QUOTE(SirAndy @ Jul 17 2014, 12:28 PM)
QUOTE(edwin @ Jul 17 2014, 01:27 AM)
What would running a deeper section of stiff rubber across the full width and back along the sides a little do for cooling?
That might not be as efficient. They are placed to specifically aid the air flow where the air comes down from the cylinders.
When you look at the underside with the car on the lift, you can see that Porsche was aiming for those two spots in particular to help with moving the hot air away from under the cylinders.
A lip over the full width might actually hinder cooling ...
PS: Are you running a rear valance? That will trap hot air. Also, unless you go over 100mph on a regular basis, no front air damn will help with cooling as well.
Andy... I think you are wrong about this..... but I could be wrong too.
If you put a strip across the whole width of the engine compartment, you create a low pressure area behind it. That will help pull air through the engine and out the back. That's why it works to remove the rear valence, it allows more of the low pressure area behind the car to pull air from under it.
If you really want to increase cooling and downforce, reverse the airflow over the engine. Pull air from the bottom, and exhaust it out the top. The Chaparrell sucker cars did this in 1970 Can am series.
"Officially known as the 2J, the 1970 Chaparral has gone into history as the 'sucker car'. Setting aside his long experience with wings and aerofoil, Hall found a completely new way of generating downforce and without the penalty of additional drag. Using a Rockwell snowmobile engine, all the air was sucked from underneath the car creating a low pressure area; the 2J was literally sucked to the ground. The two cylinder engine was installed on top of the gearbox and the air was blown out the back by two large fans. The area was sealed off by lexan skirts that were connected to the suspension to keep them attached to the ground at all time."
One of the problems a 914 has at high speed is the body starts to lift in the front. Adding a air dam at the front improves it tremendously. It also improves the airflow through the GT oil cooler because the exit is in the low pressure area behind the air dam.
I have considered trying this for a long time. I am going to make a strip from rubber and run it the width of my car. I will let everyone know if it works or not.