At 05:01 PM 6/29/00 -0700, you wrote:
>i never had either ram air hood I had on my Dak in the heavy
>rain. neither one
>gave any significant performance gains. Actually, the type of hoop filter
>you use
>gives less performance than the larger cone filters. Also - ram air hoods
>work
>only above highway speeds and the scoops must be out of the laminar air flow.
>This is the layer of air flowing over the hood as part of the normal body
>aerodynamics. Otherwise, it really does not help much. Looks great though!
Jim is correct in that a street vehicle will not see much benefit from
the ram-air effect (its so small as to be negligible). However, if
properly sealed off, they *should* give you a performance gain due to the
cooler outside air. I went about 2 to 3 tenths faster in the 1/4 mi with
my '96 and a ProGlass ram-air hood, sealed off to a 14x3" K&N with a K&N
X-stream lid.
Regarding cold air induction through a cone filter and a tube versus a
ram-air hood, unless you insulate the tube REALLY well, the hood is going
to result in lower temps at the throttle body. The reason is that the tube
is going to heat up, and its going to radiate that heat. The longer the
tube, the longer the air stays in it, and the hotter that air gets. With a
ram air hood, you can dump the air straight down into the throttle
body. Bill Tierney used to run a "ram air" system that drew air in from
under the air dam before he switched to a ram-air hood. I don't know the
exact improvement but I think it was in the .1 to .2 neighborhood (Bill can
correct me if I'm wrong.) I also recall that at one point, he had the
"tube" ram-air hooked up in addition to the hood, and he went faster when
he removed the tube system altogether and just used the hood. A big
problem with any tube type setup is that you've got to go right over the
exhaust manifolds (or worse, headers), which is probably the hottest place
in the entire engine bay...
-Jon-
.--- Jon Steiger ---- jon@dakota-truck.net or stei0302@cs.fredonia.edu ---.
| Affiliations: AOPA, DoD, EAA, NMA, NRA, SPA, USUA; Rec & UL Pilot - SEL |
| '92 Ram 150 4x4 V8, '96 Dakota V8, '96 Intruder 1400, '96 FireFly 447 |
`------------------------------ http://www.cs.fredonia.edu/~stei0302/ ----'
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