Re: Tuning Air flow

[PDQSHIP@aol.com]

Not sure I enjoy giving up my secrets either tho I tend to do so.....  An air
inlet in the early sciroccos differs from the air horn from an audi, but
that's cuz vw chose to look at it, but it's not critical on a 100hp app, so
why bother....  I assure you that if you work on the audis, you can see the
different apps audi uses for air intake, and there is a reason.....  Now, if
you change a perameter in the intake, such as "tuning" the intake manifold or
generally increasing the stock demand for air, the air box will benefit from
some modifications....  Let's say for example that, my 5ktq takes in 350cfm
(example guys, no secrets out) thru the air horn at lets say 5500rpm WOT,
generates 162 hp stock......  Now, I've made car modifications to the tune of
350hp @ 5500 WOT, my demand for air will far exceed that 350cfm (example lets
say double @ 700cfm)  thru the same intake tract.....   Again using the
exhaust argument (and by the way the exhaust 95% efficiency at the manifold
is about 94% off when you apply a turbo app), you have a hi hp engine which
now needs larger exhaust to maintain the same backpressure......  Now go back
to the intake side, if the demand for air is now much higher than the stock
162hp flow (remember over double the hp with no intake man mods) wouldn't the
"tuning" of all the air leading up to that intake be a good idea?  Me thinks
so, using the same theory as the exhaust, you have a restriction of flow
(which by definition is and can be tuned), and that restriction is not
calculated just to the air box, it's calculated to outside air..... Again
using the same theory as the exhaust, you can get the same restriction by
increasing the diameter of the intake tract, and I argue that the most
obvious "restriction" is not the fuel dist to the intake (add thru turbo and
intercooler on a turbo), it's right there, in that air box and that horn.....
  Look at a set of mikuni stacks, they can be tuned, and the application is
NO different using an airbox....  Audi just doesn't pick hoses of a certain
diam or horns of a certain length and diam and change the app cuz they want
to make more parts, all air to the t-body is tuned, by definition and
application....   Look to the racers books, this theory is there, and a very
close look at the turbo applications for audi, shows this to be true, maybe
to a lessor extent to the nonturbo cars, but me thinks a 20v non turbo will
benefit the most next to a turbo car on this thought.....   Maybe a
clarification of your definition of "tuned" might help, I'm thinkin your a
little off on the exhaust argument, but given you're right on it, your logic
follows on the intake side.......  I take a more simple definition of
"tuned", tuned is reaching the optimal parameters based on the demands of the
engine, whether exhaust manifold or pipe intake manifold or tract, each
variable of diam vs length (resonance and direction, sure), can be tuned, and
should be tuned to the demands of the engine and/or driver...

Scott