door roof wind deflectors
- Thread starter heppy36
- Start date
Tim Kay
Lifetime Supporter
Here's what I did to eliminate the eyebrows installed on the outside. Sorry, I only have pics of the door attachment which may be a bit hard to see but I attached a set of mating slide plates to the interior, one on the door and one on the spider. If you'd like more pics I can shoot them.
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Mike Pass
Supporter
Here are a couple of pics which may help. If you just fit the "eyebrows" then because the top of the door is flat the rubber seals push the door up so when it is shut the edges catch and can scratch and chip the paint. Also at very high speed the car acts like a wing with low pressure over the roof which causes the door tops to lift. It has been known for the plastic type of eyebrows to break off and the door top to be pulled open - very scary! Fairly substantial aluminium ones are available which are better
The best solution even if you use the eyebrows is to use the stainless steel clips on the spider centre and on the door inners which pull the door down and hold it firmly in place. This also helps a lot in keeping the rain out. I have them on my GTD and they do the job well.
Cheers
Mike
The best solution even if you use the eyebrows is to use the stainless steel clips on the spider centre and on the door inners which pull the door down and hold it firmly in place. This also helps a lot in keeping the rain out. I have them on my GTD and they do the job well.
Cheers
Mike
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Caution, the internal stainless steel clips are very close to your head and can / have caused severe lacerations to scalp !
Tim Kay
Lifetime Supporter
....... not when you have roll cage :lol:
Howard Jones
Supporter
Ya mine has those also. I think you need them or the other exterior top capture method. I could see where at higher speeds 70-90MPH air could get under the door and lift it. If you really put your foot on it, it wouldn't take much separation for the door ear to really be damaged of even crack the fiberglass. Really high speed +150 or so and I believe it COULD break off. That's a lot of surface area under the door ear.
Frank is right. They will trim your hair for you. Usually once is enough and you will learn to duck. The top capture method is better I think. But you will need to source the "eyebrows" whereas you can make the clips pretty easily.
Frank is right. They will trim your hair for you. Usually once is enough and you will learn to duck. The top capture method is better I think. But you will need to source the "eyebrows" whereas you can make the clips pretty easily.
Recalling the 24 Hours of Daytona Historic race.....one of the GT40's running at the event had to modify the doors to prevent a "HUGE" (drivers description) hole that was created during the high speeds they were pulling on the banking. He told me he looked up to see a gap of nearly 4-6" being created as the top of the door separated from the spider. They devised a simply solution of making a metal bracket to secure the door for the race. The bracket was placed on the outside. "Not pretty but effective" he added.
They are very easy to make, just need the right profile ( too many poor versions out there )
Mike Pass
Supporter
I got some from Mick Sollis but decided against using them they were u section aluminium about 1.5 mm thick. They are not really wind deflectors as they fit at the central part of the door and not the front edge. Most people call them eyebrows as this describes the shape quite well. I decided not to use them as they will scratch the edge of the door top as it shuts. I guess you could apply a clear plastic film to protect the paint. Without the stainless clips which pull the door down as it shuts onto the sealing rubbers the door edge gets pushed upwards by the seals and the top edge gets scratched by the aluminium. I don't have an issue with the stainless steel clips and think that anyone who doesn't duck their head when shutting the door on GT40 perhaps shouldn't have one.
Because the top of the car is curved the air travelling fast over the top of the car causes a low pressure area over the roof in the same way as an aircraft wing works. This low pressure over the top of the door acts over quite a large area and at high speed results in a large force which needs to be counteracted by some means. To see what I mean try and shut the door when the car is doing 70 mph. You can't because the door is lifted above the roof.
Some years back a friend of mine was doing max speed runs in an SPF which had plastic eyebrows. At 177 mph the force was too much for the plastic eyebrows which broke and the top of the door lifted several inches which was fairly scary. I use the stainless clips and have never had a problem with the door tops lifting but then again I may not be brave enough. Perhaps Glen Mason could comment as he did about 190 mph in his Southern GT which is as good a test as you can get.
Cheers
Mike
Because the top of the car is curved the air travelling fast over the top of the car causes a low pressure area over the roof in the same way as an aircraft wing works. This low pressure over the top of the door acts over quite a large area and at high speed results in a large force which needs to be counteracted by some means. To see what I mean try and shut the door when the car is doing 70 mph. You can't because the door is lifted above the roof.
Some years back a friend of mine was doing max speed runs in an SPF which had plastic eyebrows. At 177 mph the force was too much for the plastic eyebrows which broke and the top of the door lifted several inches which was fairly scary. I use the stainless clips and have never had a problem with the door tops lifting but then again I may not be brave enough. Perhaps Glen Mason could comment as he did about 190 mph in his Southern GT which is as good a test as you can get.
Cheers
Mike
Are there more guidelines available on the exact positioning of the profile onto the roof.
I guess a soft aluminium alloy is used to bend it, is it a U-shaped profile or L-shaped profile ? More details are always welcome
Below you'll find two pics of original NOS eyebrows found on this forum :http://www.gt40s.com/forum/gt40-tech-exterior-interior-ac-trim/25082-eyebrows-needed.html
L shaped steel, as you can see.
I was fortunate enough to had a very close look to P/1078 (Mr Nahum's car) two months ago, and I could notice that the top of the doors have a thin recess the exact shape of the eyebrows, thus allowing a good fit and no rubbing (and the eyebrows could be then set "low profile")...sorry, was mesmerized by this car, didn't even think to use the camera hanging on my chest.
Don't know if that was period correct, but seems a nice and elegant solution to the usual issue.
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Brett James-McCall
Moderator
FWIW, I think Robin Sundt made his eyebrows extend across the front clip to the top of the A pillar to assist with wind noise etc
Brett
Brett
Glenn M
Supporter
Quite right Mike, 192 in fact, and no problem at all with door lift. My car uses the aluminium eyebrows as supplied by Southern GT with, as Mike suggested, a thin strip of helicopter tape to prevent scratching. It's simple and works a treat!
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Hi FRank
what about the other 'these'...the one when taking out the windows ?
Do you know where we can find them ?
Mxmas and HNY to you and Barbara !
Fred
what about the other 'these'...the one when taking out the windows ?
Do you know where we can find them ?
Mxmas and HNY to you and Barbara !
Fred
