Gosh, the last time I saw JPS on car was way back.. a Lotus Esprit.

I styled my car in the old John Player Special F-1 livery.

Very good. It reminds of the ole Hertz Mustangs. Similar stripes.

I haven't seen CFD, or tunnel testing, that did not show the cowl area as a high pressure zone. The turning of the air from a general horizontal, to more vertical direction, causes high pressure.

Granted, there are probably cases where something else is influencing it, and making it low pressure, but i have not seen it.

This is true.

That area of the car is always higher pressure. I am sure there is a way to make it low pressure, but in general, that area is a terrible choice for evacuating air.

Right, but it's nearly always modeled as the hood running into the windshield as if it's a simple obtuse-angled corner, ignoring the void area that is recessed towards the front of the car and under the rear of the hood. And the influence of an engine bay that has trapped a lot of air that wants to escape is also generally ignored. The Corvette example I pointed to earlier, while it is a different car, demonstrates that the high pressure area doesn't necessarily have to travel below the hood line and towards the front of the car. I'm not trying to say that I'm right, because I do understand your point. I just haven't seen enough to convince me it is 100% factual in this case.

Going back to your case, I have attached the same picture with some arrows to point out areas.

https://i.imgur.com/VXhiMZI.jpg

Red Arrow: Best for evacuation, lowest pressure
Orange Arrow: Good for evacuation, low pressure
Yellow Arrow: Worst place for evacuation on the entire hood. This location has the highest pressure and would result in the least productive evacuation. Likely air would actually make its way *into* the engine bay.

People reduce complexity on CFD models to aid in solving. There are industry standards (followed by OE's, privateers, and race teams) that are accepted because they do not result in incorrect results.

Hope that helps,
Eric

I agree, but my aim wasn't to investigate this as the best option. I was looking at is as a possible way to get "some" venting without cutting the stock hood or dealing with aftermarket hoods. Also, the theoretical vent location is not on the surface of the hood, it would be on flat vertical face under the rear of the hood, and recessed about 4" toward the front of the car as measured from the vertical plane at the back edge of the hood.

I don't mind if I'm wrong. I just don't think pointing to the pressure distribution on the top surface of the hood tells the full story, or that the underhood pressure isn't a factor.

To see the carbon weave. It doesn't sound like OP is making a literal race car, so the carbon is purely cosmetic. That's why I get carbon parts for my car

May I put forward the Beatrush Underpanel. No cutting, modding or replcing of the bonnet required. Proven to work, might even add downforce if claims are correct. Pulls heat directly past and away from the manifold too. Only downside is that it's not cheap, but still cheaper than a modded or aftermarket bonnet.

I also thought that might be a good addition.

For what it's worth, carbon parts can add functionality to street cars, too. To say it is "purely cosmetic" I think is selling carbon short. Maybe that's all he cares about, but true carbon parts bring more to the table than style, regardless of implementation or appreciation.

Under hood pressure should be counted for the venting. Pressure difference really makes air move.

I did an experiment for the vent at the cowl area on 2016. With the help of a Gurney flap, at least it blows out some air. I guess a blocking vertical barrier that divides low pressure zone and high pressure zone could help more.

https://youtu.be/I-uIh1YaeZY

https://youtu.be/yCusyzwHdOY

I know it cannot blow out as much air that hood vent can. But could be better than nothing.

Or do make your own like this, @gtengr .