While building the Sprint Car I kept
noticing that the car wouldn’t set properly from day to day. The
mismatched shocks weren’t technically the correct correct length for the
application and the two rear shocks were some threaded body, no-name
units that were internally limited on the left side and had slotted
pistons coupled with 5,000cst diff oil for shock fluid. The fronts
weren’t much better; the right one was a limited Rustler rear Ultra
shock that was still not the correct length and the left side was a
Bandit front shock that didn’t really have enough travel to match any of
the other three shocks. In the interest of actually having the car
handle it was time to put some quality dampers on the car.
After measuring the lengths of the shocks on the car currently and
comparing those measurements with the chart on Pro-Line’s website (https://blog.prolineracing.com/2016/…-download-now/)
I settled on a pair of 6308-31 rear SC shocks for the right side of the
car and 6308-30 fronts for the left side. I also ordered the tuning
springs sets for the front and rear to have some options to set the
corner balance of the car as well as a hardware mounting kit just to be
safe. The mounting kit wasn’t absolutely required but it was helpful in
getting everything 100% dialed.
Out of the box the shocks only require being filled with oil and
installed on the car. I filled the shocks with 35wt shock oil all around
which seems to be a good match for the included medium rate springs.
Straight out of the package the ride height was a little low in the
right rear as well as both sides of the front while the left rear was
just about perfect. Winding in a little preload on those three corners
got the chassis sitting level with no fuss. I did notice that the
preload collars are a little stiff at first and take some effort to
turn. I would rather see them be a little firmer than spin freely and
possibly change the preload setting during a run.
Cycling the shocks through their travel, even without oil, rewards you
with the smoothest action with no shaft play or stiction. These shocks
are even smoother than the units included with the Pro Fusion SC 4×4,
which I previously thought had the smoothest shocks I’d ever used. The
included white delrin pistons and shaft guides attribute to the
smoothness but it is the attention to detail in the assembly that makes
the difference and Pro-Line definitely got it right with these.
My first run with the new shocks was on freshly laid Ozite. My neighbor
offered his recently renovated storefront to try the car out; he had
never tried RC before and was intrigued by what I had going on when I
was setting the trims in the driveway. The store didn’t have its
fixtures installed yet and measured around 800 square feet. We set up an
oval on the carpet using some shoe boxes and took turns putting around
with the car for the first pack. He was having a blast and I was taking
note of how the car was turning in and checking for any odd motion in
the chassis while accelerating and braking. The car looked composed but
at such a low speed that wasn’t too surprising.
After dropping in a freshly charged battery it was time to drop the
hammer. The car has a ton of forward traction, carrying the left front
from corner exit to corner entry. I may try a slightly firmer right rear
spring or a few more millimeters of preload to calm down the amount of
tweak that the current setup has. Once the throttle is released on
corner entry the car takes a set without any drama and stays planted
through the corner with no need to chop the throttle or stab the brakes
to put more weight on the nose. There was no chatter from the front
tires even when I over-cooked it on corner entry. At no point did the
rear become unsettled to the point of causing a spin. The car is easy to
drive and easy to drive fast. The run was cut short due to a grenaded
transmission but it did show promise that the setup was going to work.
Overall, the Pro-Spec shocks really impressed me with their smoothness
and how well they performed on the car. They look great with their
anodized blue accents and polished finish. The inclusion of delrin
pistons (both installed and optional tuning pistons) as well as delrin
shaft guides are a standout feature for SC shocks and the firm feel of
the preload collars was a pleasant surprise. I highly recommend these
dampers to anyone looking to take their SC truck to the next level of
performance.
The whole package:
The rear 6308-31 units:
The 6308-30 front dampers:
The tuning springs and mounting hardware:
The finished installation:
The “rear” length shocks on the right front:
The “rear” length shocks on the right rear:
The “front” length shocks on the left front:
The “front” length shocks on the left rear:
Links:
Rear https://www.prolineracing.com/perfor…hocks-rear.asp
Rear Tuning Springs https://www.prolineracing.com/perfor…rings-rear.asp
Front https://www.prolineracing.com/perfor…ocks-front.asp
Front Tuning Springs https://www.prolineracing.com/perfor…ings-front.asp
Universal Mounting Hardware Kit https://www.prolineracing.com/perfor…rdware-kit.asp