Carb Air Scoop?

[Veefan]

While I agree that pressurizing or forcing air to the carb might not be a good idea...

I think we'd all agree that using cooler air will produce more horsepower. At least thats what the dynos at K&N Engineering, say about cold air intakes. Too bad they don't make one for a VEE

If I use an NACA duct on the body, designed to not add pressure to the carb, just "offer" cooler air, with no additional drag... more HP!!! Ok, so maybe it's only 1/10 of a an HP, I'll take it!

[Larry Bradley]

Unless you have real good laminar flow in a pressure area a NACA duct won't do much good even for sniffing cooler air.
Just stick your carb top through the body work.
Larry

[Veefan]

No need for a pressure area for a NACA duct to work. "NACA ducts are useful when air needs to be drawn into an area which isn't exposed to the direct air flow the scoop has access to. Quite often you will see NACA ducts along the sides of a car. The NACA duct takes advantage of the Boundary layer, a layer of slow moving air that "clings" to the bodywork of the car, especially where the bodywork flattens, or does not accelerate or decelerate the air flow. Areas like the roof and side body panels are good examples. The longer the roof or body panels, the thicker the layer become."

[Larry Bradley]

Yeha sure, THAt what the theory is. I've tested it plus know others that tested it and it takes good air flow.
And if you see them they are always on an area of expanding frontal area, that is where they work.

The only other area to get them to work on body work like a Vee engine cover is to duct the air out on the other side to a nice low pressure area.
Like in one side through the oil cooler then duct the air out to a low pressure area on the other side of the engine cover.
So you are really sucking the air to create flow.
also of course, there is drag there getting air through the oil cooler.

Larry

[SR Racing]

[quote="Veefan]
... If I use an NACA duct on the body, designed to not add pressure to the carb, just "offer" cooler air, with no additional drag... more HP!!! Ok, so maybe it's only 1/10 of a an HP, I'll take it![/quote]

Assuming a typical day of 50% humidity, 30in of baro pressure, at 900 ft elevation and 85 degrees. A 10 deg decrease of intake temp alone is worth almost 2% of horsepower. And since fuel represents some of the total mass, lower fuel temps can also increase HP.
But only 1" of additional boost pressure will give you over 3%.

Btw,, You can also achieve "boost" without any real additional aero drag. But you have to think out of the box .. AND the measured gains can be OVER 1 REAL HP !

Sometime when you get to the shop I will show you real time on the chassis dyno.