1) With the forced-induction, the compressor is going to 'get' the air, whether it receives any help from ram-air or not.
2) A look at some simple, Newtonian, F=M X A online horsepower calculators suggest that, say, for a 4,000-lb race car, with full NHRA-approved roll-cage, onboard fire suppression, driver and safety gear, we might be looking at up to an 1,820-bhp requirement in order to trip the timing light at 180-mph.
3) If so, one might look to something like a Hekimian 632-CID, big-block Chevy, with air drawn through two HOLLEY Dominator EFI units, atop a roots-type blower.
4) Accounting for the intake manifold, supercharger, dual- HOLLEYs, and maybe velocity-stacks, it makes for a 'tall' package.
5) On a 'standard-atmosphere' race day, from zero-to-180 mph, you'd never see more than 0.56- psi of ram-air boost, but it would be there for the taking.
6) The HOT ROD MAGAZINE Project Red Hat, Bonneville land speed record, 1981 Camaro used something like K&N's 100-8517-NHRA Pro Stock hood scoop, which at 244-mph, saved 150-hp worth of aero drag.
7) At 180-mph, we'd be looking at saving around 60-hp.
8) The HOLLEYs will flow up to 1,475 cfm each.
9) The 160-lbs / minute of air works out at 2,133 cfm, or 1,067 cfm / carb..
10) The Pro Stock scoop may be large enough to hide all the naughty bits inside, including velocity stacks.
It faces forwards, so you'd get the free 0.56 psi.
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I can't vouch for the online calculator. It has no provision for frontal area, drag coefficient, number of gears, tire compound, etc.. Very simplistic.
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Looks like a fun ( expensive ) project. Love the 1,200-hp turbo-4-banger!
I never saw anything like that in the 60s.