cut the leading rectangle and form the rest of the hood up to make a cowl this will create a low pressure region after the hood and keep alot more water out. that is just what i can see though could be wrong. it might take a little heat/hammering to get it to look right but this would be a simple solution

 

This thread makes me want to hack my CF hood... just don't know what and how to do it

 

I think I get what you're saying, and if I do it's the opposite of what needs to happen. The front edge will be slightly raised which will help increase the pressure differential over and under the hood at the opening. Then the rear edge will be pushed down towards the motor a bit to create a scoop to help direct the air through the opening.

 

no so long as there is abit of overlap to the edges the increased velocity should create a low pressure system. This would be like running a scoop to funnel air in but in reverse you beat the hood up in the triangle and stretch the metal to a point of about 2-3 inches above the highest point. you might tig on abit of an extension or part the hood and add abit more aluminum to stretch it easier. This should siphon air though. forgive the paint work Not all of us are as artistic as scot and Adam

 

I understand what you mean. Would look cool to replace the power buldge with something like that. It would be like the Simpson hood.

 

c h a r a c t e r s

 

Ok, did the H thing. Best tool to cut with was the jig saw with fine metal blade. Only problem was the drill holes to get the blade in. After that, the saw cut smooth and clean. Too bad I didn't figure out the "scroll" function of the saw, or I would have only had 1 drill hole instead of 3. The worst part cosmetically is how I tried to grind out the drill holes. I should have left them and gone over with filler. Cut the H, bent the rear flap down, bent the small front flap up. It would look super bad *** once cleaned up.

Obviously I didn't do any prep work to the hood for cosmetics. And it looks 10x worse in the pics than it does in person. I am going to try it out some more, and after I make final adjustments--IF I deam the idea sound (more on that coming)--I will prep it up and try to make it look purdy. I was too eager to try it to clean up the edges.

So on the car it went, and I went off for a drive. I have a typical drive I take after making changes. I always do the same thing. 5 minute warm up, take the same route starting like a granny, go to this end of a dead street, turn around and come out WOT 1-4. Then I drive around a lake... The whole thing is about 15 miles.

Here's my take from watching the laptop as driving, and also going over the datalogs.
My peak IAT after 4 gears at WOT was 4 def F less than yesterday's run from the exact same drive. But what was really interesting was typical IAT. About 10-15 deg F lower. In fact, cruising IAT was appx the same as IAT before driving anywhere. It was 92F before I drove away, and it was 96F when I got back into my driveway. It's usually 110F or so.
Coolant temps were about the same. 203F going to 207F in boost. Hit 211F once briefly. The peak numbers were the same, but it spent much more time at 203F than before. The car seems to like to hold itself at 203F. It has a factory thermostat in it still. Next coolant flush, I have a new thermostat for it.

Next experiment is replacing the turnsignals and seeing what that does. After that, I am going to vent the area over the turbo. I'll do it symmetrically with a matching vent over the intake mani.

Hood installation is easy. So if anyone else in the area wants to try it out, you're welcome to.

 

thanks for experimenting, I may do something similar.

When I was finishing my turbo stuff, I ran over my hood after I set it down in the yard so it's kinda ugly anyway.

 

Damn that sucks about the hood al, hack that beast up.
That drop in IAT is awesome though.
What's next on the venting project?

 

Looks cool man, I might do the same thing on my hood, going to mock it up and see tomorrow.

 

nice i look forward to more results

 

ben- were you running the stock undertray?

 

yes, though it's been "modified" for IC pipes.
I am also going to cut out the hood per your location idea, however I'm only going to remove a smaller area, inside the frame rails only.

 

So Ben, you going to mass produce these if they work?

 

you must be looking at pics of a different hood :gay:

but seriously, if I had another hood I know I would do better. I wouldn't mess with the cut-off disk, and I would use the scroll function on the saw. I would also have placed the vent another 1" towards the back.

 

you should keep the cut out pieces, reattach with a hinge at one end and then connect the other end to a cable (old hood release?). Then we'll have some real time data comparisons. :gay:

 

Actually Rob I was thinking about something more like a big magnet sheet.

Looking at my datalog, my cruise coolant temp hit 200F in a few places. Not constantly or sustained, but I've never seen less than 203F before--though it does like to sustain 203F.

 

I gotta say that coolant temps have never concerned me like oil temps. Even running 203f coolant temp is fine IMO- after all the OE fan thermoswitch doesn't even trigger on until 207f. My reason to vent the hood is primarily for traffic driving (since I don't see elevated temps at speed anyway). If the turbine generated heat is allowed to escape when the car comes to a stop, rather than waiting for the fan to come and starting forcing underhood hot air out, I believe a lot of heat soak can be avoided.

 

My A/C is cold now. I mean *cold*. Boosting around town I felt like Satan frozen in the 7th layer of hell.

 

are you converted to 134a? Did you make any other cuts?
Just wondering how this changed the heat (rise) in traffic? and if it's sufficient to bleed of heat from the turbo too while stopped?