Polyurethane is an advanced product that flexes far less than rubber, but still allows a certain amount of isolation between the car's chassis components and the car itself. Energy Suspension has more than twenty years of experience with polyurethane, and their Hyper-Flex performance polyurethane is a proprietary, technically advanced formula that has earned them nine U.S. patents. Unlike rubber, Hyper-Flex performance polyurethane components don't compress from weight or road forces, and won't rot or deteriorate due to exposure to oil, chemicals, or road salt. Hyper-Flex components are a free-floating, non-binding design, and Energy Suspension track tests all of their products before bringing them to market. The Energy Suspension Hyper-Flex components are available in red or black, both offering the same basic chemical polyurethane formula, with graphite added to some of the black bushings for additional lubrication. For our Challenger, we chose a full set of front and rear bushings in red, and decided to test our car on the track to determine how much of a difference these bushings make. To establish a performance baseline for our Challenger, we took the car to Auto-Plus Raceway in Gainesville, Florida, for some timed laps around their road course. With the factory rubber bushings in our Challenger's suspension, our car turned lap times of 1:16.6 and 1:16.5 on its best two laps. With our baseline established, we took the car to Inline Performance Specialists in nearby Bushnell, Florida, to install our Energy Suspension Hyper-Flex polyurethane bushings.

Installing new suspension bushings in a late model Mopar is fairly straight forward, and requires basic tools found in most automotive shops. Inline Performance specializes in Mopar vehicles, so they quickly got busy removing the factory rubber bushings to replace them with the new polyurethane units. Up front the control arms and various components can be removed individually, the rubber bushings removed, and the Hyper-Flex bushings installed before reinstalling each component. In addition to the control arm bushings, we also installed Hyper-Flex bushings in the rack and pinion mount locations, and the shock mounts.

Since the rear suspension of the Challenger is encompassed in a cradle that is held to the car's subframe with four bolts, it's easiest to remove the drive shaft and calipers, then drop the entire rear IRS “unit” from the car to perform the suspension work. With the rear suspension and cradle on the shop floor, it's easy to access all of the suspension components, and again the rubber bushings can be removed and the Hyper-Flex polyurethane bushings installed in their place. All told, we had the front and rear bushings replaced in a day's work, and checked the car's wheel alignment to make sure it was still within the factory specifications.

On the way back to Auto-Plus Raceway to re-test our Challenger's handling, we noticed that our car definitely felt more connected to the road. Ride quality was somewhat stiffer, but still comfortable, and the car definitely took the corners flatter, without the body roll associated with the flexible rubber bushings. On the road course at Auto-Plus Raceway, we made a couple of warm up laps and then made two back to back test laps. The car felt quicker around the course not just through the corners, but when accelerating off of the corners as well. On stock tires, our lap times during our test laps dropped to 1:14.1 seconds for each of the two laps. This is a reduction of more than two seconds from our baseline laps, a clear indication that the Energy Suspension Hyper-Flex performance polyurethane bushings made a dramatic difference in our car's handling.

Here at Mopar Muscle there are times when we test products and don't see the results we expect. During this test, however, it was clear that the Energy Suspension products made a big difference that we not only felt in the seat of our pants, but saw in reduced lap times on the road course. The improvements we saw were on the stock tires that our Challenger came with from the factory, and we feel that stickier compound tires would really benefit our car now that the chassis and suspension have less flex. If you have a late-model Mopar, we encourage you to visit Energy Suspension's website and check out the Hyper-Flex components they make for your car, we can say from our testing and experience that these products do make a difference.

Part Cost
Rear sub-frame bushings $195.99
Rear control arm bushings $101.38
Rear differential bushings $48.99
Rear lower shock mount bushings $71.99
Rear sway bar and end link bushings $29.99
Rear trailing arm front bushings $31.41
Rear trailing arm rear bushings $41.41
Front control arm bushings $135.95
Front lower shock mount bushings $71.99
Front sway bar bushings $13.99
Rack and pinion bushings $23.99

Lap Times - Stock

  • 1:16.6
  • 1:15.5
Lap Times with Hyper-Flex Bushings
  • 1:14.1
  • 1:14.1

Auto Plus Raceway at Gainesville
Inline Performance Specialist
Energy Suspension
1131 Via Callejon
San Clemente