Check Out That
By Jim Salemi
Jim, I have
a Top Sportsman car that is running
in the 7.60 range, 1.09 60-ft times.
On launch, the car hits the wheelie
bars for approximately 12 inches,
then there is a gap of about
18 inches, then the bars hit
again as evidenced by the shoe
polish left on the track. The
bars extend about 12 inches rearward
of the car body, and are set
at 5.5 inches from the ground
to the centerline of the wheel.
I suspect this is unloading the
rear tires. The 4 link instant
center is 68 inches, 3 inches
off the ground. The front struts
are all the way loose (top) and
midpoint on the bottom adjustment.
The rear shocks are 6sweeps on
top (midpoint) and midpoint on
the bottom adjustment. Any suggestions
on adjustment to improve launch
and eliminate the possible unloading
John, first off your car is not transferring
weight properly. Obviously that's why you're
double tapping the wheelie bar. For starters
I would raise the instant center intersect
to 7 to 8 inches. Keep the distance from
the center line in the same area.
When you plot the four link setting, make
sure you can also have a setting that pulls
the point back because the car might transfer
weight too easily in its new location. If it
does, keep the height the same and shorten
the distance from the center line.
I would also raise the wheelie bar 1 to 1.5
inches so I was sure that it wasn't the bar
causing the unloading problem.
Hopefully this will improve consistency and
help you win more rounds.
G-Force Race Cars inc.