the ride height with potentiometers is common, but you will have to log the signal so you can do some signal processing to make it useful. Maybe check what FSAE teams uses. _________________ 1980 924 Turbo
www.instagram.com/garagecedric/ |
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Juho
Joined: 03 Oct 2018 Posts: 377 Location: Finland
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Juho
Joined: 03 Oct 2018 Posts: 377 Location: Finland
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Posted: Thu Feb 24, 2022 2:19 am Post subject: |
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This what the lap time improvement would be with aggressive aero on track in sweden called Ring Knutstorp, very marginal.... |
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Cedric
Joined: 27 Aug 2004 Posts: 2600 Location: Sweden
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Posted: Thu Feb 24, 2022 2:27 am Post subject: |
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Ive done quite some optimumG on my car, its a decent way of predicting lap time for different type of changes.
I don't think knutstorp is a good place for evaluating Df, since it has pretty much one fast corner. Very very fun track though _________________ 1980 924 Turbo
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Juho
Joined: 03 Oct 2018 Posts: 377 Location: Finland
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Posted: Thu Feb 24, 2022 2:28 am Post subject: |
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I know but these type of tracks we have here though
Power increased and aero increased.
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