Cold air inductors,
Great big gulps of cool air is best! The jiffy pop system is a definite
step in the right direction! Dont let those "goofy" comments affect your
development. Form follows function.
At 5500 rpm the 360 v8 should require about 580 CFM of air. At 70F the
density and sea level assume a density of 1. As the air heats up, density
drops. At 125F density (very approx) is around .7 of what it was at 70 F.
Your CFM requirements go up to 750 CFM @ 5500rpm. Add pressure drops due to
routing and air cleaners etc. and the number keeps rising. OUch... Dont
think the little throttle body can cope without those mods ive been hearing
about. Additionally, your power output drops 1% for every 300ft of
elevation over sea level ( approx rule of thumb). Your computor can only
compensate so much. Bottom line, the more cold air you give your motor, the
less you punish your ET. Sizing the ducts for the ram/cold air system
requires a lot of fluid dynamics/duct flow calcs and would be specific to
the implementation of the system. Open air systems (FABM etc.) may flow
(and probably do) the CFM, but the throttle body without mods may not. With
cold air, you dont need to do as many mods to get the same output. Add
altitude and it becomes clear that cold air is key! Pretty obvious rules
of thumb say short routing, smooth large diameter tubes and large plenum for
the air box will all help. Seems like the ram air hoods are the best bet
from a routing standpoint, but they have too small of an opening (like the
Challenger "sport" hoods, great looking, but not very functional). The
jiffy pop cold air system (JPCAS?) may need a larger dia "popper" or
possibly two inlets, one on either side to really flow at the limit.
my .02
BKB
At 01:57 PM 6/22/98 -0500, you wrote:
>At 05:57 PM 6/21/98 , you wrote:
>
>>I am very suprised at these numbers. Especially at high speeds. I
>>think we're going to have to scrap the open element air cleaners.
>>Raising the air temp by 40 degrees *can't* be helping our
>>performance.
>
>I wouldn't be so quick to scrap the open element air cleaner just yet. The
>question still remains, is it better to take little sips of cool air or
>great big gulps of hotter air?
>
>--
>Mike Crumley mcrumley@airmail.net
>97 Dakota Regular Cab Short Bed
>3.9L V6 3.55 Auto Rhino Liner
>Bug Shield Mud Flaps DDBC
>
>
>
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