|
|
|
|
| Author |
|
|
Black and Blue
Join Date: Jul 2000
Location: Austin, TX USA - Ya'll
Posts: 2,552
|
Upright Windshield Drag?
after looking at the pre-996 cars, its pretty apparent that the windshield angle was reduced significantly with the 996. I have read multiple threads about aircooled cars, especially the early cars, simply not having the aerodynamics to hit top speeds like the newer ones.
how much of a difference does the angle of the windshield make? here is a pic to illustrate (ganked from rennlist) as always, any commments are appreciated...
__________________
Kemo 1978 911 SC Non-Sunroof Coupe, two tone Primer Black and SWEPCO Blue, Currently serving as a Track Whore 1981 911 SC Sunroof Coupe, Pacific Blue Project, Future Daily Driver |
||
10-16-2006, 10:36 AM
|
|
|
Black and Blue
Join Date: Jul 2000
Location: Austin, TX USA - Ya'll
Posts: 2,552
|
sorry...i didnt post pic right...
__________________
Kemo 1978 911 SC Non-Sunroof Coupe, two tone Primer Black and SWEPCO Blue, Currently serving as a Track Whore 1981 911 SC Sunroof Coupe, Pacific Blue Project, Future Daily Driver |
||
|
10-16-2006, 10:38 AM
|
|
|
Registered
|
With proper massaging, the pre-996 cars could top 200mph (Ruf Yellowbird, for example). Apparently, the rain gutter is a major source of aerodynamic disturbance.
|
||
|
10-16-2006, 10:41 AM
|
|
|
Registered
Join Date: Nov 2004
Location: Greater Metropolitan Nimrod, Oregun
Posts: 10,040
|
I doubt the windshield angle effect can be partitioned from other changes made on the cars - at least, by us.
You might look up the Cd for each car and compare those.
__________________
"A man with his priorities so far out of whack doesn't deserve such a fine automobile." - Ferris Bueller's Day Off Last edited by randywebb; 10-16-2006 at 02:23 PM.. |
||
|
10-16-2006, 11:27 AM
|
|
|
Back in the saddle again
Join Date: Oct 2001
Location: Central TX west of Houston
Posts: 55,977
|
I don't think the windshield angle is a major problem. I think the flush (or not) fit of the windshield as well as the rain gutters is a much bigger problem as well as the bumpers and under body. I think before the windshield is addressed there are probably several places that improvements can be made.
__________________
Steve '08 Boxster RS60 Spyder #0099/1960 - never named a car before, but this is Charlotte. '88 targa  SOLD 2004 - gone but not forgotten
|
||
|
10-16-2006, 12:02 PM
|
|
|
Registered
Join Date: Aug 2002
Location: Galivants Ferry, SC
Posts: 10,550
|
...all true statements so far...
plus.... The top speed is a function of drag...and drag ( total drag) is a factor related to the Cd ( drag coefficient) x frontal area ( think: projector image of the front view of the car against a screen, in square feet or square meters). The frontal area would likely be very much the same for the two cars, but the Cd was as high as 0.39-0.42 for the mid-80's Carrera's...and I think the later cars got down to the low 0.3 range...maybe even 0.29. This is a big difference and is influenced more by the many details ( lack of drip rails, flush windows, underbody aero work, profile shape of the car itself, etc)...than the effects of the upright winshield, as counter-intuitive as this may seem. - Wil
__________________
Wil Ferch 85 Carrera ( gone, but not forgotten ) Last edited by Wil Ferch; 10-16-2006 at 01:06 PM.. |
||
|
10-16-2006, 12:10 PM
|
|
|
|
Registered
Join Date: Feb 2003
Location: chicago
Posts: 1,077
|
I think Jack should hook up an adjustable angle windshield and test different settings with the ride height sensors to see what effect the settings have on lap times.
__________________
BMW 128i 73 rsr clone - sold 68 912 project to become 911r (almost done!) |
||
|
10-16-2006, 12:17 PM
|
|
1971 Porsche 911E
