Thanks for your formula it is a bit more scientific than mine. I guess
I'm just a "seat of the pants" type guy. Tom Burkland did say that the
scoop should bring you to sea level efficiency if it is working
properly. He claims 8 lbs. of pressure measured in the scoop on their
former Comp Coupe at 300 MPH. Others have said the static pressure is 1
1/2 to 2 lbs at 250 MPH.
Tom
"Lawrence E. & Cathy R. Mayfield" wrote:
>
> Hey Tom, good job on the formula! I had went about it a little differently
> though but with the same, I hope, results!
>
> I developed the following:
>
> Inlet Area (in sq) = (Disp * RPM *VE) / (MPH * 2112)
>
> Where: Disp is engine displacement
> RPM is RPM at which you want to run
> VE is volumetric efficiency of engine (1 if you don't know)
> MPH is the at which you want to run in MPH
> 2112 is a combination of conversion factors)
>
> So, an example... my car, 306 CID, 200 MPH, 6250 RPM, .8 VE
>
> Inlet area = (306 * 6250 * 0.8) / (200 * 2112) = 3.622 in sq.
>
> This provides for an exact balance of the engine needs. I would use a
> volumetric efficiency of 110% to account for some ram air effects, however.
> This is an interesting equation because the slower you go the larger the
> scoop. I think this means that when testing on the dyno that you need a
> large plenum and inlet. Tom, does your equation do this also?
> Unfortunately, adding a scoop or the inlet adds some drag to the car, but
> if confined within the frontal area envelope, shouldn't add much, if any.
>
> Neat stuff, this!
>
> mayf
>
>
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