Pressure drops, was Re: 16v carbs

[Dan Bubb <jdbubb@ix.netcom.com>]

Two ways:
1. The total flow area is larger resulting in lower pressure drop and
greater mass flow.
2. Carbs don't have the plate/cone mass airflow meter in the flow path
causing a significant pressure drop.

FWIW using a water manometer I measured the pressure drop at the
throttle body (pressure drop across the inlet to the airbox, airfilter,
mass flow sensor and misc ducting) on a Passat VR6 at 6000 RPM. 0.5 psi.
This is a pretty good intake system and it's worth noting the pressure
drop across the stock panel filter was less than a 2" H2O (0.07 psi).
So, the need for a cone filter is pretty small.
The same pressure drop measurement on my 2.0 8V CIS engine at 6000 RPM
has a drop of 0.97 psi. Not a real good high power injection system due
to the pressure drop.
2 dual barrel carbs or throttle bodies would have the closest thing to
zero pressure drop netting almost 1 psi additional pressure across the
intake valve or ~7% power increase.
There may also be some benificial pressure wave action that can help
power if the inlet tract is long enough (~18").
OTOH, everybody knows carbs will never give as accurate an A/F ratio as
FI! ;^)
Dan 

"Josh[deady]Able" wrote:
> 
> Ok..
> 
> HOW do they make more power?
> 
> Josh Able
> 87 16v Seidl
> 
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