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Aerodynamic musings

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Old 04-11-2008, 09:38 AM   #16
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Originally Posted by TB993tt View Post
I always observe local speed limits
that would be observe as in "look at" or "view" rather than "obey"
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Old 04-11-2008, 11:57 AM   #17
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Yup we are all total geeks here. But you may be our King!
By the way, why haven't you shaved off your headlight washers yet?
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Old 04-11-2008, 11:58 AM   #18
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By the way, why haven't you shaved off your headlight washers yet?
I have been eyeing them venomously
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Old 04-11-2008, 02:21 PM   #19
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Yup we are all total geeks here. But you may be our King!
Nah, Toby's no geek. He may be obsessive but he also makes good on many of his obsessions and "threats" so that transforms him from anorak to hard-core enthusiast, at least in my eyes.
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Old 04-11-2008, 02:30 PM   #20
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I have read that this rain gutters removal will help Cd by 3%,
so Cd is lowered from 0.34 to 0.33. But it helps even more because Cd x A is main factor in wind resistance and that A (frontal area) will be also lower.
Edited: I calculated that this rain gutters removal will give you 15 horsepowers at max. speed "for free"

But how much this special windscreen mod helps Cd?
It goes 10 cm far from front edge than normal. Can anyone calculate that effect? Jean?

Last edited by Jussi; 04-11-2008 at 06:01 PM.
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Old 04-11-2008, 03:07 PM   #21
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TB993TT, where did you source that lower front bumper/splitter?
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Old 04-11-2008, 04:21 PM   #22
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Melman
The CGT has a much HIGHER Cd than the 993tt you know
Shows how much I know. I'm sure what ever you go with, it will still be a masterpiece. Good luck
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Old 04-12-2008, 01:30 AM   #23
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Toby,
The A pillar shields are worth 5 mph at 185+ according to my good friends that ran a Daytona.
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Old 04-13-2008, 07:49 PM   #24
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Group Buy anyone?
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Old 04-13-2008, 08:25 PM   #25
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Toby keep your car the way is is and buy a GT3 RS and start the mods!!!!
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Old 04-14-2008, 02:29 AM   #26
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Group Buy anyone?
I can sell my RUF A pillar shields because I removed them when I shaved Rain gutters.. PM if you are interested to buy..
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Old 04-14-2008, 02:41 AM   #27
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PM Sent!

Simon.
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Old 04-16-2008, 10:13 AM   #28
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Courtesy of the late great Paul Frere:



So basically factory stock airflow through the front spoiler which allows air to expell just in fron of the front wheels was actually measured in the wind tunnel to improve drag - clever stuff !

My Geek question for today is: (Scott -look away )

Those brake cooling inlets which a lot of us have in place of the stock fog light unit, if they are not "wired in" to be functional (ie do not have all the piping to direct air through the spoiler onto the brakes) and the air just sort of enters the inlets and "splats" into whatever is behind there, do we think that:

1) This will aid the above Frere description by producing even more pressure within the spoiler internals at speed forcing air out in front of the front wheels at a greater (more drag beneficial) speed ?

2) The inlet holes just act as a "drag point" and we are better off drag wise having the fog lamps in place.

3) Increased Drag is irrelevant because the inlets just look sooo cool out cruisin'
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Old 04-16-2008, 12:30 PM   #29
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Can't look away.
You mean people actually have front ducts that are not routed to the brakes?!
I love reading Frere.
I guess it would depend if there is anything to be gained by having extra pressure within the spoiler. There may be a point where extra pressure on the inlet side creates little or no extra volume on the outlet side. If the outlet air's main beneficial purpose is the evacuation of the still air in front of the wheel, is there a benefit to having it done faster?
I would guess the answer is 2) & 3) .
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Old 04-16-2008, 12:40 PM   #30
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Quote:
Originally Posted by ScottMellor View Post
Can't look away.
You mean people actually have front ducts that are not routed to the brakes?!
Mine used to have the proper ducting but I was told it wasn't compatible with the big front oil coolers now in situ - or were they just being lazy ?

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I love reading Frere.
For Porsche anoraks he was THE man, had a unique access to all sorts of factory data - still he had a good "innings"

Quote:
Originally Posted by ScottMellor View Post
I guess it would depend if there is anything to be gained by having extra pressure within the spoiler. There may be a point where extra pressure on the inlet side creates little or no extra volume on the outlet side. If the outlet air's main beneficial purpose is the evacuation of the still air in front of the wheel, is there a benefit to having it done faster?
I would guess the answer is 2) & 3) .
I prefer the extra pressure = extra "dynamic screening" argument but think you may be right.......
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