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How much downforce does stock 991 spoiler produce?

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Old 05-06-2017, 10:43 PM
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shivt1988
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Default How much downforce does stock 991 spoiler produce?


How much downforce does the stock adjustable spoiler develop at speeds of 75 mph or greater?
Old 05-06-2017, 10:44 PM
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STG
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Enough to keep you out of trouble at higher speeds.
Old 05-06-2017, 10:52 PM
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StormRune
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One thing I don't think some realize is that it isn't just about the downforce, it is probably more important that it prevents lift. Without it, the lift you would get is what really messes you up. It would be interesting to know how much lift you'd get without it... even if the total downforce with it is only a few pounds.
Old 05-06-2017, 10:54 PM
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Needsdecaf
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Originally Posted by StormRune
One thing I don't think some realize is that it isn't just about the downforce, it is probably more important that it prevents lift. Without it, the lift you would get is what really messes you up. It would be interesting to know how much lift you'd get without it... even if the total downforce with it is only a few pounds.
This.
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Old 05-06-2017, 11:19 PM
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STG
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This guy is in the stuck up club.

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Old 05-07-2017, 12:46 AM
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shivt1988
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But I wouldn't want to be this guy.
Old 05-07-2017, 02:42 AM
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Ed911.2
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Without it, the lift you would get is what really messes you up
So true.

I remember when the Audi TT first came out there was a rash of cars losing control on the autobahns, some of them virtually getting airborne. A rear spoiler and suspension mods cured it but when you look at the original car profile, it’s not surprising as it’s very close to a high-lift wing section...
Old 05-07-2017, 08:30 AM
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Pavegeno928
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Enough to feel stable at 196 mph/315 kph on A8 from Munich to Stuttgart last year--It's science (from Anchorman).
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Old 05-07-2017, 11:14 AM
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seattle_sun
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Spoiler reduces lift, rear wing increases downforce.

Old 05-07-2017, 12:06 PM
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Hurricane
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Originally Posted by seattle_sun
Spoiler reduces lift, rear wing increases downforce.




Old 05-07-2017, 12:23 PM
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Yard Dog
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Originally Posted by STG
This guy is in the stuck up club.

Attachment 1162745
If your spoiler remains up for more than four hours while parked, seek immediate medical attention.
Old 05-07-2017, 12:24 PM
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Dennis C
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According to Porsche, the aero on the turbo produces 150 kilograms of downforce at top speed. This is about 330.6 lbs.

I haven't seen a number published for the other models.
Old 05-07-2017, 02:47 PM
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96redLT4
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Originally Posted by STG
This guy is in the stuck up club.

Attachment 1162745
Actually, I think that is a really good looking GTS!

J
Old 05-07-2017, 10:19 PM
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Churchill
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At legal-ish highway speeds, the effect of the tail on a 991 is negligible. It's sort of like PSE overrun flatulence. It's a "hey, look at me" feature.

The stat on the '73RS ducktail is that at 152 mph rear lift was 93 lb. with ducktail, 320 lb. with standard decklid. That's not bad, but if the number is similar for a 991 (which it should be) we're talking about a couple hundred pounds less lift at 150MPH on a car that weighs 3,200 pounds. In other words, under 100MPH there is no useful difference.

Old 05-07-2017, 10:58 PM
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cug
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Originally Posted by Churchill
At legal-ish highway speeds, the effect of the tail on a 991 is negligible.
Be aware that there is at least one country (where your car actually comes from) where max speed of even a Turbo S is perfectly legal on some public roads. Discounting them as as show off is kind of ignorant.


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