The question though, at speed, would there be some sort of turbulence (maybe not the right word) behind the hood, which would trap any escaping air and force it back into the engine towards the radiator?

Did you even read the thread?
At all?
Even half-way?

Why do that? Hell you might learn something.

so i see your suddenly backing away from the air cooled engine theory... good idea

did you read this p0st? https://www.rx8club.com/showpost.php...7&postcount=76

I can see your [sic] suddenly backing away from the substantive comprehension of the English language.
If you somehow actually construed that I was advising that the Renesis is air-cooled, then you have completely gone off the deep end.

You are this forum's Bill O'Reilley, you know that?

You are now officially on my ignore list. Enjoy!

lol^
Dam it! I was just at Homedepot today. Now I have to go back today ;) and buy some of this stuff that Expo1 used :)

.............You are this forum's Bill O'Reilley, you know that?..........

FWIW, I would consider this to be a compliment.


Removed the rubber strip and am using a small piece of hose to prop up the center of the hood. Cant really tell if it helps. The hood gets extremely hot (no plastic covers). This car really needs some water/oil temp gauges. This is my next mod.

Oh, and during a rain shower I noticed the water drops being gently pulled in at the center of the hood. But this may be dependent on how much of a gap I have, how fast I was going, etc. Even if air was getting sucked in I would still maintain the hood gap for stop and go driving situations.

Something else I do is open the hood when I get home. Having a garage helps. I figure over the years this will help hose longevity among other things. Probably not necessary but it cant hurt.

Impossible, everyone knows the mod works because "We are simply giving the air that goes through the radiator more choices for an exit."

Sounds to me like you got the faulty result the rest of us who actually took time to find out what was going on found - no air escapes, rather slight amounts get pulled in... which hoses the above comment :cwm27:

That is particularly sad. You do know B.O'R's history, right?

Pulled into the gap? In a ride to Tucson through the Rain on Saturday (first rain I've driven in in almost a year), the rain sprayed quite distinctively at the windshield once it left the lip of the rotor crescent.

Just done this mod & this morning the water on the hood did go round & back under. This was at 60mph, it doesn't mean rain will though as it's in the air flow & not under tension to the hood.

its a conspiracy :uhh:

Which front bumper do you have?

MazdaManiac: Most of the detractors of Bill O'Reilley are from the far left who attempt to silence or vilify anyone they do not agree with. I am not of the far left. And even though Bill can come across as arrogant I find his common sense approach very refreshing. So we may not agree on political issues, I do agree with you on the hood mod

Let me state it this way

Do I have the hood mod
yes

Does it work
Based on testimonials given in this thread I would say so

Does air move in or out of the hood
My understanding is that there is a high pressure area at the base of the windshield (center only, not the sides?), so air should move in. But this may depend on how fast one is going, size of the gap, etc. I dont really know.

I have no plans to undo this mod. My only concern is the high hood temps under certain stop and go situations. I am thinking about reinstalling the engine cover. I guess this would help. Not really sure. Maybe I am concerned about a problem that doesnt exist.

And what the pressure is under the hood as well. :banghead:

Heat = High
Cool = Low

I have moderate experience as a pilot how this stuff works. Aerodynamics and Weather play a part here. High pressure will always move to low pressure. That is why thunderstorms are storms.

You heat up a sealed bottle of water, what happens? It goes to the lower pressure, outside the bottle.

Leading edge of a wing: realitive wind hits leading edge of wing and is directed up, creating a high pressure over the wing. The top surface of the wing is low pressure. The wing want to go to high pressure, above the wing. That is called LIFT.

Only makes sense if the engine bay is hot, it want to get get out to the lower pressure. If you speed up, venting will increase if venturi is formed over the hood. Same way fuel is drawn into a carb, with air movement.

I removed the back seal on my hood a long time ago, seems to work some. Need more vents though. Don't want to drop a bunch of money into a vented hood.

I use a fog machine for DJ gigs. I am going to use that and some fans to see where the highest pressure occurs on the hood. That would be the best place to exit the heat under speed. Standing still, there maybe a better place to vent.

My question is, what engine bay area(S) have to stay dry?

almost none. plugs, wires, coils. wires and connectors are generally shielded and protected and don't need much thought put towards them. That said you don't want them to be immersed in water, so don't drive into a lake.

you do not vent INTO a high pressure zone, depending on the relative pressures of the zones you are connecting you could stall or even reverse airflow within the duct.

I think you may be better off to make a LONG hollow stick/pointer and blow the fog/smoke out that while you're on a long empty stretch of freeway.

I wouldn't think fans would give enough airflow at speed, nor would they give you nice smooth airflow without the long straightening section.

Oem

(edit) with engine cover still in place

I will try that.

awesome, be sure to post pics/video up if you do - I've been wanting to do this on the gf's RX8 and my Supra. (be interesting to see over bonnet stream, and where smoke near the engine bay intake went)

Any idea on what the best (and safe) thing to create a good 'solid' smoke would be? I wouldn't have thought the dj/disco fog machines create enough (or thick enough) fog to see clearly.

I did this hood mod. It works great! I recomend it to anyone who has a 8 thats in the hot spots of the US.

Since I'd likely be painting my hood silver (I don't really dig the mixed body panel look), I thought this might be a nice alternative. I haven't heard anyone talking about fiberglass hoods though. Any pitfalls with them?

http://www.aerokits.net/cart/index.p...oducts_id=2443

Those are the guys that gave me my GT-Factory vertical door kit after SEMA two years ago.
I visited their shop in Baltimore - they seem like a good bunch of people.
The hood you are looking at is made by GTP, who has mixed reviews.
Certainly cheap enough. I might have to get one of those.