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Dusterbd13-michael
Dusterbd13-michael MegaDork
10/6/19 3:25 p.m.

R theory makes a set that follows the underhood bracing on my nb. Really looks good from the pictures i have seen.

However, i cant seem to find any write ups of install or detailed pictures/close ups. 

Eith my engine swap car, ill only be able to use the four outside vents, not the center. In addition, i want to make a pair to fill in the bracing at the back end of the hood, which is a higher pressure area. These will be to feed the air filters. Fronts will be to aid in underhood pressure release, and hopefully add some more cooling system headroom.

Anyway, can you guys post some pictures of the details of install, final close up appearance, and maybe even how they are cut and shipped? 

I have tried google, but my Google-fu is weak.

The alternate idea is to cut these areas out completely, and use screen door mesh and a nice bezel. Or expanded metal. I doubt it would lookas neat as the r theory stuff, but would be far cheaper and easier. Im just not sure what the difference between them in regards to lift and cooling efficiency would be. 

Anyway, thats my current brain game. Feel free to discuss/link/etc.

Robbie
Robbie UltimaDork
10/6/19 7:42 p.m.

Just remember, front of the hood is low pressure, rear of the hood is high pressure. Only a rule in the center of the car, as you approach the sides anything can happen.

Also, if you're looking for high pressure air for an intake, no pressure is as high as the front of the front bumper. Base of windshield is ok, front license plate is better.

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
10/7/19 3:10 a.m.

the other thing to think about is if your exiting hot air out of the front of the hood, that means you'll be ingesting that warm air back in at the back of the hood.  It's almost as bad, but not quite, as just using the air under the hood.

so the front of the bumper has 2 benefits:  1) higher pressure than the base of the windshield.  2) cooler temperature than the base of the windshield if exhausting air from the engine bay.

"front gurney" flaps, and Vortex Generators can help you put a low pressure zone over the middle of the hood.

also...

Dusterbd13-michael
Dusterbd13-michael MegaDork
10/7/19 5:57 a.m.

The 4 forward ones are in a low pressure area. The two rearmost are in high. Those are primarily cosmetic for me. They won't be big enough to do real work, such as feeding the air filter. In all honesty, ill probably block them off. 

Main reason for this is to create a venturi effect to pull more air through the heat exchangers. However, i cannot use a waterfall in the middle as i would like, due to the engine swap. And, i think they're ugly on a miata.

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
10/7/19 2:51 p.m.
Dusterbd13-michael said:

Main reason for this is to create a venturi effect to pull more air through the heat exchangers. However, i cannot use a waterfall in the middle as i would like, due to the engine swap. And, i think they're ugly on a miata.

Nope, you can't do the central waterfall in the middle because of the "V" and the air intake in the middle.  Neither can the V-8 M6 GT3 car I linked.  However, that 'aft' end of the waterfall will be over the headers where you should have some vertical space, and the V6 being shorter than the I4 might help too?

I'd hazard to guess that you've got enough room to get a bend from the 'back corner' of the rood's "X" brace down in front of the engine to about the middle of the fans?  Then it's just a vertical wall either side (sharp corners are your friend for the sides, generally).  Following the side triangle out to the corner has the benefit of putting the exit into the lower-high pressure area at the side-windsheild base.

AFAIK, this will help the heat-exchangers be more efficient, and should give some front downforce too (which I think is why you see a similar hood setup for both the BMW and Mercedes GT3 endurance cars)?

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