Custom Hood vs Hood Duct

[norcalpb]

Originally Posted by gtengr

Here's an example of what I'm thinking about using the 2019 ZR1. Ignore for a second that its hood vent caused a dramatic change to the high pressure zone in the center of the windshield. Just look at the area I zoomed in on and notice how the high pressure area on the windshield ends at roughly the height of the back of the hood, and what's under that point is low pressure.

Don’t our cars come with rubber vents in the area you are circling?

[Brink]

Originally Posted by Pat

Defeats the purpose? What is the purpose?

To look like carbon fiber of course. Gotta show off that nice CF weave.

[humfrz]

Hello OP ....... you still with us ....??


humfrz

[humfrz]

Originally Posted by Pat

Defeats the purpose? What is the purpose?

Yep, I'm still waiting for that since post #2.




humfrz

[Kodename47]

Originally Posted by gtengr

The cowl piece is shielded from airflow, so I think that's debatable. I think it's likely a low pressure area exists in the airflow void where the vents would be. Also need to consider there is an underhood pressure component, and the underhood air is hotter. Seems you should know that once you cut a vent into something that the pressure zones can easily change and need to be reanalyzed.

This was proven years ago on here, probably find the threads if you have a look about.

[Lunatic]

Originally Posted by gtengr

Here's an example of what I'm thinking about using the 2019 ZR1. Ignore for a second that its hood vent caused a dramatic change to the high pressure zone in the center of the windshield. Just look at the area I zoomed in on and notice how the high pressure area on the windshield ends at roughly the height of the back of the hood, and what's under that point is low pressure.

I see what your saying.

[Pat]

Originally Posted by Brink

To look like carbon fiber of course.

Believe it or not, the original purpose of carbon fiber was not to be used as automotive jewelry. I wouldn't assume everyone thinks that is of course its purpose.

[gtengr]

Originally Posted by norcalpb

Don’t our cars come with rubber vents in the area you are circling?

I looked at it today but didn't look closely at the edges. I think I know what you're talking about but I'll have to reinspect. The cowl trim piece serves as a big inlet chamber for the HVAC, so any venting except for the very edges would get sucked into the cabin.

[gtengr]

Originally Posted by Kodename47

This was proven years ago on here, probably find the threads if you have a look about.

I searched a few variations of "windshield cowl" and couldn't find anything.

[chaoskaze]

Originally Posted by Leonardo

@Tcoat



What about cutting the side fender open into engine bay.... I know those are not that effective but it should work to a certain point too?

[Gunman]

Originally Posted by gtengr

The cowl piece is shielded from airflow, so I think that's debatable. I think it's likely a low pressure area exists in the airflow void where the vents would be.

Cowl/base of windscreen, is a high pressure area.

[Lunatic]

Originally Posted by chaoskaze

@Tcoat



What about cutting the side fender open into engine bay.... I know those are not that effective but it should work to a certain point too?

Like I did.

[gtengr]

Originally Posted by Gunman

Cowl/base of windscreen, is a high pressure area.

I saw that model and I don't think it's detailed enough to check. I've already discarded the idea due to HVAC interference, but you realize the vent would be recessed under the back of the hood about 4 inches or so towards the front? And the CFD model doesn't consider the radiator airflow, which is the target of the venting. If airflow into the engine compartment is high enough, the firewall can create a high pressure zone too. I'm guessing that is what makes the hood dance at speed.

[humfrz]

Originally Posted by chaoskaze

@Tcoat



What about cutting the side fender open into engine bay.... I know those are not that effective but it should work to a certain point too?

If I recall proper, that had been tried .....


humfrz