To reduce heat, you need a vent at the leading edge of your hood past the radiator. See Mitsubishi Evolutions as an example of this. Not to be critical, but your air intake is in one of the worst spots of the car, up high and next to the radiator, I know you don't have much to work with but, a cowl would work if you were to move the inlet to the firewall, I've seen this setup before on cowl hooded Mustangs with centrifugal blowers. If your trying to lower your intake charge by lowering your under hood temps, I think you have an uphill battle you'll never win without an intercooler or methanol injection.
