Carbon Fibre Roof Vent

[superdave]

Hi everyone, one of our members has asked me about roof vents for an esprit, similar to the GT and rally cars. I have made some enquiries and my carbon fibre guy already makes them for Ford, Subaru and Mitsubishi. It comes with outer, inner and weather proof section. These are made from carbon fibre. I haven't seen these on the above listed cars or whether they would retro fit an esprit. Iam going tommorrow to check it out. This should give more air into the cabin and could be an addition to the CF roofs that I have done in the past. It has controls for driver and passenger inside.
Wouldn't have thought it would generate much interest but you never know. I will fit it into my prototype No.2 CF roof. This way there is nothing lost if all goes wrong.
I already have two people interested. Let me know your opinions/ constructive critisms.


Cheers,



Dave Walters

[kylie]

Dave I think its an excellent idea, wow they would be the talk at club track day! I hope you get enough to produce some.

[ErnestM]

Pictures? (even of the ones on other vehicles)

ErnestM

[superdave]

Ernest, if I get one to sit right when I visit my CF guy then I will take a few pictures.
Kylie, thanks. It's only something I was thinking for myself but any interest would be welcome. My car doesn't have air con and the face blowers just blow cold air to your knees at the best of times. The roof mounted ones should work a treat.
As I have one of these CF roofs, it makes sense for me to hack into mine.
It would be a shame for anyone to cut into their composite roof.
The best idea would be to mould a complete new roof with the air vent as one piece but this would be costly as a one off.
I could have this roof with a vent and another CF plain roof and interchange as my mood fancies.


Cheers,



Dave Walters

[kylie]

Some ace pics of a vent on a Subaru in the attached site. www.swrt.com/90500.html
Looks kinda big though, something a little smaller perhaps? I wonder how this would affect the air flow over the car.....mm
Looking forward to any other ideas.

[ErnestM]

To cut down on drag, couldn't you just fair in a couple of NACA style ducts in the roof panel?

www.quickcar.net/cooling/cp_nacaduct.html

Picture of faired in NACA ducts on a Porsche bit:



This would reduce drag and might even compress the air a bit and as we all know, compressed air is cooler air...

ErnestM

[h2dca]

Superdave, further to a previous note regarding a split roof for ease of storage I have not had much time to review this but I am interested in a CF roof from your guy if possible (With/without vents)
I will drop a note direct
Regards
Hamish

[superdave]

Thanks Hamish, I do remember you previous e-mails. look forward to hearing from you again.
My e-mail address is [e-mail]

Dave Walters

h2dca said:

Superdave, further to a previous note regarding a split roof for ease of storage I have not had much time to review this but I am interested in a CF roof from your guy if possible (With/without vents) I will drop a note direct Regards Hamish

[superdave]

The NACA style duct is the original idea I came up with. Problem is that it requires a seperate mould and without the interest, it would be too expensive as a one off.
PNM will be building a race car soon and they want this style of roof to send ducts into the top of the engine. This is the ideal time to take the duct idea to the next level with PNM. It won't be for a long time yet, I reckon about a year.
The idea of a raised vent is that you can plant it on. It's only an experiment at the moment and may look like a pig's ear on an Esprit.
This is the beauty of owning an Steven's shape car is that I like to play with different ideas. If i'd have bought a newer S4s or V8 then none of the projects that I have done would have even been considered.
The carbon fibre roof has been a bigger sucess than I thought. Here's one happy customer from Japan, my first overseas order.

http://community.webshots.com/scripts/editPhotos.fcgi?action=showMyPhoto&albumID=110341083&photoID=152899281&security=aINLUi

[fflyingdog]

I thought that if you compressed a gas it got hotter not colder..............just a thought? You could also mould an exit venturi to extract the warm air out of the cabin,but i suppose you may have a problem of noise...

[igreenrover]

I think that Ernest is referring to the expansion of a gas that has already been compressed? Remember Pv=MRT

However, if you are compressing air this way then you must also be increasing overall drag.

Gareth

[ErnestM]

igreenrover said:

I think that Ernest is referring to the expansion of a gas that has already been compressed? Remember Pv=MRT However, if you are compressing air this way then you must also be increasing overall drag. Gareth

- would probably kick in some extra drag - however probably not as much as a huge box sitting on top of the panel...

ErnestM

[fflyingdog]

Ah Bernoulli's Theorem .........pressure and velocity interact static pressure + dynamic pressure = total pressure = constant static pressure + 1/2 x density .........thought i had forgot all about that in training........!

[igreenrover]

Ernest, I can’t argue with that.
The huge box is definitely the drag king!

[greezmunky]

A properly designed naca duct give almost zero drag. My friends shop builds them to NASA's spec and has great results.

www.ppi-tuning.de/naca_en.htm

I was planning on replacing the stock air intake "hole" with a real naca duct at some point in the future.

[superdave]

Hi guys, I have been thinking about these vents further. The NACA ducts used as an air intake is fine but as an air feed to the cabin would be a nightmare as it will piss in water every time it rains.
Apparently this bolt on one has it's own weather bar and Iam led to believe it may have a drain hole at the rear.

[fflyingdog]

Good point !