I THOUGHT about putting a flap under the front cross member to create some
low pressure in the engine compartment, but have not.
I DID borrow a trick from the West Coast guys and am directing air through a
series of 3" holes in the firewall with the air being directed up through a
modified cowl vent.
BTW, various vintage groups frown on soft or hard tonneau covers (or both)
for reasons of driver safety.
Finally, now that I know how little HP I have at the wheels I am going to
have to get more creative.
Joe (A)
> Yes, taping off the grill opening reduces the drag, because, you've
> eliminated
> the drag of the air going over the engine and through that forest of draggy
> parts and poor on non-existent exit design for air.
>
> On the Salt flats this was about a 2 mph difference in just reducing the
> opening to the front of the car.
>
> Most serious race cars have ducting that takes the airflow from the radiator
> and routes it outside or into a low pressure area. The F-1 car are a good
> example of how important this radiator flow exit is. They even have the exits
> as a winged shape that probably gives a little overall downforce and also
> directs the air to the wing. Ferrari is a good example of this.Doing this
> same
> thing on a TR will do the same thing, but don't look for some catastrophic
> differences. Maybe at the end of the shute you will be able to pick up
> another
> car or two though. I also taped off the openings between the fenders and the
> hood with helicopter tape and this also proved beneficial. On the TR coupe
> cutting off the lip of the hard top on the windscreen helped. Air is lazy and
> will take the easy way every time.
>
> Ducting air in flexible wire tubing 3" in diameter at 100 miles per hour the
> opening is reduced to about 1.5". Smooth tubing retains most of its diameter
> as the boundary layer flow increases with the speed. Given that as true, then
> it makes sense to make your brake ducting of formed fiber glass over a mold
> so
> the interior is smooth and this allows you to REDUCE the overall diameter (
> frontal area) and still have the full benefit. Fun stuff to do and it really
> does all count.
>
> Given a good vacant road you can do coast downs without power that will help
> to see how the aero dynamics effect the car. When doing these coast down, the
> thing is to be very careful to not accidentally cheat.
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