Air flow through hood scoop

[ItBites]

Actually 6-7 Hp would not surprise me. This would be 1.5%, which is not bad for a $50 mod, consider head porting for $1500 (or more) and a result of 10% improvement, the ROI (return on investment is good).

As I have stated above twice, the compromise made with a little filter may be beneficial for other reasons (space limitations etc), but the HP loss is real. Racers in any class where limits on motor build are in place would kill for 6 - 7 HP

Thanks for some data. I was guessing at 1%, but 1.5% with dyno data is great.


On the cold air subject. Cold air is great PERIOD... I think I recall some folks did a good scientific study looking at temps entering the cylinder (not 1:1 comparison with temps entering the carb) and they found 1% for every 10 degF of drop in temp of the intake charge at the valve. Good reason to seal to the hood, but of course everyone knows that old trick?

Ram air is not a big winner. I recall other data that gained 1% at 100mph due to ram air. I think they had a good inlet too. Our less than optimum inlets would likely show less gain, but some is there to be had at higher speeds. remember dynamic pressure rise is =1/2 * rho * v^2 - (increases with the square of the velocity), so 50mph would result in 1/4 the ram effect gained at 100mph and so on. At 200 mph you might gain 4%!!! Try it and let me know...