I feel it is time that I chime in on this one. I am the one who
invented this particular item that was used in 4 cars that I am aware of
at nationals last year. Everyone thinks that the tank in question was used
to allow you to run minimal fuel loads. IT WAS NOT INTENDED TO DO THAT.
The reason why we put the tank in the car was because when the car sat for
to long the fuel pump would not pick up fuel. Everyone who has any experiance
with converting cars to fuel injection knows that the high pressure pumps have
very poor pick up capabilities. They do not pick up fuel for squat. So what
we
did was put a small tank in line that had an exit on the bottom . It also has
a
fitting in it to pick up fuel that is circulated back from the fuel rail, and
a final
fitting that goes out the top of the tank and returnes fuel to the tank
through one
of the two vent lines on the top of the gas tank. The first in fitting was
fed by
a primary low pressure fuel pump. Those type of pumps have excellent pick
up capabilities and work well with non fuel injection type gas tanks. The
fitting on the bottom of the tank gravity feeds to the high pressure fuel pump
that has no problems with pick up when it is gravity fed. Next the fuel
exits the fuel pump goes in the fuel rail, past all the injectors, and out to
a fuel
pressure regulator. The regulator is the first restriction in the line. It
keeps
the fuel pressure very steady. The fuel flows out of the regulator and back
to
the tank in question. This helps to keep the fuel vapors down. If the fuel
came
back into the gas tank directly from the fuel pressure regulator it would
really
cause fuel vapor problems in the tank.
When the secondary tank is full any excess that is not used by the motor
flows
back into the gas tank at 2 to 3 psi. not 40.
Secondly I would like to dispell a myth about the tank in question. Everyone
thinks
that it helps to save weight by allowing lower fuel loads. Well it does, but
the down
side is that when you run very little fuel the fuel heats up quickly. When
the
fuel heats up it changes the way the car runs dramatically. On the
dyno the car looses 20 hp when the fuel warms up to 180 degrees from
90 degrees. On the dyno we noticed that when the fuel heated up the
car would run richer and richer. We figured this was becuse the fuel atomized
better hot than cold and so the car needed less fuel when it was hot. The
problem
is the fuel starts out cold and warms as the car runs. If you run3-4 gallons
in
the car the fuel does not warm up much. Run one gallon and you are in trouble.
The car will get slower and slower from run to run. So it is much better to
run
more fuel than less from a power stand point.
They also say that if it is allowed it will add more cost to setting up a SP
car.
Give me a break!!! It cost 3,000 minimum from start to finish to set up fuel
injection on on an SP car. That tank cost 40 bucks from any speed parts
catalog. If you spend 3 grand on fuel injection for your old car it should at
least work right. It was a real pain in the ass to prime the fuel pump every
time
we put the car on the trailer to bring it to an event.
If there is an issue of whether or not the car can complete it runs on the
supply from the tank than make the tank capacity smaller. You only need a tank
that has a volume of 1 pint to do the job the way I intended it to be used.
If the tank is made illegal most old cars will not be abel to
compete with new expensive cars that came with fuel injection and have fuel
tanks that work well with fuel injection. So is it really a cost issue or is
the SEB
trying to make the old cars which cost alot less to build uncompetative?
Flame Away
Chris
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