rear sunroof clips and safe speeds
03-31-2010, 12:51 AM
#16
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I'm thinking that the lift would come from precisely the concept of a wing. The flow over the top vs. the flow under the wing creates lift bye pressure differential. And I agree with you. lol
03-31-2010, 12:55 AM
#17
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Next time you are a highway speeds, with the top down. Now tilt the roof up. Now that it's up, sense the pressure. Now crack the windows about 1/4 inch. You'll litterally feel the difference.
03-31-2010, 12:58 AM
#19
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^^^ofcourse the science is something for which I have no training, but if I can fly an airplane, guide a parachute, and make a sniper kill at 1k, I'm guessing that sometimes experience gives ya enough info to be somewhat correct...but I could be wrong. 
03-31-2010, 01:00 AM
#20
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no, I actually mean wing lift. The speed of the air over a wing is faster than the air under. That creates a pressure diff that creates lift...to the best of my knowledge. That's why an airplane can't fly below the stall speed of it's wing.
Last edited by ehall; 03-31-2010 at 01:01 AM. Reason: blow should say BELOW
03-31-2010, 01:29 AM
#21
Bannana Shine
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Are you suggesting that the total airflow over the car would increase in speed when the roof is tilted up, therefore increasing the effective pressure differential between the underbody of the car and upper surfaces?
It's certainly possible, and like I said, I haven't put the car in the wind tunnel. I think it's more likely that the car does not create laminar flow from the trailing edge of the raised panel to the hatch, and this flow separation acts exactly like the spoilers on an aircraft's wing, killing lift. If you look at the shape of a wind with a spoiler deployed, and then the profile of the 968 with the panel tilted up, you might see the similarity.
It's certainly possible, and like I said, I haven't put the car in the wind tunnel. I think it's more likely that the car does not create laminar flow from the trailing edge of the raised panel to the hatch, and this flow separation acts exactly like the spoilers on an aircraft's wing, killing lift. If you look at the shape of a wind with a spoiler deployed, and then the profile of the 968 with the panel tilted up, you might see the similarity.
04-07-2010, 12:24 AM
#22
1st Gear
968 sunroof
Why not just get some replacement gears and fix it properly? I did that four years ago when I first got the 968. I use the sunroof a lot (both the rear vent and removing it entirely) and haven't had any issues.
Clarks has a very detailed writeup. Just follow along and you really can't screw it up; there's nothing complicated about the process at all. Make sure you adjust the slip clutch correctly as per the instructions. It calls for 6 ft-lbs or something; I know mine was way tighter than that when I started; and that's what strips out the gears.
Clarks has a very detailed writeup. Just follow along and you really can't screw it up; there's nothing complicated about the process at all. Make sure you adjust the slip clutch correctly as per the instructions. It calls for 6 ft-lbs or something; I know mine was way tighter than that when I started; and that's what strips out the gears.
04-07-2010, 12:32 AM
#23
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jaro, welcome. go to www.clarks-garage.com
There is a writeup and DIY for your sunroof problem. It should be just the thing you need. For new gears, if you need them, or anything else, go to www.paragon-products.com. look under 968 body mechanical.
Again, welcome. Take some pics of the 968 and show it off!
There is a writeup and DIY for your sunroof problem. It should be just the thing you need. For new gears, if you need them, or anything else, go to www.paragon-products.com. look under 968 body mechanical.
Again, welcome. Take some pics of the 968 and show it off!
04-07-2010, 12:50 AM
#24
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Are you suggesting that the total airflow over the car would increase in speed when the roof is tilted up, therefore increasing the effective pressure differential between the underbody of the car and upper surfaces?
It's certainly possible, and like I said, I haven't put the car in the wind tunnel. I think it's more likely that the car does not create laminar flow from the trailing edge of the raised panel to the hatch, and this flow separation acts exactly like the spoilers on an aircraft's wing, killing lift. If you look at the shape of a wind with a spoiler deployed, and then the profile of the 968 with the panel tilted up, you might see the similarity.
It's certainly possible, and like I said, I haven't put the car in the wind tunnel. I think it's more likely that the car does not create laminar flow from the trailing edge of the raised panel to the hatch, and this flow separation acts exactly like the spoilers on an aircraft's wing, killing lift. If you look at the shape of a wind with a spoiler deployed, and then the profile of the 968 with the panel tilted up, you might see the similarity.
Are you saying that you think that the raised panel creates a stall, by spoiling the flow? If so, why is the suction so strong from inside the cabin toward the outlet area of the raised roof panel?
I would have thought that the suction was caused as a dirrect effect of the laminar flow over the roof, pulling the air from the cabin.
Like I said, I'm purely speculating, and trying to figure it out.
01-25-2012, 01:42 AM
#25
My sunroof flew off the other day. I couldn't find the front plastic clips. Does anybody have a part number for these or know of where I can get them? Doesnt look like Pelican has them.
