The deal is that even thou your fuel pump is capable beyond the limits of
your motors use.. you have pretty substantial swings in pressure based on
use with a dead head regulator.... all of your fuel that is used is just
sitting there getting packed against the regulator sitting in the fuel line
in a hot engine bay.... hanging out waiting for you to use it... then when
you open up the throttle and dump fuel.... you get an instant pressure
drop... then an increase as the spring in the dead head regulator catches
up. Additionally if you set the pressure at say 7 psi on a dead head....
once you start using fuel you will find that the flowing fuel pressure is
less then your 7psi...
With a bypassing regulator... the fuel is in constant circulation at a given
pressure... and that pressure doesn't change as a result of usage... up to
the point that the pump can't keep up...
We ran a BG 400 for main fuel and a BG280 for the nitrous side and all the
bypassing regulators were Barry Grant's as well. As I recall the cost
wasn't significantly more then the cost of the dead head regulator... The
money spent of Fuel lines is another story... In the Camaro... BG sponsored
all my fuel system as Dave spec'ed it out... everything to include the
Nitrous systems.... however they didn't give me the $1000 worth of fuel
lines and fittings....
We had a rather exceptional quality fuel pressure sensor for the Data acq.
system and never saw any changes in pressure with this system... no matter
which side we were checking... that part of the Tune up never changed
unless we adjusted it.... so I know it works both in theory and in practice.
Keith
----- Original Message -----
From: "3liter" <saltfever@comcast.net>
To: <land-speed@autox.team.net>
Sent: Saturday, March 20, 2004 12:56 AM
Subject: Bypass regulator
> Dave, Keith, this is the second time this week I have heard mention of a
> bypass regulator. Can you explain the advantage? If there is enough
> pressure (or flow potential) from the source to cover any demand why is
> it necessary to bypass through the regulator. Doesn't the regulator
> lower a higher input pressure to a lower output pressure? What is wrong
> with dead-heading (or slowing flow) on the inlet side if that potential
> is always greater that what is needed on the outlet side?
>
>
>
> Also, what the name of such a bypass regulator? Or is it something as
> simple as a pressure bypass spring like on an oil pump?
>
> -Elon
|