a question about the bonnet vent...

[titcharoony]

has anyone heard any info on to how much (if any) the bonnet vent aids cooling? from what I can see it feeds air to the exhaust manifold? Is it purely cosmetic aka fiesta rs turbo, or does it do a significant amount. My friend claims most benefits are found after turning engine off as heat from engine bay can seep out quicker. Thoughts facts and opinions people...?

[clio_rsi_turbo]

i think its there to just help keep temps down, produced from the manifold.

[BRUN]

as far as im aware it doesnt work like a cooling 'hole'

as the air comes across it as you drive, the hot air is sucked out

very basic description but thats how i understand it works

[drsmith1979]

surely that would only work if the vent was perpendicular to the air flow? i.e. mounted sideways on the bonnet instead of head on?

it appears its simply to channel cold air into the exhaust manifold area indirectly due to its rain catcher style design.

[big hp]

as far as im aware it doesnt work like a cooling 'hole'

as the air comes across it as you drive, the hot air is sucked out

very basic description but thats how i understand it works

As brun says it draws hot air out of the engine. Hence when the engines hot you can see the heat rising.

[jwarren2k2]

it lets hot air out when it rises, but cold air doesn't go in it as such.

Next time it rains, jump on the motorway and watch the pockets of water collect on the 'bulge', none of it goes into the vent, which in turn, should show that the air isn't channelled into the vent.

Thats my opinion anyway! lol

[Clio_GTT]

as brun says it almost creates a vacuum effect at the back of the vent and draws hot air out. plus the bulge is there to cover the inlet manifold

[Purple]

It works similar to the venturi exhaust vents on the back of motorcycle helmets. The big hump on the leading edge of the bonnet creates a low pressure over the vents and hot air get sucked out the faster you drive. If you have the misfortune of driving on flooded roads, you will see a wall of water vapour exiting the vents, not recommended but pretty cool when that happens

[BRUN]

woo i was right lol