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Hey guys,

Can anybody point me to the appropriate thread that I will find this as a 20 minutes search doesnt seem to have helped me.

Who has made some serious Radiator exhaust ducting? Im about to embark on a very large duct build that will direct about 90% of radiator air straight out the hood. Out a 4 inch by 3 foot cutout.

Who here has built this sort of thing, and why dont I see it everywhere?

Dann

Progress pics

from what I've heard from Lotus Elise owners, the heat soak into the cabin can be pretty unpleasant...

Adding the cutout to a low pressure zone on the bonnet is a good plan, nothing new.
http://autospeed.com.au/cms/A_2162/article.html
I'm not sure that I'd force that to be the only exit though.

I dont have a fan or anything. So I neednt worry about the super hot air coming in through my air con.

It will have ducting for the engine bay, there will be storm water pipe that runs straight back from right against the back of the radiator to a hole (the pipe sealed into the hole) through the curved duct part. Fixed? Or am I still not thinking hard enough?

Dann

Not sure why you'd want to do this? You've also got a hot exhaust manifold sitting behind the proposed ducting. What's your thinking here?

Instead of buying a huge radiator, id prefer to try and make it as efficient as possible and try to rid the car of front lift at the same time (I mean help the splitter).

What do you mean regarding the Manifold?

Dann

I was thinking your reason might be related to dealing with excessive heat in the engine bay. Haven't thought too much about aerodynamics so I've nothing to suggest there.

Why?

There are a lot of simpler ways of getting the necessary cooling done, without this. AFAIK the big HP track cars don't need it, so I can't see why you would want/need to pioneer a new route.

On the other hand, if you want to do it because you want to do it, that's fine, go for it.

As Matty says, make sure you have your exit in a low pressure area, search on here as I remember someone did some pressure testing on the front of the car, and make sure that the rest of the engine bay has enough cooling too. I have also seen generic air pressure diagrams showing pressure ditribution over the nose, and the location of the LP area. Since you are going to cut up your bonnet anyway, get a manometer, drill some holes, and you are away!!

IMo because the MX5 world has a huge aftermarket of bolt ons, we have MONSTROUS radiators for a good price. This makes people lazy. the big dollar track ca do have hood vents, they are all in the same place, and all the manometer or pressure differential tests show the same thing, so thats not an issue.

Im doing it because I want to build a downforce producing setup that allows me to use the stock radiator at my chosen HP levels (well past 200atw). SE's have small stock radiators and manage to keep them until pretty high HP level and yes they do have different ducting. It seems to me that here is OZ as opposed to the states everyone just wants to throw money at a shop like mania and bolt everything on. I want to have awesome homemade (free..) cooling that plants the front on the road.
I was hoping on this thread for people to give me reasons why no one does this, I think the answer is because no one in oz would paint their own car matte black and hack up their bonnet and still drive it to work every day. Prove me wrong and give me serious ideas to help me make this work.
Come on.
Dann

Hey Dann,

By the looks of things your building a reroute of the hot air that isn't used by the radiator while hoping to achieve a maximum downforce advantage from the angle of the plating used.

Have you considered adding ducts to your existing hood, NOT headlight cover such as these ducts

http://secure.mckinneycorp.com/AMAZING/items.asp?Cc=NACA&Bc

Also i found the following thread from flyin miata

http://www.flyinmiata.com/projects/CF_hood.asp

They have cut larger hole in the hood to extract the head.

As for more downforce, have you considered the aftermarket splitters for prototypes to make a model off?

Goodluck regardless, if i find anything else ill link it here

Also a DIY option, though i think you would have to brace the part you "bend" because it would need more support under greater movement pressure.

http://forums.subdriven.com/showthread.php?3983223/page1

For some real deal downforce copy Si and his front splitter.

viewtopic.php?f=57&t=40374

I think some people have really missed the point. The car is already ducted in front of the radiator. Ie all of the air that enters the mouth is forced through the radiator, none of it can escape around it.

This duct guides all of the air that is pushed into the radiator, upwards and out the hood.

The change of direction will push the duct down, like a wing, and provide downforce, while the low pressure area on top of the hood will suck the air through the radiator, pulling far more air through it, greatly improving the efficiency and doing the same job as a much larger more expensive radiator.

Dann

So this, but uglier?

http://www.7extrememotorsports.com/lemans/cars/chevrolet-corvette-c6r-06.jpg

Great picture. Exactly.

Dann

It is actually a really great idea even if you have a stock or upgraded radiator.

Keep us updated with the pics with the angles I know we dont have that much room to work with but I'm in the process of fabricating a different short air intake so I should free some room up. What's it like cutting the aluminium hood ..?