Re: Velocity Stack question?

Posted by Mike West

Date
Mon, 3 Mar 1997 21:28:18 -0800
From
Mike West <mwest@CDSNET.NET>
Subject
Re: Velocity Stack question?

Howdy.
I'm wondering, should be running velocity stacks on the 40 IDF's on
this 1835? I've been told yes and no? What are the pro's and cons?

Insight?

Give you a couple reasons I have read about, one of the sources is Berg, I
think.

First a physical law thing: with a funnel you can get more air in there
than without due to the sharp transition of the edge of the
carb mouth. That sharp edge is a pressure drop and probably cuts the
effective throat size by quite a bit. Turbulent flow versus Laminar.

The second reason is the one I attribute to Berg: he says that there
is a cloud of fuel vapor above the carb opening approximately the height of
the air cleaner (stock).

If you don't have a velocity stack or tube like contrivance that hi,
you will lose a lot of fuel. Serious mileage difference.

The various stock cleaners seem to bear this out but I really couldn't
prove it.

This is not to say a velocity stack over a decent air cleaner of the
proper height, tho if I were racing, I think I would go with the stack.

west

Original message