Made this today. it turned out good i got some pix of how i did it.

First we had to mark out on the hood where we were going to put it.


Then we covered up the car so that we did not get sparks on the paint.


Then we cut out the hole out for the vent.


Then we painted the cut steal so that it would not rust.


Then put the vent on and this is how it looks now.

looks a bit small, but at least its not just a POS vent stuck on to the bonnet.

but remember, where air can go...so can water

with a vent that small and how it sits in the bonnet, i dont think you will get alot of air forced in it, just over it

not bad. looks pretty good and + 400hp

angle grinder FTW! hehe does it suck much? looks pretty good, nice subtle lil mod

I don't see that doing anything...

perhaps if it had a scoop then maybe yes.

and u get +100 street cred

What happens when it rains =\

omgz you destroyed it

why?

to each is own, i guess

that would make absolutely no difference to engine power output.

looks ok i spose..

Not bad for a home job - least you were smart and protected the paint and underbonnet.

simple and effective... maybe could look better tho but each to his own.

If the pod (or wateva is under the bonnet) is air tight so that only air comes in through that vent i can see it doing alot of good.

It may not do a great deal, but for the minimal amount of work, it looks nice.

i think you had the right idea and the function is there, however i think there is room to improve...

i think a better idea is a large vent towards the back of the bonnet to vent hot air out instead of trying to feed heaps of air in.

edit: people dont do this kind of thing enough. people should take a leaf out of your book and start posting up more DIY mods.

http://www.boostcruising.com/forums/index.php?showforum=174

dosent get much use though...most of those are fairly old

poor bonnet..

i think it would have to be towards the front of the bonnet near the radiator (as with the lotus's ect-). From what i understand there is a high pressure area at the back of the bonnet caused by air curling back at the windsheild.

on that note we are spaceing the bonnet tomoro so that the hot air rushs out the side. i have played with hoods befor this is a pix of one of them. The heat just pissed out of this engine never got to hot. But did not wont watter to get in it so i am goting to put perspects in it so that it will be all show.

i thought i put this on here o well i will put in here rather than starting a new thread..
These are actually called NACA ducts or vents here are some of the aerodynamic advantages of these
http://www.wisil.recumbents.com/wisil/nacaduct/naca-duct.htm
http://naca.larc.nasa.gov/

Thought I would let you guys know about my latest project I'm putting speed holes in my bonnet .
These are some of the materials I've used so far, fibre glass resin, fibre glass matting, hardener to set the resin, scissors and heaps of small paint brushes.


This is the sort of shape I was after but more flush looking.

First off I made a mould of the shape I wanted using thin sheet metal.


Once the mould was made I used aluminium foil as a base sheet which I covered in vaseline to stop the resin from sticking I also did the same to the mould.


What you would normally do is put one layer of fibre glass matting and cover that in resin waiting for it to harden before putting the next layer, but because I'm impatient I put on three layers and waited for that to dry. You should do it one layer at a time and wait in between to prevent air bubbles forming and wrecking the finished product. I added 6 layers in total so I only had to do it twice.


I've also added extra fibre glass around the sides which will be attached to the bonnet from the underneath, because I knew that these areas will be the ones needing the most support.

At the moment I'm up to the stage of modifying the bonnet, I've cut out the area where the vent will be added and have cleaned the surrounding area in preparation. I have also shaped the outer edge of the mould to fit in the hole I've cut.


The next step will be fibre glassing the vent to the bonnet from the underside and then be using a little bit of bog to fill and smooth all the areas to make a flush and clean area for the final step of painting.



OK this is what i was up today
i cut out the 2nd hole
i grinded some paint away near the 2 holes (so the resin sticks better)
i shaped the 2nd vent
taped up the vents
1 because the tape holds it there
2 becasue the tape stops the resin from coming on the top side. (so it should be smooth when i take the tape off)

here you can see the tape and all i do is run fiberglass matt over the tape to join the vent to the hood.

and it glassed

and the big hole that has to be filled.

this is the hole filled


I didn't really have the right kind of environment at home to finish them off anymore and basically this is the only way I have been shown how to do this kind of thing. I just figured at the time it would be easier to attach them to the bonnet and have a solid area that was bigger and more stable for me to work with. I mainly used the bog to really get the finished shape I wanted and to smooth out the area for painting.

This is the first layer of bog I've sanded it back and shaped the area a bit more and will add one more layer just to even it out and smooth the area completly.

looking good at last....
i primed it today and looks heaps better.



this is just primer on the bits that were back to bear metal next week it will get hi-filled


Got hi-fill/primer yesterday just have to leave it for a week to "bake" or dry up.
then will wet rub and reddy for paint......

the hood is looking at not getting paint any time soon as hair line cracks have formed were the fiberglass joined metal...
I'm glad i have left it unpainted this long or the cracks would have been on the top of the paint.

To fix the problem i have to get the di-grinder out and cut it back to were metal meets fiberglass and bog it as the fine bog i will use will be flexible so in theory there should be no cracks in the long run...

metal=flex
fiberglass=no flex,
when you close the hood it flexes a lot it might not look it but it dose.
so when all the hood has moved flexed the bits that cant flex with it (the fiberglass) will brake away from the stuff that can move/flex

those naca vents looks pretty good
well done.

have u painted it yet?? has it cracked or not?

no still no paint as i have not fixed the cracks yet...

cool little mods. the naca vents looks like it may take a alot o fiddling around compared to the firsdt one

@ the first vent. Do you recon it could look good with one on the other side as well?

i rekon the vent on the first one shud hav been bigger, but thats just me.

but it looks good as tho, im goin to do somethin similar, cheers for the idea!

legend

The NACA ducts turned out OK in the end. I was cringing near the start of that job, but seems to have achieved a good result.
Did you resolve the cracks and get it all painted?
If so, got any pics?

Looks nice... dunno how much air you will get in tho.