Fixing the Achilles' Heel of Late Model Mopars – Part 1

600+ horsepower, a set of drag radials at the end of their life span, an upgraded rear axle, permission from Auto Club Famoso Raceway owners John (pictured) and Blake Bowser, and an enthusiastic (OK, maybe maniacal) editorial assistant behind the wheel equals a wickedly fun photo op. You can see the video of this burnout in our YouTube commercial.

In Greek legend, Achilles was one of the most powerful warriors that ever lived. When he was a babay, his mother, fearing a prophecy that he would die in battle, journeyed with him to the River Styx, there to bathe him in its waters, granting him invulnerability. But as she did so, held Achilles by the heel, which was not washed over by the water of the magical river. Sure enough, one day in battle the poisoned arrow of the hero Paris lodged in his weak heel, killing him. The phrase “Achilles' heel” has since come to mean a deadly vulnerability that can lead to downfall in spite of overall strength.

“Overall strength,” reminds us of our beloved late model Challengers, Chargers, Magnums, and 300s. We love these cars because of the strength of their Hemi engines, excellent handling, strong brakes, good looks and reliability. As long as your car is stock or nearly stock, and as long as you stay away from drag strips or sticky tires, the tale ends here.

However, if you can’t resist bolting on some nitrous, or a supercharger, or upgraded heads and cam, or if you like to go to the drag strip and launch on sticky prepped tracks, or any combination of these, then the tale turns dark and “deadly vulnerability” may apply. We are of course talking about the rear axles, specifically the half shafts. Hardly a day goes by without a tale of axle woe being posted on a forum or spread by grapevine at the local track. To put it simply, all 2008 and earlier LX/LC cars have axles that are inadequate for almost any power level above stock, especially if sticky tires or track prep is involved. Starting in 2009, SRTs received upgraded rear ends that seem to hold up pretty well, but of course this is of no help to R/T owners or pre-2009 SRTs.

Since we knew the plans for the Maulin’ Magnum included adding a 150 nitrous shot and then swapping in a supercharger, we knew the axle issue had to be addressed. We made over 350 quarter mile passes this year alone, and expect to see about 500 in 2012. We swear we could hear the axles crying when they heard us talking about these plans.

While we’re at it, we could really use some steeper gears then the 3.06 factory cogs. Our calculations showed that the ideal ratio for the track would be about 3.93 to ensure hitting the finish at red line in fourth gear. However, we have to live with the Maulin’ Magnum on the street. We drive this car from Los Angeles to Las Vegas or Bakersfield twenty times a year, so we needed gears that were more of a street/strip compromise.