Effectiveness of wings and front spoilers....
11-02-2001, 07:16 PM
#31
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You could easily use some strain-gauge type meausurement devices and measure deflection in that manner.
Planes receive lift in a couple of ways- The first is just the blunt force of a flat object being pushed into the wind. The second of course is the air foil aerodynamics.
On a Porsche, one would assume an upside wing design in order to create areas of lower pressure below the wing- unless they were using the blunt force method of just hanging something out there in wind at a shallow angle. I assume the latter, since it might be difficult to achieve the "upside lift" with the body of the car right under it, which would disrupt the airflows from joining back at the trailing edge.
My guess is that they were using the blunt force idea to counteract lift.
When landing planes, there is a very noticable high pressure cushion call "ground effect" that is in play about 2x the wingspan distance to the ground. Its pretty asy to bounce a small plane off it. You can think of it as a high pressure air trapped between the underside of the wings and the ground surface.
I've often wondered if the undertrays on a 964 might help generate that sort of ground effect which would seem to detract from handling.
Planes receive lift in a couple of ways- The first is just the blunt force of a flat object being pushed into the wind. The second of course is the air foil aerodynamics.
On a Porsche, one would assume an upside wing design in order to create areas of lower pressure below the wing- unless they were using the blunt force method of just hanging something out there in wind at a shallow angle. I assume the latter, since it might be difficult to achieve the "upside lift" with the body of the car right under it, which would disrupt the airflows from joining back at the trailing edge.
My guess is that they were using the blunt force idea to counteract lift.
When landing planes, there is a very noticable high pressure cushion call "ground effect" that is in play about 2x the wingspan distance to the ground. Its pretty asy to bounce a small plane off it. You can think of it as a high pressure air trapped between the underside of the wings and the ground surface.
I've often wondered if the undertrays on a 964 might help generate that sort of ground effect which would seem to detract from handling.
11-02-2001, 08:25 PM
#32
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I've often wondered if the undertrays on a 964 might help generate that sort of ground effect which would seem to detract from handling.
This is hopw ground effects on Formula cars work, people always like the concept of an Indy car being able to drive upside down at 220+mph because the undertrays create som much downforce.The gas in the tank thing is a whole seperate argument. you are now adding 120 lbs worth of inertia to your car, very bad. Also it will adversly effect your handling because your suspension is now having to contral that weight while the car is moving over bumpy surfaces. "weight"force from aerodynamic devices is way different than weight mass created by filling your trunk with bowling ***** for more front grip.
Just my couple of cents thrown in.
11-02-2001, 09:33 PM
#33
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According to some answers on this string of replies I guess I'm happy to be alive. Living near Germany I have had the plasure of taking my `88 Carrera to the autobahn and taking it to 153mph at a bare straight(!) strip. The car is equipped with chin spoiler only. Damn that was fast, and I can add that I maintained stearability during soft road bends at almost 140mph. The only thing that makes me scare me pants at these speeds are the dangers of the unforeseen, imagine an animal jumping out in front of you at such speed. That´s much more of a concern than spoilers or not I think.... because you will not make quick manouvering at such speeds anyway, right?
From Denmark, Europe in the middle of the night.
PS. Very nice example, that 73´ with the 964 spoiler, well done!
Peter `88 Carrera coupé.
From Denmark, Europe in the middle of the night.
PS. Very nice example, that 73´ with the 964 spoiler, well done!
Peter `88 Carrera coupé.
11-03-2001, 10:45 PM
#34
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Hello
The reason for the spoilers is high speed driving and racing. If you doo neither you don´t need them and if you never had been at speed with different cars you are to virginale to realize carspecific speedlimits
Some ten years ago I had my first drive over 180 mph ( Ruf BTR ) and it was hard work. Impossible to keep the speed in slight curves or uneven pavement ( german highways get uneven at 180 mph ) some 5 years later a 928 GTS at a bit lower topspeed made it feel like average driving and last year a testdrive with a GT3 showed 180 mph in a similar way. I know that 996 Turbo drivers even don´t get nervous at 180+.
It is a pure power requesting thing to punch a 180 mph hole into the air but it is a thing from areodynamic and suspension to make it "safe" and controlable.
The hary feeling is depemding on the drivers. I always have a hairy feeling at higher speeds even cruising with the most modern machine. It is just the respect to have a high speed impact and the danger to tip toe the tires have someting shreed into them. This always keeps some tension and the reflexes are lurking but I remeber the time when I used to drift at 100 mph on the narrower circled highwaycurves ( Leonberg or Aichelberg was the favorite but they redesigned it to a flat out corners. Last resorts will go in the next years ).
Somehow I don´t miss it but on the other side modern cars don´t show any limits and need not to much basic driving skill. They just need cold blood ( or sensless stupidity ? ) and a heavy foot.
I don´t like to get driven. And i always will dail the speed depending on my concentration and skill and so i have no problem to idle down the highway behind the 55mph trucks even siting in a car that idles at 50 mph in 6th gear.
My opinion is that the safety device in a car is the driver and his "lower sensivity".
( hell some maybe call it brain but the reflex is faster then thinking, you need your brain to keep ahead from the traffic and your but drives the car )
Aerodynamics will add speed and make speed handle easier but they are not realy saefty devices. They just push the limit to come in trouble...
Grüsse
BTW: http://www.pelicanparts.com/ultimate...ML/010881.html
The reason for the spoilers is high speed driving and racing. If you doo neither you don´t need them and if you never had been at speed with different cars you are to virginale to realize carspecific speedlimits
Some ten years ago I had my first drive over 180 mph ( Ruf BTR ) and it was hard work. Impossible to keep the speed in slight curves or uneven pavement ( german highways get uneven at 180 mph ) some 5 years later a 928 GTS at a bit lower topspeed made it feel like average driving and last year a testdrive with a GT3 showed 180 mph in a similar way. I know that 996 Turbo drivers even don´t get nervous at 180+.
It is a pure power requesting thing to punch a 180 mph hole into the air but it is a thing from areodynamic and suspension to make it "safe" and controlable.
The hary feeling is depemding on the drivers. I always have a hairy feeling at higher speeds even cruising with the most modern machine. It is just the respect to have a high speed impact and the danger to tip toe the tires have someting shreed into them. This always keeps some tension and the reflexes are lurking but I remeber the time when I used to drift at 100 mph on the narrower circled highwaycurves ( Leonberg or Aichelberg was the favorite but they redesigned it to a flat out corners. Last resorts will go in the next years ).
Somehow I don´t miss it but on the other side modern cars don´t show any limits and need not to much basic driving skill. They just need cold blood ( or sensless stupidity ? ) and a heavy foot.
I don´t like to get driven. And i always will dail the speed depending on my concentration and skill and so i have no problem to idle down the highway behind the 55mph trucks even siting in a car that idles at 50 mph in 6th gear.
My opinion is that the safety device in a car is the driver and his "lower sensivity".
( hell some maybe call it brain but the reflex is faster then thinking, you need your brain to keep ahead from the traffic and your but drives the car )
Aerodynamics will add speed and make speed handle easier but they are not realy saefty devices. They just push the limit to come in trouble...
Grüsse
BTW: http://www.pelicanparts.com/ultimate...ML/010881.html
11-04-2001, 03:38 AM
#35
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Hello
Just some links about basics:
http://www.carsofindia.com/content/t...ch/goflow.html http://www.wisil.recumbents.com/wisi...ero_review.htm http://www.insightcentral.net/enaero.html
Just some links about basics:
http://www.carsofindia.com/content/t...ch/goflow.html http://www.wisil.recumbents.com/wisi...ero_review.htm http://www.insightcentral.net/enaero.html
11-04-2001, 10:35 AM
#36
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To summarize Roland's excellent post: if you feel uncomfortable driving at speed the way the vehicle is configured, don't go that fast.
I know I can probably do 120mph in my girlfriend's Mazda Tribute (V6) but I get an uneasy feeling in my gut at about 85mph. In the Porsche I don't get that feeling until I'm well over 130mph and then it's more of a concern of road conditions than vehicle control.
I don't think twice about accelerating to 100mph in the 911 to get around a vehicle or maneuver through traffic. In the Mazda, I drive at the same speed as traffic and don't change lanes unless I need too.
Don't get me wrong, I don't race during rush hour but if I'm stuck behind someone doing 60mph in the fast lane and I see a big openning, I make a leap for it.
-Eric
I know I can probably do 120mph in my girlfriend's Mazda Tribute (V6) but I get an uneasy feeling in my gut at about 85mph. In the Porsche I don't get that feeling until I'm well over 130mph and then it's more of a concern of road conditions than vehicle control.
I don't think twice about accelerating to 100mph in the 911 to get around a vehicle or maneuver through traffic. In the Mazda, I drive at the same speed as traffic and don't change lanes unless I need too.
Don't get me wrong, I don't race during rush hour but if I'm stuck behind someone doing 60mph in the fast lane and I see a big openning, I make a leap for it.
-Eric
