Projects

A big part of making top-quality leaf-spring suspensions is actually testing them in the real world.

We'll use this page to show you some of Alcan's R&D projects and to share some of the info, tips and tricks we learn.

In the case of 4x4s, R&D means we have to tackle some of the gnarliest trails in some of the most beautiful countryside there is. It's a tough job, as they say, but...

If you're a CJ or Wrangler owner who's considering a spring-over-axle swap, you'll be especially interested in Project "Good-Better-Best."

Over the next few months, we'll test and compare this '79 CJ-7 with:

• 5 1/2-inch spring-under lift
• 1-inch spring-over lift (total of 6-to-6 1/2 inches of lift)
• 1-inch spring-over lift with A.O.R. Orbit-Eyes instead of traditional poly bushings

A great advantage of using Alcan custom springs is that we can change the wheelbase by moving the springs' center pins. This CJ's stock wheelbase was 92 inches, but with Alcan Springs, the wheelbase is 96 inches--better for most trail situations and better on the highway, too.

Alcan's test CJ-7 has Dana 44 axles at both ends, and 33x12.50/15 tires. We first ramped it with 5 1/2-inch Alcan Springs in the stock under-axle position.

The spring-under CJ scored an RTI (ramp travel index) of 865 on a standard 23-degree ramp.  Note: To calculate RTI, we measure the distance the 4x4 travels up the ramp before a rear tire lifts off the ground.  That number is divided by the 4x4's wheelbase, then multiplied by 1000.  RTI numbers are useful to judge how suspension modifications affect the same 4x4.

865 is a pretty good ramp number for general all-around 'wheeling. But as 'wheelers try tougher trails, many find the spring-under's limited ground clearance is a real drag (literally). That's when a spring-over swap looks attractive...

  Here's a preview of the spring-over swap.  We'll post the details when we're finished with the testing.  So check back often...