As every Drag Racer knows, consistency wins championships. John Calvert has achieved championship status in the highly competitive field of NHRA drag racing. He has 20 plus years of racing experience over every type of track condition imaginable. John has won most of his races in a 1968 Ford 428 cu/in powered Cobra Jet Mustang. He knows the idiosyncrasies and potentials of his car without question; He knows the importance of understanding and fine tuning all the components needed for repeated successful performance. His experience and success over the years with his car provide him with an excellent base line from which to create more efficient modifications. It has in this experimental role that John and his skilled friend Larry Kieser developed the CALTRACS traction enhancement system.
In Stock Class, where John's major racing endeavor has been shaped, NHRA dictates that a maximum of 9" slicks can be used. This presents a racing dilemma to a driver when trying to couple big block power to the ground. The CALTRACS design was developed in John's garage. Brainstorming together, Larry and John created the design and the first model of the system. CALTRACS augments the car and driver potential to specific performance goals while complying with hard set NHRA class parameters.
John's concept won the enthusiastic approval of his family. Two brothers, Keith and Paul and Dad, Bernerd all share a talent and fascination for the world of mechanical engineering. Combined they hold over 75 years of career involvement in Aerospace engineering and production.
CALTRACS has been distributed to Europe for serious competitors there. If you travel to Sweden, there's a good chance you would see a set of CALTRACS in action.
Tremendous benefits can be realized when the CALTRACS traction bar system is installed on a leaf spring suspended automobile. CALTRACS traction bars were developed to achieve specific goals to improve high power traction while staying within hard set NHRA parameters.
Each of the two assemblies needed is comprised of three basic components:
-
Front Pivot
-
Force Transfer Link
-
Rear Mount
The combination of these components changes the pushing point on the car by redirecting the turning action (spring wrap-up) of the rear axle through the Force Transfer Link into the Front Pivot. The Front Pivot Spring Stop Bolt resists this turning motion and also controls the bending of the leaf spring at its thinnest section. The push into the Front Pivot helps the cars weight shift towards the rear of the car because of a new directed angle of force toward the front of the vehicle. (The "Instant Center" moves farther forward). This is where the system emulates a Four link system. The pinion angle is also maintained.
1. The Front Pivot
Two steel plates sandwich the leaf spring sides. Two attach points in the plates provide the user with a selection in which the forward Force Transfer Link rod end can be located. A machined aluminum spring eye bushing and steel insert supports the front of the spring while allowing the plates to pivot. A spring stop bolt controls and restricts spring wrap-up. Spacers are provided for different vehicle applications that control clearances in the front spring eye pocket.
| 2. Force Transfer Link
This is a length of chromolly tubing with CNC machined threaded inserts TIG welded into each end. The front Insert is machined with right hand Threads and a HEX outer shape for Simple wrench adjustment of the Installed assembly. The rear insert is Left hand threaded. Opposite thread Styles at each end provide the means to easily lengthen or shorten the link for desired pre-load adjustment.
|
|
3. Rear Mount
A welded ?" steel assembly replaces the original vehicles spring perch and incorporates the mounting provisions for the rear rod end of the Force Transfer Link.
Installing the CALTRACS is very straightforward. Raise and support the car high enough to remove the rear tires. Allow adequate working space. Next, the rear spring assemblies should be removed. This will facilitate replacement of the front eye bushings. Support the rear end housing in place while the springs are out. This will eliminate the need to disconnect the drive shaft, brake lines etc. Press or have pressed, the original front eye bushing out of each spring assembly. Replace these with the machined aluminum CALTRACS bushings supplied in the kit. Now, reinstall the rear springs into the car.
With each spring assembly ready to go in, position the forward pivot assembly to the front spring eye. (Assure that the Spring Stop Bolt is located on the upper surface of the spring.) Install the Steel Bushing through the pivot and front spring eye bushing. Now, reinstall the spring using the original hardware. Repeat the process for the other side.
Lower the rear axle assembly on to the springs. Install the supplied spring perches as you would the stock items being replaced. Attach the shocks.
Now the Force Transfer Link can be installed by starting the HEX (wrenching) end on to the forward rod end. Remove the rear rod end from the spring perch and start its threads into the rear Force Transfer Link. Adjust the assembly to proper length by holding the rear rod end then rotating the Force Transfer Link until the rear rod end will line up with the mounting hole in the rear spring perch. Install the rear rod end fastener and secure.
With the CALTRACS installed and the rear tires reinstalled, lower the car to the ground. As an initial setting, turn the Force Transfer Link until the spring Stop Bolt just contacts the upper surface of the spring, then turn the Force Transfer Link one turn more to establish pre-load. Tighten the Force Transfer Link lock nut. That's it!
