nilrem

i think what she was on about, is that the "vortex" created actually pushes air down behind the engine, rather than up and out...

crash_ash

surely the venturi principal states that the air travelling at speed over the bonnet and over the gap will draw air out of the engine bay. #if the air hit the windscreen and changed direction it wouldn't go into the bonnet due to the high speed air traveling above it, so surely an eddy would be caused.

nilrem

yeh, thats the way i understood it... but it has been explained that there is a large area of high pressure just before the windscreen and a low pressure under the bonnet, therefore (as i understand it) the HP overcomes the LP and "pushes" down under the bonnet and behind the engine... the front vents work because they are at a point of relatively low pressure, so do not restrict the air flow...

sas

Raising the rear edge of bonnet in almost all cases does cause a reduction in water temp, this is because you are allowing more air to exit the underbonnet area, principle been the more air you let out means more air can be let in so more can pass through the rad.
The trade off is higher drag.

Simon.

Twellsie

iTrader: (1)

my point exactly

It's Czech Mate

Would work better with gurney flaps on the trailing edge of the bonnet IMO

Looks like dogwank tho so just get a proper cooling system

zippyobrien

iTrader: (2)

all i know is that on my uncles rs turbo, t used to oover heat with out them,

now sits at a perfect temp all the time, there defoo staying, well, in the summer at least