D.I. COLUMNIST
Tuned Up
with Will Hanna
S
o much of
what we do in
the faster rac-
ing classes re-
volves around a timing
curve anymore. Even
the Super-class racers
are playing with tim-
ing to minimize rpm
climb on the throttle
stop. I think a driv-
ing force in the “curve
game” was the advent of
torque converters in the
heads-up classes. Obvi-
ously the fuel cars have
been doing it for a while
as well, but the torque
converters in the higher
horsepower cars really
made pulling a chunk of
timing out a necessity. It
didn’t take long for the
clutch cars to catch on
they could benefit from
them as well.
Before we started us-
ing big timing curves,
we had to pull taller
gears and/or run less
clutch. On blown cars
we could run the mo-
tor rich in certain parts
of the run to calm it
down. I’m not going to
say I know what exact
changes turbo or nitrous
cars were making be-
fore timing control re-
ally took hold, but the
bottom line is those adjustments
were much more of a “coarse” knob
adjustment than “fine” adjustment.
Also, fuel, boost and nitrous changes
are not as quick as timing. Using
timing controls allows us to spot-fix
the starting line and “shake zone”
parts of the run rather than make
changes to the car’s set-up that af-
fects it the entire run.
Now the timing curve is the pre-
dominant tool tuners use to control
wheelspeed. As a consultant who
has worked with many teams strug-
gling to get down the track, the three
biggest mistakes I see is not pulling
enough timing, not having the curve
in sync with the wheelspeed graph
and trying to make corrections too
close to the problem area of a run.
Let’s start with being in sync. I
have seen many people who will zero
their data logger graph off the first
movement of the driveshaft. Some
data loggers do this automatically.
However, this is not when your tim-
ing curve and other timers start.
The timing curve and other tim-
ers are going to start off either the
transbrake, clutch switch or wide-
open-throttle switch. It’s important
to zero your graph off what starts
your timers. If you are getting into
tireshake at 1.1 seconds on the graph,
but the graph is zeroed off the drive-
shaft, then when you go to correct
that spot on the graph with timing,
1.1 on the driveshaft is not going to
equal 1.1 on the timing curve.
If you are using a MSD Power
Grid and Racepak vNet, this is
pretty easy to do since those sys-
tems will talk to each other. Make
sure you are recording the “launch”
input into the Grid and zoom into
the approximate launch point. Move
the cursor over to when the launch
input goes from 1 to 0. When the
cursor gets to the point the value
goes to zero (this will be midway
down the ramp), zero the run right
there.
If you don’t have a data logger
that syncs with the ignition box, I
highly recommend adding an event
channel to your data logger to have
a definitive input when your tim-
ing curve starts. If that is not an
option, if you have a known event
you can clearly see on the graph,
like a leanout opening
up, you can back up off
that event and zero the
run. With a Grid, I have
also gone back into the
ReView file and made
note of the launch zero
point, then went back
and found that rpm/
point on the data logger
graph. When the tim-
ing curve is in sync with
the data logger and the
driveshaft curve, if you
see it start to shake the
tires at 1.1, you can make
timing adjustments
based around that event.
That leads me to the
mistake of trying to cut
a problem area too close.
If it starts the shake at
1.1, you don’t want to
pull timing at 1.1. You
want to be at least .2
to .3 ahead of it. It still
takes time for the pro-
grammed change in
timing to take place and
you have to get it calmed
down before it gets in
trouble. The same goes
for ramping the timing
back in. The risk/return
often times is in favor to
ramping the power in a
little later than when
you think you can get
it back in. Usually you
pick up a lot less than
you think by agonizing over starting
the ramp back in at 1.4 or 1.45. You
sure lose a whole lot when you put
it in too soon, though.
When I was learning the timing
game, I asked for some advice from
another tuner who had been doing
it early on. When asking how much,
he said, “It’s just a number.” Differ-
ent applications will require differ-
ent amounts of timing, but if you are
trying to fix tire shake with timing,
one or two degrees usually won’t
cut it. Also remember the worse
the track is, the less prone it will be
to weak shake. Feel free to “park” it
in those conditions.
Also, remember to be tuning for
the next run, not the one that just
happened.
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