Craig & Theo,
Air cleaners do make a difference. Try a test I did 25 years ago. Find =
a level, deserted road and determine the time for the car to accelerate =
from 2,000 to 5,000 RPM in second gear. Start at about 1,500 RPM and =
put your foot down smoothly but rapidly. The idea is to avoid surges in =
the engine, gear train or interactions. Run a few trials to get an =
average. Now remove the air cleaner top and element and repeat. My =
times went from 5.5 to 5.0 seconds with the car in that state of tune, =
gears, etc. I was instantly convinced of the need to lower air intake =
pressure loss. Suspect the current system was only the best and most =
convenient available to Rootes at the time and wasn't engineered to =
mimimize horsepower loss.
Craig mentions 100 HP loss from engine to chassis dyno. Don't know the =
chassis dyno set up, but if the hood was closed, don't neglect the inlet =
air temperature. If the carb ingests air through the radiator at, say =
the 180 degree temperature of your thermostat, versus 80 degree air from =
outside, the difference is about a 20% horsepower loss! For Craig's 440 =
HP monster that would be about 44 of those 100 HP lost. The air density =
is the difference. It's equivalent to about 2 jets sizes richer on your =
Holley 4-barrel. Second conclusion, cold air is good! Nothing new =
here.
Bud
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