Axle wrap and spinning tires equal broken parts, bald tires and a slower truck. What good does all that added power under the hood do if you can't get it to the ground?
You've built up that motor, beefed up your transmission and now all you're doing is roasting tires on the asphalt. It's time to look at traction aids, time to make those tires bite and make your truck feel as strong as it really is. Whether you're into drag racing, off-roading or just need better traction for all-around daily driving, Calvert Racing of Lancaster, CA, can help plant those tires to the pavement and transfer that horsepower to the ground.
Calvert Racing has been the leader in leaf-spring traction aid devices for more than 15 years. Most popular in the drag racing market, Calvert Racing's Cal-Tracs offer better bite and more traction than any other traction bar on the market. Engineered specifically to not only help prevent axle wrap, they actually increase the down force on your rear axle, improving traction.
We spoke with Scott Schwinning of Calvert Racing about the PSD Resurrection story we've been working on the past couple issues, looking to improve the 2wd truck's traction with its new-found horsepower levels. Schwinning suggested we try out a set of their Cal-Trac bars and see what we thought. Since we could go through a set of rear tires in no time at all, we figured it was worth a shot. While big nasty burnout marks are cool, it really hurts performance and speed.
Before installing the Cal-Tracs on our test truck, we wanted to know how these things actually worked. What is it that makes the Calvert traction bars plant the rear tires and offer better traction than the other aftermarket ladder bar setups?
Talking with Schwinning we were really able to get a grasp on what makes Cal-Tracs work. While most ladder bar setups on the market today are offered as "traction bars," Schwinning says that's really just a marketing thing. A ladder bar that connects your rear axle to the frame rail does little to actually add or improve traction. A better term for those style bars would be axle wrap bars. Adding that style of bar will help prevent your axle from wrapping under hard acceleration but it does nothing to add down force on your axle and tires, which would increase traction.
Cal-Tracs work a little different. The Calvert Racing bars actually connect from your rear axle to a triangular-shaped bracket that is mounted to your front leaf spring eyelet. The lower hole in this triangle bracket attaches to the new bar, the center hole is aligned with the leaf spring eyelet and the top hole has a pin through it that will ride on top of the leaf spring pack. As you get into the throttle your axle will have a tendency to wrap, which will force the new bar connected to it forward, which in turn will pivot at the front lead eyelet and that forces the pin through that rides on the springs downwards into the spring pack itself. This downward force of the pin on the leaf springs actually causes down force on the entire axle assembly and forces your tires down onto the pavement harder. So the harder you're on the throttle, the harder the downward force on your tires. No more spinning tires.
While many believe that Cal-Tracs are strictly for drag racing applications, Schwinning suggests that a properly adjusted Cal-Trac setup could improve traction for just about any application, from heavy towing, off-roading and just daily driving. Maybe you don't have issues with traction on the street but do you still get a hopping or chatter feeling from your rear end while towing heavy loads? Most likely you're feeling the effects of axle wrap-again, something Cal-Tracs can help prevent.
If you're in the market for a well performing and inexpensive traction aid for your pickup, we'd strongly suggest giving Calvert Racing a call. The company can build Cal-Tracs to fit just about any truck application, from stock to lifted vehicles. Stay tuned for upcoming issues of Diesel Tech Magazine where we'll be posting up some actual data from the benefits of Cal-Trac traction bars.
1. We started out the install by spraying some penetrate oil on the factory U-bolts and nuts. Once it soaked for a while we removed the factory pieces. You will not be reusing these U-bolts and nuts.
2. While the job could be done with hand tools, it's definitely a job that will go much quicker and easier with a good impact wrench.
3. Once the old U-bolts are removed and you remove the front and rear leaf spring bolts you can remove the leaf springs from the truck. A good hydraulic jack makes swapping out the front rubber leaf spring bushings a breeze. Just press out the old ones and press in the new aluminum bushing supplied with the Cal-Tracs.
4. Here is the new Cal-Trac aluminum bushing next the factory rubber unit. A little tip, if you place the aluminum bushing in the freezer overnight, the material will shrink up just a little, which will make pressing it into the leaf springs a little easier.
5. Reinstall the leaf springs under the truck, but before bolting up the front eye into the factory mount, you'll need to slip the Cal-Trac bracket over the eye so the slide pin rides on top of the leaf pack. There is a steel bushing that will slip through the bracket and aluminum bushing installed in the leaf eye. Once the bracket and steel bushing are in place, you can install the factory mounting bolt.
6. Once the front and rear of the spring is bolted back in place, you can raise the axle back up and install the new squared U-bolts supplied with the Cal-Tracs and the new rear-mounting bracket below the axle. Once the nuts are tightened up you can cut off the remaining threads on the U-bolts.
7. With both mounting brackets installed you can then thread the Cal-Trac bar to connect them. Follow the instructions supplied with the kit closely for proper installation. Once the bar is installed you can put the tires back on and put the truck back on the ground.
8. With the truck sitting on the ground, you can now adjust the bar length. Calvert Racing suggests adjusting the bar length so that the top slide pin is just barely contacting the leaf springs. For a harder and firmer load to the rear axle, adjust the length of the bars so the slide pin rides above the leaf, say an eighth-inch gap between them. Each truck will react to the preload on the bars differently some fine-tuning will need to be done.