Energy Suspension C4 Corvette Upgrade


By Lyle Larson

   Previously reported power upgrades to our "Beyond the Crate " 1995 Corvette project added a 450 HP 383 build and prepped B&M transmission that combined to snap your neck at the touch of the throttle. This immediately highlighted the sloppiness that 180,000 miles had added to its well worn suspension.  The cure was a clear cut path to Energy Suspension in San Clemente, California for a full suspension upgrade with their polyurethane bushing Corvette Hyper Flex Master Kit PN 3-18122 for 1985-95 Corvettes.

   Based on previous experience with Energy Suspension kits we had great expectations and we were not disappointed when the suspension's handling qualities were restored to better than new with road gripping capacity never before seen in this model Corvette. Vice President Michael Santa Cruz  told us the difference with the Energy Suspension master bushing kit would be night and day and he was dead on the money.

   We originally selected an affordable  C4 Corvette because it came equipped with a relatively strong fuel injected engine and world class factory designed performance suspension and universally lauded handling characteristics. This particular one was just worn out, but the Energy boys had the proper remedy in a one-stop shopping box. Follow along here as Energy Suspension master techs Ben Lahatt and Billy Ray Harrill put the tight and bite back in this revitalized thoroughbred.


This job began with the removal and inspection of the front upper control arms. The original factory bushings were cracked, worn and completely shot. They fell apart upon removal so you can imagine how much compliance they added to suspension movement, particularly when the car is driven hard. When your car feels a little mushy in the corners, here's why.
The instructions that come in each Energy suspension kit are clear and thorough. Once the old bushings were pressed out of the control arms, the new polyurethane bushings were installed using a special thick lubricant that comes with the kit. any small press will get the job done as seen here.
After each bushing is installed the inner sleeve is pressed in using the same press technique and appropriately sized supports. When one end is finished, the control arm support mount is inserted and the opposite side bushings are lubed and installed around it.
The inner portion of the control arm mounts are ribbed to provide extra grip for the bushings. These should be cleaned before installing the new bushings. Energy Suspension bushings and components are all clearly marked with part numbers to avoid confusion. Finally, the badly deteriorated ball joint cover will receive a new Energy Suspension polyurethane cover when the unit is reinstalled on the car. Each portion of the suspension has a specific number of bushings in the kit so it is easy to lay them out in order as you progress through the installation.
The crew at Energy Suspension function like a well oiled machine. Here suspension tech experts Billy Harrill (left) and Ben Lahatt (right) confer with Sales Director Mike Papazian about the specific kit used for the Corvette. In particular, they are always looking to identify installation problems or shortcuts that can be updated in the online PDF instruction sheets. They also watch for and note any vehicle changes they discover in case their kits need to be updated to accommodate factory changes on different models. So every installation they perform is also a research opportunity to help them stay current, even with older vehicles. No particular issues were found with the Corvette installation, but they still treated it as learning experience and the opportunity to verify its performance once completed.


The front lower control arms displayed equally distressed condition when removed. They were loose, cracked and broken and only being held together by the control arm housing. They fell apart when removed. Imagine how that was affecting the handling. The bushings are removed and replaced with the same press operation used to install the upper bushings.
The lower control arms also incorporates the front sway bar mount and the kit has a special shaped bushing for it. Once the old bushing is pressed out, a deburring took is use to break the rough edge of the opening. Emory cloth is then used to smooth the edge so it won't cut into the new bushing.
Here the sway bar bushing is installed in the lower control arm. On the table the prepped arm is ready to install and is surrounded by the sway bar mounts and the upper arm from the opposite side waiting to be prepped.


Ben showed us a cool trick for removing the old bushing from the sway bar. A propane torch used to heat the outer housing. when the rubber begins to smoke and bubble at the edges, the bushing easily comes out. Then the sleeve is cleaned and the new bushing is pressed in using the hand press.


Cleaned and revitalized upper control arm with all new bushings. Sway bar mount is easily visible here. The lower half is finished with only the steering arm remaining to connect. Here you can also see the complete sway bar bushing kit assembled. Last photo shows the polyurethane dust covers that replaced all the cracked and broken ones on the ball joints.


Replacing the steering rack bushings is a critical step. Your steering inputs will be imprecise if the rack is moving around. Here are the broken remains of the stock steering rack bushings and the worn out stock sway bar mounts. At center is the new bushing kit and the installed pieces at the right. Don't skip this step because it is too difficult. It is hard to reach but worth it.
This work can be done in your garage if you're patient enough and don't mind working under a car on jack stands. If you have access to a rack that is always the better way to go.


The rear suspension requires just as much attention as the front. The Energy suspension master kit provides all the right pieces to get the job done. at the rear, dual trailing arms with hub mounted spring perch and sway bar setup all require attention. You can swap the trailing arms one at a time as shown here.
Here's a good look at the nasty stuff going on in your high mileage suspension. Even Corvette's get worn out and this rear trailing arm illustrates it perfectly. The sleeve in the bushing has migrated to one end leaving a visible gap where you can actually see past the sleeve and the rubber (lower right side). The same thing occurs at the opposite end of the arm and they are all different due to variations in the prevailing forces acting on them over the life of the car. The bushing is also crushed and cracked which imparts additional springiness to it and allowing far more unwanted movement that the designers ever intended. In this example you can also see a slight crush to the sleeve which indicates not only long term wear, but also some level of hard driving in the car's past. The Energy Suspension master kit provides a convenient and easy to implement solution.
Finished trailing arms easily show the difference with Energy's high performance bushings in place. Installed on the car they completely change the car's personality on the street or at the track.
The well worn rear spring mounts were replaced with the kit's heavy duty polyurethane bushings to stabilize the vital link between the rear hubs and the rear spring.
Here are several views showing the rear hub and stabilizer bar bushings, installed trailing arms and the lower rear control arms.
Working at eye level is a considerable help as Ben demonstrates here. Everything is easy to reach including the tools and the necessary jacks for raising and lowering the suspension components.


The Energy Suspension master kit PN 3-18122 has everything you need to put maximum grip back into your 1984-95 Corvette. It requires only basic hand tools and jack stands and it is a considerable help if you are able to perform the installation on a service rack.
Click the photo of the PDF Parts List to the right to view further information about the Corvette master kit and supplemental part numbers that may apply to your car.
After they come out of the mold, all bushing require trimming so trimming stations are set up to remove excess polyurethane from each part.
Energy Suspension also makes supplemental parts like motor mounts. Here's a metal mount in a mold, ready for the polyurethane to be injected.
Finished small block Chevy motor mounts awaiting trimming and packaging for shipment to Energy suspension customers.


Our thanks to Ben and Billy and VP of Sales and Marketing Michael Santa Cruz (center) Hyper Flex  for setting the Corvette's suspension on Beast Mode with Energy Suspension's Corvette master kit. Michael was right. The difference was night and day. With Mickey Thompson rubber, Hurst wheels, QA1 shocks and Baer Brakes, the Corvette is prime Supercar material.
A brief test drive confirmed all our expectations that the Corvette's suspension and handling characteristics had been revitalized to better than new condition. Can't wait for the next winding canyon road.
For an encore, Michael brought out his 650 horsepower 454 ci LSX powered '69 Camaro so we could snap a few photos with the Corvette. It is one fast machine and we may just have to show it to you in an engine swap feature down the road.


Energy Suspension ®
1131 Via Callejon
San Clemente, California 92673-6230, USA
Toll Free (888) 913-6374
Phone 1(949) 361-3935


Corvette Suspension Bushing Replacement Kit  3-18122

1984 - 1995 Chevrolet Corvette

Performance Polyurethane Master Bushing Sets
  • Get real performance, for both on the road and off.
  • Popular performance car, truck and SUV applications.
  • A real must for competition use, or just for that "seat-of-the-pants" fun!
  • Increases vehicle stability and control as well as durability.
  • Reduces wheel hop and traction loss.
  • Proven for many years, by both professional and amateur racers alike.
  • Both restores and improves better than new!
  • Made of Energy's HYPER FLEX performance polyurethane.
  • Heavy duty metal components are used, for increased strength, when applicable