Tips & Tricks

10 Tips to Better Handling

C4 ('84-'96) suspension secrets

By Cam Benty



Those '84 through '96 Corvettes are everywhere. Cheap and fast, they are, as Dick Guldstrand would say, "America's hot rods of today." Best of all, parts for these vintage Corvettes are readily available and the cars are easy to work on. So how come they have such suspension handling woes?

Well here's a chance to fix up your C4 and have it ready for the Solo I competition in your town next weekend. The following are 10 tips from the great mind of legendary Corvette race driver Dick Guldstrand to help get your Corvette handling like a dream. The vehicle used to demonstrate our "10 improvements" was one of Dick Guldstrand's original GS 80 cars used for the detail photography within this story. For a time, this specific GS 80 held the closed-course record of over 170 mph at the Talladega International Raceway. A good testbed for suspension pieces for your Corvette? We think so.


1. Ditch the rubber. As these cars reach the 100,000 or more mile marker, it's time to get rid of the rubber bushings and firm up the suspension. Rubber is a great compromise for the factory, but you don't have to put up with it. Best of all, while polyurethane used to be so hard that it became a torsional piece of the suspension, these days polyurethane has advanced and become more compliant, cushioning suspension dynamics. Lubricate the pieces adequately upon installation to help break in and avoid that annoying polyurethane squeak.



2. Make it safe. These cars are certainly aging. At least do a check of the firmness of the front-end ball joints, wheel bearings, and brakes to make certain they are not allowing the wheel to move out of alignment. This is a simple check that can reap big rewards. As Guldstrand always notes, "We want the customer safe long enough to pay his bill. Suspension first, engine second." This '88 Corvette held the closed-course record at Talladega for several years. This was the testbed for many Guldstrand Motorsports components, which are engineered to handle any standard street challenge as well as Solo I, autocross competition, and beyond.

3. Ditch the pre-'88 single-disc front calipers. If you have the '84 through '87 calipers, upgrade to the dual-piston units used starting in 1988. The earlier calipers were woefully inadequate and the changeover is simple. Moving up to an aftermarket caliper like the Baer Racing EradiSpeed calipers/rotor package is a great idea.

4. Consider switching to coilover shocks. Here's a radical thought: Get rid of the transverse leaf springs and mount up coilover shocks. Bilstein makes coilover shocks that bolt right into the stock shock mounts (slight widening of the shock mount is required up front). With the high cost of replacement transverse leaf springs, this may not be as expensive a swap as you might think, and you can reduce the weight of the suspension by completely removing the leaf springs. Special bonus! With the coilovers, you can adjust the ride height of your Corvette for different tire and wheel packages in a matter of minutes. Try that with your leaf springs


10 Tips to Better Handling (cont.)

5. Change your brake pads. For high-performance street action, Guldstrand recommends Performance Friction's Z-rated pad for great grip and no heat-up. If you're going autocrossing, where you will let the brakes cool between runs, go with the 01-rated pads (caution--these are not recommended for street-driven cars).

6. Change your sway bar. Sway bars actually reduce sway, as opposed to the name. With Corvettes of this vintage, a big sway bar is not required. Remember the sway bar is a tuning device and you should be conservative in your selection. This rear sway bar was used at the Bridgestone test day and measures 24mm. Sway bars should be used to tune the suspension to driver taste.

7. Install a toe-control rod. The rear suspension is challenged to hold its ground against the power of the road. In many cases the toe-control rods on stock C4 Corvettes are bent or broken, affecting the toe on the rear tires mounted to the independent rear suspension. Using an upgraded toe-control-rod system that mounts to the rear end and replaces the weak factory unit, you can ensure that toe adjustment tolerances will be held tight. The more solidly suspension components are mounted, the better chance they will keep the tires moving in the right direction. This camber toe bar is built to replace the factory bars, which are mounted in rubber and far less "beefy" than these Guldstrand units.

8. Upgrade your leaf springs. If you don't want to go the entire way and replace your leaf springs with coilover units, at least upgrade to the factory Z51 leaf springs. These springs are great at keeping ground-to-tire contact at the optimum.

9. Tires--bigger is better. So how big can you go with tires for your C4? "Until they hit the wheelwells and then some," says Guldstrand. The key here is to go as big as you can handle. According to Guldstrand, some autocross cars are running 18x12-inch wheels with 305- and 315-width tires. This is a bit much for the street. Guldstrand recommends 18-inch wheel-mounted tires because there are a variety of different sizes and brands available. You should be able to get between 275- and 295-width tires on these cars without difficulty. Guldstrand uses Fikse wheels for their light weight and strength, 18x11 inches in rear, 18x9 to 10 inches in front.

10. Use Heim joints when possible and legal. For serious racing and when ultimate performance is needed, Heim joints are used to link the sway bars to the chassis. This greatly increases the effective nature of the bar. Unfortunately, some autocross and Solo I classes do not allow for this modification. It should be noted that Heim joints also transfer road harshness to the frame and, in turn, to the occupants of the vehicle. But for those of you tough enough to handle the ultimate suspension components... These sway bars feature Heim-jointed end links, which are the most efficient at maximizing sway-bar leverage. They do, however, transfer more road noise to the occupants than standard-style links and may not be legal for autocross competition.



Baer Brake Systems
(602) 233-1411

Bilstein Shock Absorbers
(858) 453-7723


Guldstrand Motorsports
(818) 558-1499

Performance Friction Corp.
(800) 521-8874