|
Hoosier
is now providing “Dynamic Spring Rate” data for its ARCA speedway radials.
This should be used as a tool to help racers minimize chassis variables caused
by normal tire variation. Each
rating represents the average value for that individual tire. The difference in
rate can be used to match up tire sets to either maintain or change a cars’
handling characteristics. The
actual in-service tire spring rate will often differ as it is dependant upon
the actual tire operating pressure, which in several cases is not the same as
the spring rate test condition. However, the relative rate difference between
two tires will remain the same.
The
basic rule is: 1-psi change is equal to a 40-lb change in spring rate.
Example: (For sake of simplicity assume other 3 tires have the same
rates both sets)
Set
#1 RR tire has a Rate of 2350 lb/in
Set
#2 RR tire has a Rate of 2390 lb/in
If
you want to make the spring rates of these two tires the same, you could make
one of these adjustments:
-
Raise
the pressure in set #1 RR tire 1 psi (cold) to get a 40 lb increase in spring
rate, or:
-
Make a
+ 25 lb/in spring change on the RR, along with a + .5 psi change in the
set #1 RR tire.
Note:
We stand by our cold minimum pressure recommendations. Do not lower air
pressures below our recommendations. Raise pressures on lower spring rated
tires to achieve desired results.
Service Policies
Related to Spring Rated Tires
-We
will do our best to select tires as close as possible in spring rate to each
other.
-We
will not dismount/remount (swap) tires due to spring rates.
-Requests
for specific spring rates cannot be accommodated.
-Customers
are not allowed in service area or in Hoosier trailer.
-No
sorting thru Hoosier wheel sets for date tins or spring rate will be permitted.
Mounting
Mark
On
the outside sidewall of all of our speedway radials is a mounting mark. This
yellow dot indicates the highest spot on the tire. Match this mark up with the
lowest part of your wheel (if known through run-out check) to get the best
possible assembly.
X-Ray
Stamp
On
all Hoosier ARCA Speedway Radial tires you will see a stamp on the outside
sidewall, which consists of an “X” with a circle around it. All Left side
tires have yellow stamps and can be used either in the Left front or a Left
rear position on the car. On the Right side tires you will see either a white
or a yellow stamp. White X-ray stamps can be used in either the Right front or
Right rear position. A Right side tire with a yellow stamp can only be used in
the Right rear position on the car.
Rev
3-15
|
