In any form of heads-up “index” competition,
the theory is the same: If you could cut
a spot-on “four-oh” light, and everything
on the car was working perfectly on the dial, you
would win every time! Out on the track, of
course, events usually play out a little differently
then while driving the barstool or the Lazy Boy.
Variables, especially those of the fuel-curve
variety, are the archenemy of ET consistency. With
engine displacement in the super categories getting
into the supersize ranges, ever-increasing demands
are placed on fuel delivery of the traditional,
single-carburetor setup. Getting the carburetor
to deliver the correct amount of fuel and air throughout
the entire range of engine RPM based on engine
demand is the key to winning; it can mean the difference
between going rounds or pushing back onto the trailer
and going home early.
WOT Did You Say?
Determining what the carburetor is supposed to
do at wide-open throttle (WOT) when the engine
is at full boogie is one thing, but getting fuel
delivery to behave on the way to WOT is another.
A carburetor that bogs out or stumbles on its way
to the top is never going to get there quickly
and consistently enough to light up the win light.
The real trick is delivering the right amount of
fuel at precisely the right time to get the engine
going as quickly and consistently as possible.
At WOT, things add up to a fairly predictable
equation. However, as converter stall, torque loads,
throttle stops, pneumatic shifters, and track and
air conditions get factored into that same equation
at intermediate fuel delivery, it becomes much
more complex. In the case of a throttle-stop racecar,
nothing about the setup as a whole is designed
to be run at the unnatural, low- rpm condition
that the throttle stop creates after the initial
hit. Unless the carburetor is specially prepared
for this unnatural spot on the curve, a lean or
rich condition can occur, and the engine will stumble.
Worse, if the shift timers are kicking in at the
same time the engine is stumbling, the dialed elapsed
time will almost certainly go astray. Thus did
E-Carb Competition Carburetion (Everett, Wash.)
create its T/S-1050 calibrations specifically for