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[x-rad]

Good question Mats, will try both see which is better, I suspect louvers up and facing rear at moment...need to buy a sheet metal air nibbler....

GregG: will gain some cooling stopped as you say, but more for looks , I still have standard intake setup...

[Greg Gordon]

I also suspect it will work better with the louvers up facing the rear. For what it's worth, my test was with a cold air box shielding the air cleaner. It's at least as good as the stock air box.

[MR2 Zig]

Just for kicks i went down the road with the hood unlatched...the faster I went the higher the hood went. topped out at 1.5 inches at 70 mph. The water temp went down a bit too.

Scott

[Mats]

If your water temp went down either your thermostat or your radiator is shot.

[zambon]

I agree with Mats on the point that venting the hood will allow more air to pass through the engine bay yielding greater drag.

BUT:
What if you combined the vented hood with some larger trays extending back from the bumper and a diffuser. You would have less air entering the engine compartment from below and lower pressure at the back of the radiator as a result. More air should then enter through the radiator. This air could then be vented through the hood. Theoretically you could have less drag than stock but with more air passing through the radiator (Or front mount intercooler if you are Greg). This could also yeild greater stability at high speeds due to less air passing under the car.

I know that this is a very complex proposal involving experimentation with an air pressure meter but someone could do it with time and not that much money. (There was a post about doing this sort of thing).

Am I making any sense here?

[Mats]

The increase in drag when opening up a hood scoop is from the increase in flow through the radiator. Normally without the hood scoop the flow is out of the engine bay down under the car, this will still be there but you add airflow through the hood as well.

The proper way of doing it would be to seal off the front completely but a small opening for the radiator, this should be vented through a sealed channel behind the front wheels or at the front of the hood (not as effective but easier). If it's colder outside you can run a smaller opening and therefore have less drag (maybe equalized by the fact that denser air creates higher drag).
A sealed undertray would also be nice of course but that's a completely different system. It could be used to increase pressure in front of the radiator of course and then you can run an even smaller opening to the radiator.

Lot of work...

[x-rad]

the hood is raising up because of the pressure under it is greater than above obviously increasing flow through the engine bay and thereby producing slightly greater cooling effect


Just dont drive in reverse!!

[x-rad]

well here it is, and I must say, it looks pretty good...still in primer

will face rear, vents on top...have not decided how to attach it, probably big rivets

you can see the engine from the rear which is cool...

[Greg Gordon]

I like that a lot.

[x-rad]

sweet! .....pics up for five minutes and a POSITIVE response!
Thanks, Greg

[John in Denver]

That not only looks good but it makes it appear that the (lets admit it) otherwise silly center section actually has a purpose.... which it now does!! I'd go for one of those.

[sh0rtlife]

i like it ALOT...what about spot welding in some small bolts so it bolts in or fullt weld some studs onto it....pop rivits are just wrong

[pancho]

I must say/agree that the plastic cover is the most silly apparently useless addition to the car.

[Mats]

Still not sure about the look, may be the primer. What's the finish color going to be?

How about pop-nuts and some nice screws?

[x-rad]

Good idea short and Mats....some 8mm ones like original or nice racing fasteners

color will match body....