2024 & Up Junior Sprint Setup

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Setup Table

	Left Front	Right Front	Left Rear	Right Rear
Torsion Bar / Coil Size	60#	80#	.630	.670
Block Size	2"	2"	1-1/2"	1-1/2"
# of Turns Off Block	+0	0	+0	+1
Ride Heights	**
Shocks	25-60R-25C	25-60R-25C	40-100R-30C	40-80R-40-100C
Center Line of Tire Offset	9-1/2	14	8	15–16
Tire Pressure	10 psi	10 psi	5–9 psi	7–10 psi
Tires	15X6-8	15X6-8	15X8-8 or 15x7-8	16X8.5-8
Wheels	8x6 (3" outer)	8x6 (3" outer)	8x6 (3" outer)	8x8 (5" outer)
Stagger	3"–4"
Jacob’s Ladder	Outer Frame Holes
Front Panhard	3"

Setup Notes

Start with the 33½" front axle and the 48½" long rear axle.
Make sure your car is set up with axles square, caster set, offset checked, and chain aligned and tensioned.
Note: 1 turn equals 4 clicks.
Adjustable front shocks: Start full stiff (full clockwise on the adjuster knob) minus 2 turns (8 clicks).
Adjustable left rear shock: Start full stiff minus 2 turns (8 clicks).
Double Adjustable Shock — Right Rear (DAS RR): Full stiff on both compression and rebound, minus 2 turns compression and 2½ turns rebound.
Measure the RR offset from the frame to the center of the rear tire directly above the rear axle.
Rolling resistance and rotating weight is very important on the Junior Sprints. Do all you can to reduce it.
Keep the center of gravity low. Mount the seat as low as practical while allowing the driver to see adequately.
Generally throughout the night, all that is needed on the chassis adjustments is tire pressure and right rear offset. You really do not need to do too much to these cars.

Chassis Adjustments

Move right rear tire in (15")
Move wing back
Go to less stagger (as little as 2¾")
Reduce LR tie down, reduce front tie down, reduce RR compression, add RR rebound
Lower rear tire pressure
Lower rear roll center by moving the paddle down on the RR bearing carrier
Stiffer LR bar (.650 or .670)

Gearing & Engine Notes

Gearing a Junior Sprint can be difficult without the use of a Mychron. Gear the engine so that it hits the limiter about 5 feet before entry.
If the engine has a loud bang at the top end when it hits the limiter, the fuel mixture is too lean. This could be the jetting or the float height setting.
Do not transport the car with the carburetor on without fuel in it — it is likely to cause the floats to fall out of adjustment.
Clean the methanol out of the carburetor very soon after the race or first thing the next morning. Fog the engine with INOX MX3.
Do all you can to keep the clutch in good shape. Don’t use the clutch any more than necessary. For example, push the car to the starting grid instead of using the clutch to get there.

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