Here's a an underhood external air source for NAs. There's actually space behind the plastic bumper support up front that can be separated from the mounth and channeled up and over (or around) the rad, to provide outside air for the intake. Of course this adds pressure to the other side of the rad and takes incoming air away from that which would normally go through the mouth - but it's the net result that counts.

Arrow shows incoming air traveling in behind bumper support. Red area (top view) represents the divider/panel to keep both passages separate.

 

Thats the concept behind the radiator area covers/shrouds made by companies like Cusco and stuff. Although, it looks like yours takes into account air that might escape bumper cover and not just the radiator top.

+1 for DIY

 

some of have hood latches and horns there

 

I blocked mine to decrease the pressure behind the radiator; hopefully making up for the naca duct...

makes a handy tool tray as well.

 

You can move the horn and build around the latch (like I did for the airbag sensor) - the latch was in the way of the oil cooler and lines. Horn is under my driver's side headlight. When I go to the bigger IC, I'll probably have change this to reposition the cooler- sealing off the entire area. Even then a ducting could be fab'd to channel some air from that source to an airbox.

 

the NB has that panel built into the bumper cover itself. more or less.

maybe this weekend I'll start my ducting plan...

 

That's exactly what I was thinking Rob. maybe a 1-2" tube from that area to the filter.

 

Just went out and looked at the area under the driver's side headlight. I can't see any reason not to drill a 3" hole through that sheet metal. It's on the outside of the frame rail and definitely a good source of outside air for the turbo to pull from. Anybody know what the air pressure looks like in the fender well/nose area? I'm thinking that static would be preferred as not to create high pressure on the engine side of the rad. Thoughts?

 

that coupled with a cold-air box and it wouldn't really matter.

 

:ROFL: Corky Bell told me to do that and build an isolation box over the filter.

Which I really want to do. But don't see how I can without clocking the turbo and redoing the hot side pipes to the FMIC.

 

Mod a JR CAI if you can find a cheap used one.

 

the NB's already got a big hole there...

hint: use woodworking vacuum system stuff?

 

Rob have you considered venting your hood?

 

It's on the to-do list. I once made five consecutive boosted runs from 2-7k and then promptly pulled over, popped the hood to look and got a blast of hot air that felt like I just stuck my head in a furnace. That was enough to convince me.

I'm not sure what I'm going to do though. I'm not a big fan of the extreme extraction hood (like FM and CSR on m.net). I'd like something a little more subtle. The good thing about the hole-in-the-hood, is that it does wonders for both speed and stop-n-go traffic.

I've considered these cf kidney shaped vents - tho a bit pricey for me
http://www.carbontrix.com/vents.htm
The 13x10 might work upside down too.

Also considered OE vents from other cars (there's a guy with viper hood vents in his Miata around us somewhere- tho they look like speaker grills to me).

And considered mounting one of the smaller ebay hood scoops upside down. But something tells me they'd melt soon.

 

ouch. expensive.

I've been looking at DIY type hood vent stuff. So far my favorite concept is THIS GUY.

I have a spare hood that was dontated for the cause. Smurf blue baby! But I don't have the tools to cut into it. The finest metal working tool I have is a zis-wheel. I think something along the lines of a router would be more appropriate.

 

Jig saw with a fine metal blade will cut through the hood like butter. Nice clean and controlled cut too.

 

Rx7 holes are definitely functional. I'm willing to cut some supports to make a shape that looks good. I raced with a guy that had nothing but the perimeter support in his Miata hood and it held up fine- just flimsy when open.

I cut a junk hood up using a metal cutting wheel and 4" grinder. There's nothing to the hood- bet you could intricate stuff with a dremel.