Fibreglass Bonnet Vent Ideas For A Circuit Car

[FiftyOne]

What ever came of the old drif6 after it hit the wall?

[Ralph Wiggum]

The way I see it Nelson if what you say was true, when you use the windscreen washers at 200kph the water would enter your engine bay and not hit the windscreen. Also if that were the case when my mates car blew the top radiator hose while at speed, the coolant would not have hit his windscreen via the gap at the rear of his bonnet and firewall. But I am no engineer.

Washers jets and coolant would bothe be released at much higher pressure than the 0.1238psi Nelsonian measured. Hence why they both made it to the screen.

[AdamIan69]

Buy a bigger radiator and intercooler, ceramic coat and fibre glass wrap your exhaust and turbine housing, shroud your radiator to intercooler and intercooler to bumper, ceramic coat your intake manifold and cold side turbo piping that sits inside the engine bay, separate your auto trans oil and coolant, run less coolant and more water on track days, raise cooling system pressure to 18-20 psi and don't sit in other cars slip streams if /when possible as air is not as dense in the slip stream.

You could try all of that and see we're it gets you?

Ralph, coolant would be released at somewhere around 13-15psi. But once released the coolant won't travel to the windscreen under pressure. It will travel there because the coolant is carried there in the flow of air. I have also been told of a bloke that ran a raised rear bonnet and got oil on his windscreen when a rod escaped the block.

Edited 02/01/14 03:00 PM by AdamIan69

[sexual harrassment panda]

I have already removed the rear rubber seal and have done many circuit days with and without it.

From my understanding, the pressure difference between the bottom of the windscreen and engine bay forces air INTO the engine at speed. Not out. This would be hot air at the circuit on a 30deg day. I.e. a venturi effect that you don't want at 200kmh.

This is why older cars had rear facing scoops though for a different reason. To get air into the engine intake, not out.

Opposite would be true while stationary in a road car I guess.

Looking at the vent position of Fords top circuit cars like the GT40 and RS Focus have vents toward the front just behind the radiator.

This is the plan but may also put some at the rear of the bonnet bulge too.

your pic shows the high pressure and low pressure areas

front of bonnet = high pressure = air in

rear of bonnet = low pressure = air out