Customer service has always been a core value at JR Race Car. We are here to support the junior community with advice and suggestions about all makes and models. Our tech line is open Mon - Thu 8am-5pm and Fri 8am-noon.

Check back often for new and updated tech articles.  Don't forget to print them off and take them to the track.

Engine Documents

Engine Brakein Guide
Rebuild or new engine ware in procedure. These are recommendations for JR Brand Engines.
Carburetor Tuning
Carburetor tuning indicators guide. A quick chart the suggest carburetor adjustments.
Round Fuel Pump Routing Diagram
The Mikuni round fuel pump is not as simple to install as other pumps. This is a guide for plumbing the round fuel pump.
Timing 101
A how to guide to setting timing for analog ignition coils without a flywheel key.
Kill Switch Wiring
Proper engine cut off is a critical safety component of any dragster. This is a guide to setting up both electrical and manual engine kill switches.
Titan Exploded Parts
Engine basics, a diagram showing all the parts and components to a Titan engine. The basic layout is consistent with all flat head engines.
Engine Rebuild Instructions
Please print this form out and send it in the box with your engine for rebuild.
Engine Tuning and gearing suggestions for a Rater Engine
ZR (Stage 8&9)
Engine Tuning guide with gearing and clutching for ZR3 Engines
ZR4 (all bores)
ZR4 Tuning and gearing guide
Titan (all bores)
Titan Engine setup guide

Shockwave Clutch Documents

Shockwave Maintenance Guide
Disassembly and reassembly instructions for the Shockwave Clutch
Reverse Driven Maintenance Guide
Disassembly and reassembly instruction for Reverse Driven
Alignment Guide
Belt alignment diagram for Shockwave and Shockwave OD clutch
Clutch Vocabulary Sheet
A peace and part guide to the Shockwave clutch.
Shockwave Tuning Chart
Weight and spring combinations for the Shockwave family of clutches.
C-4 Flyweight
History and application for the C-4 style flyweight.
C-14 Flyweight
Application of the C-14 style weight developed for outlaw racing.
H-1 Flyweight
History and application of the overdrive H-1 style flyweight.
C-15 Flyweight
Application and history of the early outlaw flyweight C-15
C-2 Flyweight
History and application of the original overdrive C-2 style flyweight.

Chassis Documents

Hercules Axle Assembly Guide
Step by step guide to JR Pro axle setup and installation.
Hercules Brake Assembly Guide
How to guide for installing the JR PRO floating caliper on the Hercules chassis.
Beadlock Installation Instructions
Torque spec and setup information on JR Beacklock wheels.
Center Pull Motor Plate Guide
Exploded center pull motor plate view with part list.
Ballast Guide
Chassis ballets, where to pack on the pounds to effect tracking, reaction time, and more.
Tire Comparison Guide
Side by side comparison guide for front and rear tires. Actual measurements and sizing.